In one study, 167 participants with overweight or obesity (BMI 25–40) took a supplement containing kola nut (192 mg/day caffeine) and ma huang (90 mg/day ephedrine) or placebo . Participants who received the extract had significantly lower body weight, body fat, and waist circumference at the end of the trial than those taking a placebo. In the 1990s, ephedra—frequently combined with caffeine—was a popular ingredient in dietary supplements sold for weight loss and to enhance athletic performance. However, dietary supplements containing Garcinia cambogia have been implicated in three cases of mania, which might have been caused by the serotonergic activity of HCA . In humans, however, the evidence on whether Garcinia cambogia or HCA is effective for weight loss is conflicting, and any effects it has appear to be small 6,17, . This 16-week trial used Xanthigen, a dietary supplement containing brown seaweed extract and pomegranate-seed oil . Researchers have suggested that CLA enhances weight loss by increasing lipolysis and fatty acid oxidation in skeletal muscle, reducing lipogenesis, and promoting apoptosis in adipose tissue 17,110. The same Coleus forskohlii extract and dose were evaluated in another 12-week randomized double-blind trial involving 30 men who were overweight (BMI ≥26) . Also in 2013, a systematic review and meta-analysis of 11 randomized controlled trials (including most of the trials evaluated in the Cochrane Review) examined the effects of chromium supplementation in a total of 866 individuals with overweight or obesity .It is also available in many dietary supplements, and humans synthesize it naturally when their skin is exposed to sunlight.Additional trials with larger samples and diverse populations are needed to determine whether Irvingia gabonensis extract is effective for weight loss .Similarly, a 2014 meta-analysis of eight trials that included 301 participants found that glucomannan did not significantly affect weight loss compared to placebo .Hexavalent chromium (chromium VI) is toxic and not found in food or dietary supplements.Women receiving Garcinia cambogia lost significantly more weight (3.7 kg) than those receiving placebo (2.4 kg).For example, protein and other components of dairy products might modulate appetite-regulating hormones .All of these factors can make it difficult to compare the results of one study with those of another. Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. It increases the amount of insulin produced by your body, which then reduces the level of sugar in your blood. This makes you feel fuller or less hungry with fewer cravings for food, helping you to eat less and lose weight. Semaglutide injections should be given once each week on the same day each week. However, because ingredients might not be standardized and many products contain proprietary blends of ingredients, the active compounds and their amounts might not be comparable among products .In a small study, 12 healthy men and 12 healthy women (BMI 20–36) followed the same diet for 12 days (five meals per day with 38% of energy from fat) .The authors commented that the cause of this finding might have been stored vitamin D in body fat and skeletal muscle that was released during weight loss.However, according to a large national survey, less than one-third of U.S. adults who use weight-loss dietary supplements discuss this use with a health care professional .Toxicology studies in rats and mice show that green tea extract does not cause cancer but does cause nonneoplastic lesions in many areas of the body, including the nose, liver, and bone marrow .As soluble dietary fibers, beta-glucans are proposed to increase satiety and gastrointestinal transit time and to slow glucose absorption .The various isomeric forms of CLA include c9,t11-CLA and t10,c12-CLA, and it is available in dietary supplements as a triacylglycerol or as a free fatty acid .However, the authors noted that most of the studies had methodological issues; when they considered the two rigorously designed trials only (which used 1,500 mg/day and 2,800 mg/day HCA), the effect was no longer statistically significant. Medicine information Reported adverse effects for guar gum are primarily gastrointestinal and include abdominal pain, flatulence, diarrhea, increased number of bowel movements, nausea, and cramps 174,176,177. Trial participants included people with hypercholesterolemia, hyperlipidemia, or type 1 or type 2 diabetes; menopausal women; and healthy volunteers. The authors of a review of guar gum’s effects on appetite control concluded that a dose of 2–5 g increases satiety and reduces the frequency of between-meal snacking . Guar gum is a soluble dietary fiber derived from seeds of the Indian cluster bean Cyamopsis tetragonolobus 16,174. Green coffee bean extract appears to be well tolerated, but its safety has not been rigorously studied. Compared to those taking placebo, those receiving Phaseolus vulgaris lost significantly more body weight (mean loss of 2.91 kg vs. 0.92 kg for placebo) and body fat (2.23 kg vs. 0.65 kg for placebo). After 30 days, those receiving Phaseolus vulgaris extract lost significantly more weight (mean weight loss 2.93 kg) than those receiving placebo (mean weight loss 0.35 kg). Phaseolus vulgaris extract is an ingredient in some weight-loss dietary supplements marketed as carbohydrate- or starch-absorption blockers. In another study, 400 International Units (IU)/day vitamin D and 1,000 mg/day calcium supplementation slightly, but significantly, reduced weight gain compared to placebo in postmenopausal women, especially those with a baseline total calcium intake of less than 1,200 mg/day . Compared to the placebo group, those receiving METABO lost significantly more body weight (mean loss of 1.9 kg vs. 0.4 kg for placebo) and fat mass. After FDA banned the use of ephedrine alkaloids in dietary supplements in 2004 see section on ephedra (má huáng), manufacturers replaced ephedra with bitter orange in many products; thus, bitter orange became known as an ephedra substitute . In one of these studies, 66 women who were