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Show references AskMayoExpert. Weight management adult. Mayo Clinic; Obesity adult. Pilitsi E, et al. Pharmacotherapy of obesity: Available medications and drugs under investigation. Perreault L.

Obesity in adults: Drug therapy. Accessed Oct. Prescription medications to treat overweight and obesity. National Institute of Diabetes and Digestive and Kidney Diseases. Accessed Aug.

Melmed S, et al. In: Williams Textbook of Endocrinology. Elsevier; Patel K. Obesity treatment: A focus on pharmacotherapy of weight management.

Papadakis MA, et al. McGraw Hill; Shah M expert opinion. Mayo Clinic. Apovian CM, et al. Pharmacological management of obesity: An Endocrine Society clinical practice guideline.

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Blink Smart Security for Every Home. Amazon Subscription Boxes Top subscription boxes — right to your door. PillPack Pharmacy Simplified. Amazon Renewed Like-new products you can trust. 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 [ 74 ].

Overall, the results from clinical trials do not support a clear link between higher calcium intakes and lower body weight, prevention of weight gain, or weight loss. High intakes of calcium can cause constipation and might interfere with the absorption of iron and zinc, although this effect is not well established.

High intakes of calcium from supplements, but not foods, have been associated with an increased risk of kidney stones [ 56 , ]. Capsaicinoids give chili peppers their characteristic pungent flavor. Capsaicin is the most abundant and well-studied capsaicinoid [ 78 ].

Capsaicin and other capsaicinoids have been proposed to have anti-obesity effects via their ability to increase energy expenditure and lipid oxidation, attenuate postprandial insulin response, increase satiety, and reduce appetite and energy intake [ ].

Other research suggests that capsaicin increases satiety by inducing gastrointestinal distress e. Most research on capsaicin and other capsaicinoids focuses on their effects on energy intake and appetite, rather than body weight.

A meta-analysis of eight randomized, placebo-controlled clinical trials evaluated the effects of capsaicinoids on ad libitum energy intake in a total of participants who had a normal body weight or were moderately overweight [ 78 ].

Doses of capsaicinoids ranged from 0. 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. 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.

However, the calorie reductions did not significantly affect body weight at either 6 weeks or 12 weeks. It might also increase serum insulin and reduce high-density lipoprotein HDL cholesterol levels. Otherwise, capsaicin and other capsaicinoids appear to be safe.

Research is underway to reduce the pungency and chili taste associated with capsaicin while retaining its potential biological effects [ 81 ]. Carnitine is the generic term for several compounds, including L-carnitine itself, several acylcarnitines e.

It is composed of the amino acids lysine and methionine [ 84 ]. 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. Humans synthesize carnitine from its constituent amino acids, so dietary carnitine intake is not necessary.

Almost all cells of the body contain carnitine, which transports fatty acids into the mitochondria and acts as a cofactor for fatty acid beta-oxidation [ 85 ]. Because of these effects, carnitine has been proposed as a weight-loss agent.

A systematic review and meta-analysis combined the results from nine carnitine supplementation clinical trials in adults including the two described above that assessed weight loss [ 85 ]. The trials included a total of participants.

In eight trials, the daily carnitine doses ranged from 1. Overall, study participants who received carnitine supplements lost an average of 1. Additional research on carnitine for weight loss is warranted.

Rarer side effects include muscle weakness in patients with uremia and seizures in those with seizure disorders. Some research indicates that intestinal bacteria metabolize carnitine to form trimethylamine N-oxide TMAO , a substance that might increase the risk of cardiovascular disease [ 91 ].

This effect appears to be more pronounced in people who consume meat than in vegans or vegetarians. The implications of this effect are not well understood and require more research.

Chitosan is a manufactured polysaccharide that is commercially prepared from the exoskeletons of crustaceans. It is purported to promote weight loss by binding to some dietary fat in the digestive tract, preventing its absorption [ 16 , 41 ].

Chitosan might also decrease cholesterol absorption [ 16 ]. Chitosan capsules taken before meals total of 2. However, the amount of fat that the chitosan trapped would result in a loss of only 1 lb body fat over about 7 months.

Chitosan had no significant effect on fecal fat excretion in the women compared to the control group. At the end of the study, those in the treatment group lost a mean of 1 kg body weight compared to a mean weight gain of 1.

In this study, chitosan treatment reduced body weight mean weight loss about 2. 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.

They concluded that chitosan appears to be more effective than placebo for short-term weight loss, but most studies have been of poor quality. The authors also noted that results from high-quality trials indicate that chitosan has minimal effects on body weight, and these effects are probably clinically insignificant.

The adverse effects of chitosan are minor and primarily involve the gastrointestinal tract. They include flatulence, bloating, mild nausea, constipation, indigestion, and heartburn [ 93 , 95 , 96 ]. Because chitosan is derived from shellfish, people who are allergic to shellfish could theoretically be allergic to chitosan [ 97 ].

The trivalent form of chromium chromium III is an essential trace mineral that potentiates the action of insulin. Dietary supplements commonly contain chromium in the form of chromium picolinate, which consists of chromium and picolinic acid, although they might also contain other forms, including chromium nicotinate and chromium yeast [ 99 ].

Poor chromium status might contribute to impaired glucose tolerance and type 2 diabetes [ 98 ]. Researchers have hypothesized that chromium supplements increase lean muscle mass and promote fat loss, but study results have been equivocal [ 41 , ].

Some research indicates that these supplements might also reduce food intake, hunger levels, and fat cravings [ ], although data on these effects are sparse. Several studies have evaluated the effects of chromium supplements, usually in the form of chromium picolinate, on weight loss.

Six of the trials included resistance or weight training, and three did not. Chromium picolinate supplementation reduced body weight by 1. Also in , 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 individuals with overweight or obesity [ 99 ].

The authors concluded that daily doses of to 1, mcg chromium for 8 to 26 weeks reduce body weight by 0. Like the authors of the Cochrane Review, these authors noted that the effect is small and of "uncertain" clinical relevance.

Similar findings were reported from an earlier meta-analysis of 12 trials [ ]. Trivalent chromium appears to be well tolerated. Adverse effects from clinical trials include watery stools, headache, weakness, nausea, vomiting, constipation, vertigo, and urticaria hives [ 99 , ].

Chromium does not have an established UL because few serious adverse effects have been linked to high intakes [ 98 ]. Hexavalent chromium chromium VI is toxic and not found in food or dietary supplements.

Forskolin is a compound isolated from the roots of Coleus forskohlii , a plant that grows in subtropical areas, such as India and Thailand. Forskolin is purported to promote weight loss by enhancing lipolysis and reducing appetite [ , ], possibly by stimulating cyclic adenosine monophosphate cAMP production.

This increased cAMP production, in turn, is thought to activate lipase and promote the release of fatty acids from adipose tissue [ 16 ]. Although animal studies indicate that forskolin reduces food intake [ , ], research in humans is very limited and inconclusive.

Compared to placebo, Coleus forskohlii extract had no effect on body weight, appetite, caloric intake, or macronutrient intake. 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 has not been evaluated in longer term trials. Additional research is needed to better understand the safety and side effects of both short- and long-term use.

Conjugated linoleic acid CLA is a mixture of linoleic acid isomers containing conjugated double bonds that is present mainly in dairy products and beef. The various isomeric forms of CLA include c9,tCLA and t10,cCLA, and it is available in dietary supplements as a triacylglycerol or as a free fatty acid [ ].

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 , ]. Although CLA appears to reduce body fat mass in animals [ 17 ], results from human studies suggest that its effects are small and of questionable clinical relevance [ ].

One double-blind, placebo-controlled trial evaluated the effects of CLA supplementation as a mixture of c9,tCLA and t10,cCLA in male and female volunteers who were overweight BMI 25—30 consuming an ad libitum diet [ ].

Participants received CLA as a free fatty acid 3. At the end of the study, body fat mass dropped by significant amounts with both forms of CLA compared with placebo; reductions, on average, were 6. Supplementation with CLA as a free fatty acid but not as a triacylglycerol also increased lean body mass compared with placebo.

In another double-blind crossover trial, daily supplementation with CLA oil 6. These findings are similar to those from a randomized, double-blind, placebo- controlled trial in 63 adults with overweight or obesity BMI 24—35 that found statistically significant, but small, reductions in mean weight 0.