overweight followed a low-calorie diet (designed to produce a 0.5 kg/week weight loss) for 3 months that was supplemented with 5–6 g/day beta-glucan (from oat bran), 8–9 g/day beta-glucan, or no beta-glucan (control) . Several studies have investigated the effects of beta-glucans on blood lipids, blood pressure, and insulin resistance, with weight loss as a secondary outcome. The authors noted, however, that the trials included in the review used different study methodologies, small samples, short intervention periods, and varying daily doses of Irvingia gabonensis extract (300 mg to 3,150 mg); in addition, the trials were all conducted by the same authors. However, 2 g/day L-carnitine alone for 6 months did not affect weight loss in 94 men and women who were overweight and had newly diagnosed type 2 diabetes . However, in subgroup analyses, calcium did reduce body weight in some groups, including children, adolescents, adult men, premenopausal women, women older than 60, and people with normal BMI . These reviews include a 2009 evidence report from the Agency for Healthcare Research and Quality whose authors concluded that, overall, clinical trial results do not support an effect of calcium supplementation on weight . Second, calcium from food or supplements might bind to small amounts of dietary fat in the digestive tract and prevent absorption of this fat 59,62,63. As a result, consumers might not be aware that the presence of certain herbs means that a product contains caffeine and possibly other stimulants .In a double-blind, placebo-controlled trial, 26 men and women who were overweight (BMI ≥25) were given 6 g/day pyruvate or placebo for 6 weeks .In the 1990s, ephedra—frequently combined with caffeine—was a popular ingredient in dietary supplements sold for weight loss and to enhance athletic performance.Semaglutide also has other effects on your body.However, 25 of the 70 participants dropped out of the study, and results were reported for only the 45 participants who completed the study (i.e., the authors did not complete an intention-to-treat analysis).Manufacturers market these products with various claims, including that these products reduce macronutrient absorption, appetite, body fat, and weight and increase metabolism and thermogenesis. Available green tea extracts cover the range from minimally processed tea leaves to highly processed, manufactured concentrates of single constituents, such as EGCG. Green coffee extract, probably because of its chlorogenic acid content, inhibits fat accumulation in mice and humans by regulating adipogenesis. Glucomannan is a soluble dietary fiber derived from konjac root (Amorphophallus konjac) that can absorb up to 50 times its weight in water . Side effects of probiotics are usually minor and consist of self-limited gastrointestinal symptoms, such as gas. Much of the research on probiotics and its influence on the gut microbiota and obesity has been in mice, and the results have been promising. However, manipulating the gut microbiota has been proposed as a method to prevent or treat obesity in humans, and probiotics might provide a way to accomplish this. Chromium Toxicology studies in rats and mice show that green tea extract does not cause cancer but does cause nonneoplastic lesions in many areas of the body, including the nose, liver, and bone marrow . Taken together, the findings of these studies suggest that if green tea is an effective weight-loss aid, any effect it has is small and not likely to be clinically relevant 164,165. In 2010, EFSA examined health claims related to green tea and concluded that "a cause and effect relationship has not been established between the consumption of catechins (including EGCG) from green tea … and contribution to the maintenance or achievement of a normal body weight" . Their results suggest that green tea catechins alone do not affect body weight or other anthropometric measurements. At the end of the study, glucomannan produced significantly greater weight loss (mean loss of 2.5 kg) than placebo (mean gain of 0.7 kg). The adverse effects of chitosan are minor and primarily involve the gastrointestinal tract. Rarer side effects include muscle weakness in patients with uremia and seizures in those with seizure disorders. Humans synthesize carnitine from its constituent amino acids, so dietary carnitine intake is not necessary. Carnitine is naturally present in animal products such as meat, fish, poultry, and milk and dairy products; small amounts are present in some plant foods. Furthermore, many weight-loss supplements contain multiple ingredients that have not been adequately tested in combination with one another. In some cases, the active constituents of botanical or other ingredients promoted for weight loss are unknown or uncharacterized . However, the authors noted that the quality of the trials included in their review was poor, making it impossible to draw firm conclusions. Although obesity does not affect the skin’s capacity to synthesize vitamin D, greater amounts of subcutaneous fat sequester more of the vitamin and alter its release into the circulation. However, 25 of the 70 participants dropped out of the study, and results were reported for only the 45 participants who completed the study (i.e., the authors did not complete an intention-to-treat analysis). Another systematic review and meta-analysis included 15 randomized controlled trials, 6 of which examined the effects of caffeine (39–83 mg/day) with and without green tea catechins (576–690 mg/day) on anthropometric measurements. A 2012 Cochrane Review analyzed the results from 14 randomized controlled trials of green tea preparations in a total of 1,562 participants with overweight or obesity . The authors of a meta-analysis of six randomized controlled trials with a total of 98 participants found that caffeine alone or in combination with catechins significantly increases energy expenditure in a dose-dependent fashion compared with placebo . In humans, forskolin might increase the frequency of bowel movements and cause loose stools , but doses of 500 mg/day (standardized