In contrast, those in the placebo group did not lose a significant amount of body weight 0. However, 3. The authors of a systematic review and meta-analysis of seven randomized controlled trials concluded that taking 2. However, the authors noted that the "magnitude of these effects is small, and the clinical relevance is uncertain.

CLA appears to be well tolerated. 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 , , , , , ].

CLA might also increase some markers of oxidative stress and decrease breastmilk fat levels, but additional research is needed to confirm these effects [ ].

CLA has been linked to hepatitis in three case reports [ ]. However, whether CLA caused this toxicity cannot be definitively established because the products were not analyzed to rule out the presence of a contaminant. CLA might adversely affect lipid profiles, although results from studies are inconsistent.

Some research indicates that CLA has no major effect on lipid profiles, but other research shows that certain CLA isomers might decrease HDL cholesterol and increase lipoprotein a levels [ , , , ]. The CLA isomer t10,cCLA has also been reported to increase insulin resistance and glycemia in men with obesity and metabolic syndrome [ , ].

Fucoxanthin is a carotenoid in brown seaweed and other algae. 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 [ , ].

Only one clinical trial has been conducted on the possible weight-loss effects of fucoxanthin. This week trial used Xanthigen, a dietary supplement containing brown seaweed extract and pomegranate-seed oil [ ]. Compared to the placebo group, those receiving Xanthigen lost significantly more body weight by the end of the trial mean loss of 6.

The safety of fucoxanthin has not been thoroughly evaluated in humans. Although participants using Xanthigen in the clinical trial described above reported no adverse effects [ ], further investigation of the safety and potential side effects of fucoxanthin at various levels of intake is required.

Garcinia cambogia is a fruit-bearing tree that grows throughout Asia, Africa, and the Polynesian islands [ ]. The pulp and rind of its fruit contain high amounts of hydroxycitric acid HCA , a compound that has been proposed to inhibit lipogenesis, increase hepatic glycogen synthesis, suppress food intake, and reduce weight gain [ 6 , 15 , , , ].

Studies in rats have found that Garcinia cambogia suppresses food intake and inhibits weight gain [ 3 ]. 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 , ].

In one randomized, placebo-controlled trial, 89 women who were mildly overweight mean BMI Women receiving Garcinia cambogia lost significantly more weight 3. However, Garcinia cambogia did not alter appetite, and the study produced no evidence that the supplement affected feelings of satiety.

Participants in both groups lost weight, but the between-group weight-loss differences were not statistically significant. HCA also had no effect on body fat loss. A review and meta-analysis of 12 randomized controlled trials with a total of participants examined the effects of Garcinia cambogia on weight loss [ ].

Therefore, the effect of Garcinia cambogia on body weight remains uncertain. The reported adverse effects of Garcinia cambogia and HCA are generally mild and include headache, nausea, upper respiratory tract symptoms, and gastrointestinal symptoms [ , , ].

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 [ ]. Symptoms included grandiosity an unrealistic sense of superiority , irritability, pressured speech, and decreased need for sleep.

Reports have also described 10 cases of liver toxicity, resulting in one death and two liver transplants, in people taking products containing Garcinia cambogia [ 43 , ].

In most of these cases, the products contained other botanical ingredients and minerals as well, so the toxicity cannot be definitively attributed to Garcinia cambogia. Because all clinical trials of Garcinia cambogia and HCA have been short, its long-term safety is unknown.

Glucomannan is a soluble dietary fiber derived from konjac root Amorphophallus konjac that can absorb up to 50 times its weight in water [ 16 ]. Like guar gum, glucomannan has been proposed to increase feelings of satiety and fullness and prolong gastric emptying by absorbing water in the gastrointestinal tract [ 16 , , ].

It might also reduce fat and protein absorption in the gut [ 16 ]. Glucomannan appears to have beneficial effects on blood lipids and glucose levels [ ], but its effects on weight loss are inconsistent.

At the end of the study, glucomannan produced significantly greater weight loss mean loss of 2. In another study conducted in the United States, supplementation with glucomannan 3.

Eight weeks of glucomannan supplementation 1. The authors of a systematic review of six randomized controlled trials with a total of participants concluded that 1.

Similarly, a meta-analysis of eight trials that included participants found that glucomannan did not significantly affect weight loss compared to placebo [ ].

The authors of an older meta-analysis of 14 studies designed primarily to investigate glucomannan's effect on lipid and blood glucose levels concluded that 1. Little is known about the long-term safety of glucomannan.

Glucomannan appears to be well tolerated for short-term use, with minor adverse effects, including belching, bloating, loose stools, flatulence, diarrhea, constipation, and abdominal discomfort [ , , , ].

The use of tablet forms of glucomannan was reported to be associated with seven cases of esophageal obstruction in — in Australia [ 99 ]. Users should therefore be cautious when taking glucomannan tablets.

Powdered and capsule forms have not been associated with this effect [ ]. The seeds or beans of the coffee plant Coffea arabica, Coffea canephora, Coffea robusta are green until they are roasted. Compared to roasted beans, green coffee beans have higher levels of chlorogenic acid.

Green coffee extract, probably because of its chlorogenic acid content, inhibits fat accumulation in mice and humans by regulating adipogenesis. Green coffee extract also modulates glucose metabolism [ ], perhaps by reducing glucose absorption in the gut [ ].

Green coffee beans contain caffeine see section on caffeine above [ ], although decaffeinated forms are available [ 16 ]. In mice, green coffee bean extract in combination with a high-fat diet significantly reduced body weight gain and fat mass [ , ]. 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.

The researchers concluded that green coffee bean extract has a moderate but significant effect on body weight mean weight loss of 2. The authors of another small clinical trial claimed to show a benefit of green coffee bean extract for weight loss [ ], but the study was strongly criticized by the FTC for having several critical flaws in its design [ , ].

Two of the three study authors subsequently retracted the journal publication. Green coffee bean extract appears to be well tolerated, but its safety has not been rigorously studied. Reported adverse effects include headaches and urinary tract infections [ ].

The caffeine naturally present in green coffee beans acts as a stimulant and can cause adverse effects, depending on the dose and whether it is combined with other stimulants see section on caffeine above. Green tea Camellia sinensis is a popular beverage consumed worldwide that has several purported health benefits [ ].

Green tea is present in some dietary supplements, frequently in the form of green tea extract. The active components of green tea that are associated with weight loss are caffeine see section on caffeine above and catechins, primarily epigallocatechin gallate EGCG , which is a flavonoid [ 41 , ].

A typical brewed cup of green tea has about — mg catechins [ ] and 45 mg caffeine. 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 might also decrease carbohydrate digestion and absorption [ ]. Available green tea extracts cover the range from minimally processed tea leaves to highly processed, manufactured concentrates of single constituents, such as EGCG.

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 [ ].

This effect might be important for maintaining weight loss by helping counteract the decrease in metabolic rate that can occur during weight loss. Catechins combined with caffeine also significantly increase fat oxidation, but caffeine alone does not. Other human research indicates that EGCG alone does not increase resting metabolic rate, fat oxidation, or the thermic effect of feeding the increase in metabolic rate associated with the digestion and absorption of food [ , ].

Taken together, these findings suggest that green tea catechins and caffeine might act synergistically [ 41 , , ]. Several human studies have examined the effects of green tea catechins on weight loss and weight maintenance.

A Cochrane Review analyzed the results from 14 randomized controlled trials of green tea preparations in a total of 1, participants with overweight or obesity [ ].

The trials lasted from 12 to 13 weeks, and doses of green tea catechins ranged from to 1, mg; in 10 of the 14 trials, the green tea preparations contained caffeine.

Green tea supplementation reduced body weight by a mean of 0. 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.

The authors reported that green tea catechins combined with caffeine over a median of 12 weeks modestly yet significantly reduced body weight by a mean of 1.

Only two studies in this meta-analysis examined the effects of green tea catechins alone. Their results suggest that green tea catechins alone do not affect body weight or other anthropometric measurements.

A meta-analysis of 11 randomized controlled trials found that people who took EGCG combined with caffeine for 12—13 weeks lost a mean of 1. In , 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" [ ].

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 [ , ]. No adverse effects have been reported from the consumption of green tea as a beverage [ ].

For green tea extract, most reported adverse effects are mild to moderate, and they include nausea, constipation, abdominal discomfort, and increased blood pressure [ ]. 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 [ ].