for 10% forskolin) for 12 weeks have not been reported to cause more serious adverse events 104,106,107. In a study in mice, Coleus forskohlii extract caused dose-dependent hepatotoxicity, but pure forskolin did not have this effect, suggesting that other component(s) of Coleus forskohlii extract might be responsible for the hepatotoxicity . Forskolin is purported to promote weight loss by enhancing lipolysis and reducing appetite 103,104, possibly by stimulating cyclic adenosine monophosphate (cAMP) production. Trial durations ranged from 8 weeks to 6 months, and doses of chromium picolinate were 200 to 1,000 mcg/day. Chitosan had no significant effect on fecal fat excretion in the women compared to the control group. Dairy products, in particular, might contain additional components that have even greater effects on body weight than their calcium content alone would suggest 60,64-67. Data from a 12-year prospective observational study provide some insight into the long-term association between caffeine intake and body weight . After 6 months, those in the treatment group lost significantly more weight (mean weight loss 5.3 kg) than those in the placebo group (2.6 kg) and had significantly greater body fat reduction. According to all of these reviews, longer term clinical trials with rigorous designs and large samples are needed to determine the value of bitter orange for weight loss. At the end of the study, participants taking the combination bitter orange product had a significantly greater reduction in percent body fat and fat mass and a greater increase in basal metabolic rate than those in the placebo and control groups. Most reported adverse effects are mild, including headache, difficulty sleeping, flatulence, and gas . However, because ingredients might not be standardized and many products contain proprietary blends of ingredients, the active compounds and their amounts might not be comparable among products . All of these factors can make it difficult to compare the results of one study with those of another. In other cases, studies supporting a given ingredient’s use are small, of short duration, and/or of poor quality, limiting the strength of the findings. People need to talk with their health care providers about the use of weight-loss dietary supplements to understand what is known—and not known—about these products. Like all dietary supplements, weight-loss supplements can have side effects and might interact with prescription and over-the-counter medications. No serious adverse effects of Phaseolus vulgaris have been reported in clinical trials, but no trials have lasted longer than 13 weeks. Participants who received 107 or 106 CFU/g milk of Lactobacillus gasseri experienced significant reductions in visceral fat area (mean reductions of 8.5% and 8.2%, respectively), BMI, waist and hip circumference, and body fat mass compared with the control group. Other research indicates that green tea polyphenols do not elevate liver enzymes or cause liver dysfunction when consumed by healthy men for 3 weeks at a dose of 714 mg/day . For green tea extract, most reported adverse effects are mild to moderate, and they include nausea, constipation, abdominal discomfort, and increased blood pressure . For example, supplementation with 1,500 mg/day calcium (from calcium carbonate) was investigated in 340 adults with overweight or obesity (BMI ≥25) with mean baseline calcium intakes of 878 mg/day (treatment group) and 887 mg/day (placebo group) . A 2014 randomized crossover trial in 15 healthy young men found that diets high in milk or cheese (supplying a total of 1,700 mg/day calcium) significantly increased fecal fat excretion compared to a control diet that supplied 500 mg calcium/day . Several studies have correlated higher calcium intakes with lower body weight or less weight gain over time 57-61. Messages like “lose weight without dieting or exercising” and “to lose weight, all you have to do is take this pill” that sound too good to be true usually are. The active compounds, which are in the plant's stem and account for about 1.32% of the plant’s weight, are the alkaloids ephedrine, pseudoephedrine, norephedrine, and norpseudoephedrine 227,228. Yohimbe should only be used under medical supervision because of its potential to produce serious adverse effects . Of these, 30% caused adverse effects deemed moderate or major, 3.2% required admission to a critical care unit, and one led to a death. Only one randomized controlled trial has examined the effects of a dietary supplement containing raspberry ketone on weight loss. In mice fed a high-fat diet, raspberry ketone supplementation reduced food intake and body weight compared to the same diet without raspberry ketone . In a double-blind, placebo-controlled trial, 26 men and women who were overweight (BMI ≥25) were given 6 g/day pyruvate or placebo for 6 weeks . Although some of these studies suggest that pyruvate decreases body weight and body fat, others do not. There is also increasing evidence in humans that green tea extract might cause liver damage, though the underlying mechanism is not well understood . Catechins combined with caffeine also significantly increase fat oxidation, but caffeine alone does not. This effect might be important for maintaining weight loss by helping counteract the decrease in metabolic rate that can occur during weight loss. In this study, 75 healthy men and women who were overweight (BMI 24–30) received one of five treatments daily for 12 weeks while maintaining their regular lifestyle and eating habits. Caffeine might also contribute to weight loss by increasing fat oxidation through sympathetic activation of the central nervous system and by increasing fluid loss 41,45. Some studies indicate that bitter orange and synephrine—as bitter orange extract or pure synephrine—raise blood pressure and heart rate, but other studies show that they do not have these effects 25-27,31,36-39. Many dietary supplements promoted for weight loss contain added caffeine or an herbal source—such as guarana (Paullinia cupana), kola (or cola) nut (Cola