Other evidence in mice shows that high doses of catechins cause liver toxicity. There is also increasing evidence in humans that green tea extract might cause liver damage, though the underlying mechanism is not well understood [ ].

An analysis of 1, postmenopausal women participating in the Minnesota Green Tea Trial found that women who consumed green tea extract containing 1, mg total catechins including mg EGCG and 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 [ 43 , ].

In , the U. Pharmacopeia USP systematically reviewed the safety of green tea products [ ]. 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.

Other researchers and medical experts advise using dietary supplements containing green tea extract only with caution [ ]. Guar gum is a soluble dietary fiber derived from seeds of the Indian cluster bean Cyamopsis tetragonolobus [ 16 , ].

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. 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 , ].

However, guar gum does not appear to enhance weight loss. In a meta-analysis of 20 randomized, double-blind, placebo-controlled trials that statistically pooled data from 11 trials, Pittler and colleagues evaluated the effects of guar gum for body weight reduction in a total of adults [ ].

Trial participants included people with hypercholesterolemia, hyperlipidemia, or type 1 or type 2 diabetes; menopausal women; and healthy volunteers.

Compared with placebo, guar gum had no significant effect on weight loss. The authors concluded that guar gum is not effective for body weight reduction.

Reported adverse effects for guar gum are primarily gastrointestinal and include abdominal pain, flatulence, diarrhea, increased number of bowel movements, nausea, and cramps [ , , ]. Case reports indicate that guar gum can cause severe esophageal and small-bowel obstruction if taken without sufficient fluid [ , ].

However, these reports were about a guar gum product that is no longer available [ ]. In their meta-analysis, Pittler and colleagues concluded that given the adverse effects associated with the use of guar gum, the risks of taking it outweigh its benefits [ ].

Hoodia gordonii is a succulent plant that grows in the Kalahari Desert of southern Africa. The San people have traditionally used hoodia as an appetite suppressant during long hunts.

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 s.

Scientists have not determined the exact mechanism whereby hoodia might suppress appetite. A glycoside commonly called P57, which may have central nervous system activity [ ], is widely believed to be the main active ingredient, although not all researchers agree [ 16 , ].

Despite its popularity as a weight-loss supplement, very little scientific research on hoodia has been conducted in humans [ ]. Compared to placebo, hoodia extract had no significant effect on energy intake or body weight. Hoodia has been reported to cause significant increases in heart rate and blood pressure [ ].

It also raises bilirubin and alkaline phosphatase levels which may indicate impaired liver function , although the clinical significance of these findings is unclear because hoodia has not been reported to affect levels of other liver enzymes.

Other side effects include headache, dizziness, nausea, and vomiting. In the past, some hoodia products were found to contain little or no hoodia [ ].

The human microbiota, which outnumber human cells by up to fold, have myriad roles in human health [ , ]. Although microbes are found throughout the human body, the vast majority inhabit the colon.

The gut microbiota play an important role in nutrient and energy extraction from food. Research in mice suggests that the gut microbiota affect not only use of energy from the diet but also energy expenditure and storage within the host [ ].

Whether these effects translate to humans is unknown. 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. Probiotics are in foods, such as some yogurts, as well as dietary supplements.

The many different genera of probiotics include Lactobacillus, Streptococcus, and Bifidobacterium, which all have widely varying effects in the body [ , ].

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.

For example, probiotic supplementation reduced body weight gain and fat accumulation in obese mice fed a high-fat diet [ ]. In humans, however, results of clinical trials that assessed the impact of probiotics on obesity-related endpoints have been inconsistent.

In another randomized clinical trial, daily supplementation with 3. However, among the 77 female participants, the Lactobacillus supplementation did significantly reduce body weight after 12 weeks loss of 1. Another recent systematic review and meta-analysis of 15 randomized controlled trials in individuals with overweight or obesity found that supplementation with various doses and strains of probiotics for 3 to 12 weeks resulted in larger reductions in body weight by 0.

However, these effects were small and of questionable clinical significance. The most recent systematic review and meta-analysis, which included 19 randomized trials in 1, participants, found that supplementation with probiotics or synbiotics products containing both probiotic organisms and prebiotic sugars, which microorganisms in the gastrointestinal tract use as metabolic fuel reduced waist circumference slightly by 0.

The findings from another meta-analysis of 14 trials in adults, 5 trials in children, and 12 trials in 1, infants suggested that probiotics promote an average loss of 0. 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.

Additional research is needed to understand the potential effects of probiotics on body fat, body weight, and obesity in humans. Many probiotic strains derive from species with a long history of safe use in foods or from microorganisms that colonize healthy gastrointestinal tracts.

For these reasons, the common probiotic species—such as Lactobacillus species acidophilus, casei, fermentum, gasseri, johnsonii, paracasei, plantarum, rhamnosus, and salivarius and Bifidobacterium species adolescentis, animalis, bifidum, breve, and longum —are unlikely to cause harm [ ].

Side effects of probiotics are usually minor and consist of self-limited gastrointestinal symptoms, such as gas. In a few cases, mainly involving individuals who were severely ill or immunocompromised, the use of probiotics has been linked to bacteremia, fungemia fungi in the blood , or infections that result in severe illness [ , ].

For individuals with compromised immune function or other serious underlying diseases, the World Gastroenterology Organisation advises restricting probiotic use to the strains and indications that have proven efficacy [ ]. Pyruvate is a three-carbon compound that is generated in the body through glycolysis [ ].

Pyruvate is also available as a dietary supplement, frequently in the form of calcium pyruvate. Researchers have suggested that pyruvate enhances exercise performance and reduces body weight and body fat, possibly by increasing lipolysis and energy expenditure [ 6 , , ].

Only a few studies have examined the effects of pyruvate supplementation in humans. Although some of these studies suggest that pyruvate decreases body weight and body fat, others do not. At the end of the trial, the pyruvate group had significant decreases in body weight mean loss of 1.

In the placebo group, these measurements did not change significantly compared to baseline. However, a double-blind, placebo-controlled trial in 23 women who were overweight mean BMI The authors of a systematic review and meta-analysis of six randomized controlled trials in a total of participants concluded that 5—30 g pyruvate for 3—6 weeks reduces body weight by a mean of 0.

However, the authors noted that the methodological quality of all trials is weak, preventing them from drawing firm conclusions. The safety of pyruvate has not been rigorously studied. Pyruvate might also increase LDL levels and decrease HDL levels [ , ]. Additional research is needed to better understand the safety and possible side effects of this compound.

Raspberry ketone is the primary aroma compound found in red raspberries Rubus idaeus , and it is added to some foods as a flavoring agent [ 16 , ]. In vitro and animal studies suggest that raspberry ketone might help prevent weight gain by increasing fatty acid oxidation, suppressing lipid accumulation, and inhibiting pancreatic lipase activity [ 16 ].

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.

In mice fed a high-fat diet, raspberry ketone supplementation reduced food intake and body weight compared to the same diet without raspberry ketone [ ]. Only one randomized controlled trial has examined the effects of a dietary supplement containing raspberry ketone on weight loss.

This product contained 2, 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.

During the 8-week study, participants followed a calorie-restricted diet approximately calories less per day than estimated needs and engaged in moderate exercise 60 minutes 3 days per week. Compared to the placebo group, those receiving METABO lost significantly more body weight mean loss of 1.

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. Furthermore, the product contained many ingredients in addition to raspberry ketone, making it impossible to determine the effects of raspberry ketone alone.

Typical diets provide only a few mg of raspberry ketone a day. Doses contained in dietary supplements typically range from to 1, mg, and the safety of such doses has never been evaluated in humans [ ].

Participants in the METABO study described above had no serious adverse effects [ ]. However, additional research on raspberry ketone is needed to better understand its safety and side effects. Vitamin D, which is fat soluble, is present in a few foods, such as fatty fish, cheese, egg yolks, and vitamin D-fortified milk.

It is also available in many dietary supplements, and humans synthesize it naturally when their skin is exposed to sunlight. Vitamin D promotes calcium absorption in the gastrointestinal tract and is needed for proper bone growth and remodeling [ 56 ].

Observational studies indicate that greater body weights are associated with lower vitamin D status, and individuals with obesity frequently have marginal or deficient circulating levels of vitamin D [ ].