nitida), and yerba maté (Ilex paraguariensis)—that naturally contains caffeine. The authors of an earlier review of animal studies, clinical trials, physiologic studies, and case reports concluded that synephrine alkaloids have a “suggestion of some benefit to weight loss,” but the available data are very limited and cannot be considered conclusive . Participants taking the herbal supplement had a significant increase in mean body weight (1.13 kg) compared with those taking a placebo (0.09 kg) at the end of the study. Similarly, other trials have found that 3–10 g/day beta-glucans for 4–12 weeks does not have a significant effect on weight loss . Several human studies have examined the effects of green tea catechins on weight loss and weight maintenance. It has been suggested that green tea and its components might reduce body weight by increasing energy expenditure and fat oxidation, reducing lipogenesis, and decreasing fat absorption 41, . Green tea is present in some dietary supplements, frequently in the form of green tea extract. Yerba Maté (see section on caffeine above) For green tea extract, most reported adverse effects are mild to moderate, and they include nausea, constipation, abdominal discomfort, and increased blood pressure .Based on 34 of the liver damage case reports and animal pharmacological and toxicological information, the USP concluded that the consumption of green tea products "probably" caused 7 cases of liver damage and “possibly” caused 27 cases.Chromium picolinate supplementation reduced body weight by 1.1 kg more than placebo, but the amount of weight loss did not correlate with the dose of chromium picolinate.The authors concluded that daily doses of 137 to 1,000 mcg chromium for 8 to 26 weeks reduce body weight by 0.5 kg and percent body fat by 0.46%.Humans synthesize carnitine from its constituent amino acids, so dietary carnitine intake is not necessary.A meta-analysis of eight randomized, placebo-controlled clinical trials evaluated the effects of capsaicinoids on ad libitum energy intake in a total of 191 participants who had a normal body weight or were moderately overweight .Like the authors of the Cochrane Review, these authors noted that the effect is small and of "uncertain" clinical relevance.A product containing caffeine plus glucosyl hesperidin (G-hesperidin, a flavonone glycoside found mainly in citrus fruits) reduced abdominal fat and BMI in a clinical trial in Japan . FDA no longer permits the use of ephedrine alkaloids in dietary supplements because of safety concerns that are detailed below, but information is provided here in response to continued interest in this ingredient. A 2015 analysis determined that only 22% of 49 dietary supplements containing yohimbe or yohimbine listed the quantity of yohimbine on the product label . More recently, dietary supplements containing yohimbe accounted for 1,818 self-reports to U.S. poison control centers between 2000 and 2012 . The authors of a 2011 review of yohimbe concluded that no conclusive evidence indicates that yohimbe affects body weight or body mass . In humans, however, results of clinical trials that assessed the impact of probiotics on obesity-related endpoints have been inconsistent. For example, probiotic supplementation reduced body weight gain and fat accumulation in obese mice fed a high-fat diet . In a randomized controlled trial, 49 healthy women (mean BMI 25) age 18–50 years were randomized to receive Hoodia gordonii purified extract (2,220 mg/day in two divided doses taken 1 hour before breakfast and dinner) or placebo combined with an ad libitum diet for 15 days . Doses of guar gum ranged from 9 to 30 g/day for 3 weeks to 6 months; most participants followed their usual diet, and some received dietary advice. Guar gum is present in certain dietary supplements and is an ingredient in some food products, especially gluten-free baked goods, because it helps bind and thicken these products. Safety Compared to the placebo group, those receiving METABO lost significantly more body weight (mean loss of 1.9 kg vs. 0.4 kg for placebo) and fat mass.This anecdotal evidence, combined with results of a few animal studies indicating that hoodia reduces food intake , led to the widespread marketing of hoodia as a weight-loss supplement in the United States in the early 2000s.Like glucomannan, guar gum is purported to promote weight loss by acting as a bulking agent in the gut; delaying gastric emptying; increasing feelings of satiety; and, theoretically, decreasing appetite and food intake 16,174.FDA and the Federal Trade Commission (FTC) can also take regulatory actions against manufacturers that make unsubstantiated weight-loss claims about their products.FDA and the FTC warn consumers to beware of fraudulent claims about weight-loss dietary supplements 235,236.Decreased intracellular calcium concentrations, in turn, might increase fat breakdown and discourage fat accumulation in these cells .Weight-loss products marketed as dietary supplements are sometimes adulterated or tainted with prescription-drug ingredients; controlled substances; or untested/unstudied, pharmaceutically active ingredients that could be harmful . Those in the Phaseolus vulgaris group also experienced a significantly greater reduction in fat mass, adipose tissue thickness, and waist–hip–thigh circumference. Laboratory research indicates that Phaseolus vulgaris extract inhibits alpha-amylase activity, so experts have hypothesized that the plant interferes with the breakdown and absorption of carbohydrates in the gastrointestinal tract 16, . Despite the association between low vitamin D levels and obesity, scientific evidence does not support a cause-and-effect relationship. Vitamin D, which is fat soluble, is present in a few foods, such as fatty fish, cheese, egg yolks, and vitamin D-fortified milk. However, additional research on raspberry ketone is needed to better understand its safety and side effects. Other ingredients, such as caffeine and bitter orange, could have an additive effect if taken with other stimulants. A product represented as a dietary supplement that contains one or more drug ingredients, whether or not these ingredients are declared on the label, is considered an unapproved drug and is therefore subject to enforcement action by FDA. At best, products with claims like these do not live up to them, and, even worse, they could be dangerous. The peak rise in resting metabolic rate at baseline was significantly higher in participants taking the herbal supplement than those in the placebo group, but the difference was not significant at the end of the 8-week study.However, when the authors analyzed the six studies that were conducted outside of Japan (where study methodologies were less heterogeneous than in the Japanese studies), they found no statistically significant difference in weight loss for green tea compared to placebo.Although microbes are found throughout the human body, the vast majority inhabit the colon.On average, participants gained some weight during the study, but men who increased their caffeine intake during the 12 years of follow-up gained a mean of 0.43 kg less than those who decreased their caffeine consumption.A 2014 randomized crossover trial in 15 healthy young men found that diets high in milk or cheese (supplying a total of 1,700 mg/day calcium) significantly increased fecal fat excretion compared to a control diet that supplied 500 mg calcium/day .Lifestyle changes that promote weight loss might also improve mood and energy levels and lower the risk of heart disease, diabetes, and some cancers .Overall, consuming capsaicinoids significantly reduced energy intake by a mean of 74 kcal per meal; body weight was not assessed, so the impact of this calorie reduction on weight loss cannot be quantified. These condition commonly require extended or repeat hospitalization in the first days of life to correct. Thanks to close monitoring and supplementing until her milk came in, her baby never lost excessive weight and is now a happy, thriving exclusively breastfed baby. Allison closely monitored her newborn’s weight and supplemented when she started showing signs of hunger. For more information about building a healthy dietary pattern, refer to the Dietary Guidelines for Americans and the U.S. The best way to lose weight and keep it off is to follow a sensible approach that incorporates a healthy eating plan, reduced caloric intake, and moderate physical activity under the guidance of a heath care provider. Some weight-loss supplement labels do not declare the amount of caffeine in the product and only list the herbal ingredients. Instead, caffeine, other stimulants in multicomponent formulations, and other constituents of bitter orange or adulterants (such as m-synephrine, which is not naturally present in bitter orange) might be responsible for its observed effects. For example, a single dose of 900 mg bitter orange standardized to 6% (54 mg) synephrine significantly increased heart rate as well as systolic and diastolic blood pressure for up to 5 hours compared to placebo in 15 healthy men and women . However, many of the products with these effects contain multiple herbal ingredients, and the role of bitter orange in these adverse effects cannot be isolated. The authors noted that the weight gain might have occurred by chance because the trial was insufficiently powered to detect this small difference. Table 1 briefly summarizes the findings discussed in more detail in this fact sheet on the safety and efficacy of the most common ingredients of weight-loss dietary supplements. In some cases, evidence of their purported benefits consists of limited data from animal and laboratory studies, rather than data from human clinical trials. Like other dietary supplements, weight-loss supplements differ from over-the-counter or prescription medications in that FDA does not classify them as drugs. However, according to a large national survey, less than one-third of U.S. adults who use weight-loss dietary supplements discuss this use with a health care professional . Manufacturers market these products with various claims, including that these products reduce macronutrient absorption, appetite, body fat, and weight and increase metabolism and thermogenesis. For healthy adults, FDA and the European Food Safety Authority (EFSA) state that up to 400 mg/day caffeine does not pose safety concerns 51,52, whereas the American Medical Association recommends a limit of 500 mg/day . These findings indicate that the higher doses of caffeine might be responsible for the observed effects. The 75 mg caffeine plus G-hesperidin significantly reduced BMI by a mean of 0.56 versus 0.02 for placebo. The five treatments were placebo and four formulations of 0, 25, 50, or 75 mg caffeine plus 500 mg G-hesperidin. Bitter Orange (Citrus aurantium L.); zhi qiao FDA and the FTC warn consumers to beware of fraudulent claims about weight-loss dietary supplements 235,236. Although these reported adverse effects could not be linked with certainty to the use of ephedra-containing dietary supplements, FDA deemed the safety concerns serious enough to prohibit the sale of dietary supplements containing ephedrine alkaloids in 2004 . According to an analysis of calls to the California Poison Control System in 2006, 18% of calls reporting an adverse effect or toxicity potentially caused by dietary supplements involved products containing yohimbe . The author of a 2010 review of yohimbe reached similar conclusions, noting that results from small human trials of yohimbine for weight loss are contradictory and the evidence base is insufficient to support a weight loss claim for this compound . Vitamin D from both foods and dietary supplements is safe at recommended intakes of 600–800 IU/day for adults . Overall, consuming capsaicinoids significantly reduced energy intake by a mean of 74 kcal per meal; body weight was not assessed, so the impact of this calorie reduction on weight loss cannot be quantified. Most research on capsaicin and other capsaicinoids focuses on their effects on energy intake and appetite, rather than body weight. Compared to placebo, calcium supplementation for 2 years had no clinically significant effects on weight. In contrast, in a 28-day trial, chitosan (2 g/day divided into two equal doses) failed to reduce body weight compared to placebo in 28 women who were overweight and in 6 men who were overweight and who maintained their normal diet during the study . One clinical trial randomly assigned 59 women with overweight or obesity (BMI 27–40) to receive either chitosan (3 g/day divided between the two largest meals) or placebo for 8 weeks while continuing their normal dietary and exercise habits . A 2016 meta-analysis of 33 randomized trials and longitudinal studies lasting 12 weeks to 6 years found that calcium from foods or supplements had no overall effect on body weight . The authors noted that the results suggest that at least 2 mg capsaicinoids are needed to reduce calorie intake but that the studies were very heterogeneous. For example, protein and other components of dairy products might modulate appetite-regulating hormones . Decreased intracellular calcium concentrations, in turn, might increase fat breakdown and discourage fat accumulation in these cells . All participants also took part in a circuit-training exercise program and were counseled to consume 1,800 kcal/day. At the end of the trial, all groups lost weight and had a smaller waist circumference, but there were no significant differences between groups. FDA and the Federal Trade Commission (FTC) can also take regulatory actions against manufacturers that make unsubstantiated weight-loss claims about their products. Approximately 15% of U.S. adults have used a weight-loss dietary supplement at some point in their lives; more women report use (21%) than men (10%) . Furthermore, the product contained many ingredients in addition to raspberry ketone, making it impossible to determine the effects of raspberry ketone alone. Although it has been touted on the Internet and national television as an effective way to burn fat, little evidence exists to support this claim. Additional research is needed to better understand the safety and possible side effects of this compound. Pyruvate is also available as a dietary supplement, frequently in the form of calcium pyruvate. All participants received counseling to follow a 2,000 kcal/day diet and completed 45–60 minutes of circuit training three times per week.In this study, chitosan treatment reduced body weight (mean weight loss about 2.5 kg) compared to placebo (mean weight loss about 1 kg); the addition of ascorbic acid led to additional body weight reductions of about 1.5 kg compared to chitosan alone.Those in the Phaseolus vulgaris group also experienced a significantly greater reduction in fat mass, adipose tissue thickness, and waist–hip–thigh circumference.In contrast, in a 28-day trial, chitosan (2 g/day divided into two equal doses) failed to reduce body weight compared to placebo in 28 women who were overweight and in 6 men who were overweight and who maintained their normal diet during the study .Results from laboratory and animal studies suggest that fucoxanthin might promote weight loss by increasing resting energy expenditure and fatty acid oxidation as well as by suppressing adipocyte differentiation and lipid accumulation 125,126.Like other dietary supplements, weight-loss supplements differ from over-the-counter or prescription medications in that FDA does not classify them as drugs.In a clinical trial in 258 patients with uncontrolled type 2 diabetes, 2 g/day L-carnitine plus the pharmaceutical ingredient orlistat (360 mg/day) for 1 year significantly increased weight loss compared to orlistat alone .Check for possible interactions between medicines, supplements and foods before taking them together. Hexavalent chromium (chromium VI) is toxic and not found in food or dietary supplements. Some research indicates that these supplements might also reduce food intake, hunger levels, and fat cravings , although data on these effects are sparse. Researchers have hypothesized that chromium supplements increase lean muscle mass and promote fat loss, but study results have been equivocal 41,100. The effect of chitosan (3 g/day) with or without ascorbic acid (2 g/day) was evaluated in an 8-week study in women age 20–30 who were overweight and who followed their regular diet and exercise habits . Habitual use of caffeine however, leads to caffeine tolerance and a diminishment of these effects 41,43.The USP noted that problems are more likely when green tea extract is taken on an empty stomach and, therefore, advises taking green tea extracts with food to minimize the possible risk of liver damage.We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health.One 12-week clinical trial, for example, randomized 210 healthy adults age 35 to 60 years who had large amounts of visceral fat to consume 200 g/day fermented milk containing 107, 106, or 0 (control) colony-forming units (CFU) of Lactobacillus gasseri SBT2055 (LG2055) per gram of milk .Compared to placebo, Coleus forskohlii extract had no effect on body weight, appetite, caloric intake, or macronutrient intake.However, a double-blind, placebo-controlled trial in 23 women who were overweight (mean BMI 27.4) who followed their normal diets and participated in weight training and 30 minutes of walking three times per week had a different outcome . The most important ways we know that a child is receiving enough milk is by closely monitoring weight loss, preventing excessive weight loss, monitoring for hyperbilirubinemia, hypoglycemia and dehydration and ensuring that a newborn is satisfied by their feedings. A child who is developing excessive weight loss or losing weight rapidly will need assistance in receiving more milk, either breast milk or properly prepared formula. The American Academy of Pediatrics recommends no greater than 7% weight loss for all newborns. Protecting a newborn baby from excessive weight loss is one of the most important ways we can protect their health and brain. The CLA isomer t10,c12-CLA has also been reported to increase insulin resistance and glycemia in men with obesity and metabolic syndrome 110,124. CLA might adversely affect lipid profiles, although results from studies are inconsistent. However, whether CLA caused this toxicity cannot be definitively established because the products were not analyzed to rule out the presence of a contaminant. Most reported adverse effects are minor, consisting mainly of gastrointestinal disturbances, such as abdominal discomfort and pain, constipation, diarrhea, loose stools, nausea, vomiting, and dyspepsia 3,109,111,113,115,116. Conjugated linoleic acid (CLA) is a mixture of linoleic acid isomers containing conjugated double bonds that is present mainly in dairy products and beef. Additional research is needed to better understand the safety and side effects of both short- and long-term use. Although animal studies indicate that forskolin reduces food intake 103,105, research in humans is very limited and inconclusive. This increased cAMP production, in turn, is thought to activate lipase and promote the release of fatty acids from adipose tissue . Only a few clinical trials have examined the effects of green coffee bean extract on weight loss in humans, and all were of poor methodological quality.Overall, study participants who received carnitine supplements lost an average of 1.33 kg more weight than those who received a placebo.Adverse effects from clinical trials include watery stools, headache, weakness, nausea, vomiting, constipation, vertigo, and urticaria (hives) 99,100.However, the extent to which bitter orange and synephrine cause similar cardiovascular and central nervous system effects to epinephrine and norepinephrine (e.g., increased heart rate and blood pressure) is not clear 25-27.The authors of a Cochrane Review that included 13 trials examining the effect of chitosan on body weight found that chitosan, when taken for 4 weeks to 6 months, reduced body weight by a mean of 1.7 kg compared with placebo .No adverse effects have been found in rats at doses up to 2,500 mg/kg body weight per day , but its safety has not been rigorously studied in humans.Data from a 12-year prospective observational study provide some insight into the long-term association between caffeine intake and body weight . In mice, green coffee bean extract in combination with a high-fat diet significantly reduced body weight gain and fat mass 149,150. A 2011 review and meta-analysis of 12 randomized controlled trials with a total of 706 participants examined the effects of Garcinia cambogia on weight loss . Compared to the placebo group, those receiving Xanthigen lost significantly more body weight by the end of the trial (mean loss of 6.9 kg vs. 1.4 kg for placebo in participants with NAFLD; mean loss of 6.3 kg vs. 1.4 kg for placebo in those without NAFLD). In contrast, those in the placebo group did not lose a significant amount of body weight (0.09 kg) or body fat (0.1 kg) compared to baseline. A 2013 Cochrane Review analyzed the results from nine randomized controlled trials of chromium picolinate supplements in a total of 622 participants with overweight or obesity (BMI ≥25) . Only a few clinical trials have examined the effects of green coffee bean extract on weight loss in humans, and all were of poor methodological quality. In another study conducted in the United States, supplementation with glucomannan (3.9 g/day) for 4 weeks in 63 healthy men did not significantly reduce body weight compared with placebo . In a small study conducted in the United States, 20 women with obesity (weighing ≥20% more than ideal body weight) consumed 3 g/day glucomannan (1 g before each meal) or placebo for 8 weeks . In this study, Coleus forskohlii extract did not affect body weight, but it did significantly decrease mean body fat by about 4% compared with about 1% for placebo. The authors of a Cochrane Review that included 13 trials examining the effect of chitosan on body weight found that chitosan, when taken for 4 weeks to 6 months, reduced body weight by a mean of 1.7 kg compared with placebo . This product contained 2,000 mg of a proprietary blend of raspberry ketone, caffeine, bitter orange, ginger, garlic, cayenne, L-theanine, and pepper extract along with B-vitamins and chromium. However, the authors noted that the methodological quality of all trials is weak, preventing them from drawing firm conclusions. In the placebo group, these measurements did not change significantly compared to baseline. All participants received counseling to follow a 2,000 kcal/day diet and completed 45–60 minutes of circuit training three times per week. The many different genera of probiotics include Lactobacillus, Streptococcus, and Bifidobacterium, which all have widely varying effects in the body 188,189. At the end of the trial, the pyruvate group had significant decreases in body weight (mean loss of 1.2 kg), body fat, and percent body fat compared to baseline but no significant changes in lean body mass. Additional research is needed to understand the potential effects of probiotics on body fat, body weight, and obesity in humans. More recently, a randomized study in 44 adults with type 2 diabetes who followed their usual diet found that 10 g/day guar gum significantly reduced waist circumference after 4 and 6 weeks compared to baseline, but it did not affect weight loss . Supplement manufacturers are responsible for determining that their products are safe and their label claims are truthful and not misleading. Therefore, it is important to consider what is known—and not known—about each ingredient in any dietary supplement before using it. Our clinical information meets the standards set by the NHS in their Standard for Creating Health Content guidance.Read our editorial policy. On average, participants gained some weight during the study, but men who increased their caffeine intake during the 12 years of follow-up gained a mean of 0.43 kg less than those who decreased their caffeine consumption. At the end of the study, participants taking the herbal product lost a mean of 5.1 kg compared to 0.3 kg for those taking the placebo. The 50 or 75 mg caffeine plus G-hesperidin also significantly reduced abdominal fat compared to placebo, whereas the G-hesperidin alone or with only 25 mg caffeine did not significantly affect BMI or abdominal fat. A product containing caffeine plus glucosyl hesperidin (G-hesperidin, a flavonone glycoside found mainly in citrus fruits) reduced abdominal fat and BMI in a clinical trial in Japan . The authors of a 2012 review of 23 small human clinical studies involving a total of 360 participants concluded that synephrine increases resting metabolic rate and energy expenditure . The peak rise in resting metabolic rate at baseline was significantly higher in participants taking the herbal supplement than those in the placebo group, but the difference was not significant at the end of the 8-week study. Interpreting the results of these studies is complicated by the fact that bitter orange is almost always combined with other ingredients in weight-loss supplements. Several small human studies have examined whether bitter orange is effective for weight loss . Studies have examined the effects of Irvingia gabonensis on weight loss to only a limited extent in humans. Women receiving Garcinia cambogia lost significantly more weight (3.7 kg) than those receiving placebo (2.4 kg). CLA might also increase some markers of oxidative stress and decrease breastmilk fat levels, but additional research is needed to confirm these effects . However, the authors noted that the "magnitude of these effects is small, and the clinical relevance is uncertain." Participants received CLA as a free fatty acid (3.6 g CLA isomers), CLA as a triacylglycerol (3.4 g CLA isomers), or placebo daily for 1 year. Check for possible interactions between medicines, supplements and foods before taking them together. Common semaglutide side-effects (these affect fewer than 1 in 10 people) Very common semaglutide side-effects (these affect more than 1 in 10 people) Participants were counseled to eat a normal diet except for limiting dietary fat to 30% of calories and to exercise moderately. Habitual use of caffeine however, leads to caffeine tolerance and a diminishment of these effects 41,43. A 100 mg dose of caffeine, for example, increased energy expenditure by a mean of 9.2 kcal/hr more than placebo in healthy humans, and this effect lasted for 3 hours or more. Very little research has been conducted on the use of yohimbe for weight loss and/or its effect on body mass. Overall, the available research suggests that consuming higher amounts of vitamin D or taking vitamin D supplements does not promote weight loss. It is also available in many dietary supplements, and humans synthesize it naturally when their skin is exposed to sunlight. Doses contained in dietary supplements typically range from 100 to 1,400 mg, and the safety of such doses has never been evaluated in humans . During the 8-week study, participants followed a calorie-restricted diet (approximately 500 calories less per day than estimated needs) and engaged in moderate exercise (60 minutes 3 days per week). This anecdotal evidence, combined with results of a few animal studies indicating that hoodia reduces food intake , led to the widespread marketing of hoodia as a weight-loss supplement in the United States in the early 2000s. Like glucomannan, guar gum is purported to promote weight loss by acting as a bulking agent in the gut; delaying gastric emptying; increasing feelings of satiety; and, theoretically, decreasing appetite and food intake 16,174. The USP noted that problems are more likely when green tea extract is taken on an empty stomach and, therefore, advises taking green tea extracts with food to minimize the possible risk of liver damage. Based on 34 of the liver damage case reports and animal pharmacological and toxicological information, the USP concluded that the consumption of green tea products "probably" caused 7 cases of liver damage and “possibly” caused 27 cases. Consumption of some green tea extracts—primarily ethanolic extracts of green tea—has also been linked to liver damage in at least 50 case reports since 2006 43,172. They concluded that chitosan appears to be more effective than placebo for short-term weight loss, but most studies have been of poor quality. It is purported to promote weight loss by binding to some dietary fat in the digestive tract, preventing its absorption 16,41. Studies have primarily evaluated carnitine’s effects on lipid levels, cardiovascular disease, and type 2 diabetes; weight loss has been a secondary outcome in most studies. However, the calorie reductions did not significantly affect body weight at either 6 weeks or 12 weeks. At the end of the trial, participants receiving 4 mg/day capsaicinoids reported a mean intake of 252 fewer calories per day than those receiving placebo and a mean of 140 fewer calories per day than those receiving 2 mg/day capsaicinoids. Irvingia gabonensis seed kernel extract has been proposed to promote weight loss by inhibiting adipogenesis, as demonstrated in vitro . Furthermore, dosages and amounts of active components vary widely among weight-loss supplements, and a product’s composition is not always fully described in published studies . FDA does not permit dietary supplements to contain pharmaceutical ingredients, and manufacturers may not promote dietary supplements to diagnose, treat, cure, or prevent any disease . People who are considering using weight-loss supplements should talk with their health care provider to discuss these products' potential benefits and risks. Taken together, these results indicate that the effects of probiotics on body weight and obesity might depend on several factors, including the probiotic strain, dose, and duration as well as certain characteristics of the user, including age, sex, and baseline body weight. Compared to placebo, hoodia extract had no significant effect on energy intake or body weight. Other researchers and medical experts advise using dietary supplements containing green tea extract only with caution . The trials lasted from 12 to 13 weeks, and doses of green tea catechins ranged from 141 to 1,207 mg; in 10 of the 14 trials, the green tea preparations contained caffeine.