Some sources suggest that weight loss supplements are a $37 billion industry estimated to grow to $125 billion in the next 10 years. These products claim to burn fat, speed up your metabolism, decrease your appetite, and ultimately shed pounds.
While there are a few exceptions, most of the evidence on supplements for weight loss doesn’t support this story. Even studies that show statistically significant weight loss don’t often show clinically significant weight loss, meaning the amount lost is minimal.Weight loss is most effective when guided by your healthcare provider and a registered dietitian nutritionist (RD or RDN).
1. Fiber
Fiber is known to slow digestion and can support satiety. Some studies have shown that high-fiber diets and fiber supplements can help weight loss, though others have shown no benefit, such as:
- Supplements may not offer the same benefits as food: Studies suggest soluble fiber (fiber that forms a gel) supplements have mixed results on total calories consumed. While supplements have the potential to increase a satisfied feeling of fullness and decrease total calories eaten, more research is needed to understand the best types and dosages.
- The type of fiber matters: Soluble fiber may slow digestion and increase satiety, which could facilitate weight loss. One large analysis suggests that guar gum has the greatest potential for decreasing energy intake, but results have been mixed.
- A calorie deficit is still required: Fiber supplements may help weight loss paired with energy restriction. Because fiber can support satiety, some people may be able to maintain a calorie deficit to facilitate weight loss.
It’s recommended that adults consume 25 to 35 grams of fiber per day. It’s best to get fiber from food such as whole grains, fruits, vegetables, and legumes, which also offer other health benefits. However, if you cannot get enough fiber through your diet, a fiber supplement—when paired with a balanced diet and exercise—may help with weight loss.
2. Calcium and Vitamin D
It’s been hypothesized that vitamin D and calcium supplements may facilitate weight loss. However, there is insufficient evidence to support this theory.
- Vitamin D: Low vitamin D levels have been associated with higher body fat levels. Researchers have looked at whether vitamin D supplements may lead to weight loss. While some studies have shown very small amounts of weight loss (1 to 2 kilograms) when paired with a calorie deficit, other research suggests no benefit. The National Institutes of Health (NIH) concludes that vitamin D does not help people lose weight.
- Calcium: It’s thought that calcium may positively impact fat metabolism, which may lead to less fat storage or, potentially, even fat loss. Calcium and vitamin D together may support weight loss in specific populations.. However, conflicting research exists.
There isn’t enough evidence to back the benefits of vitamin D or calcium supplements for weight loss for everyone. However, it’s essential to ensure you are consuming adequate amounts of both for overall health.
3. Probiotics
Emerging research suggests a more diverse gut microbiome (gut bacteria) is associated with lower weight, as follows:
- Probiotics can help you maintain a diverse gut microbiome. However, much is still unknown about the most important strains and the benefits of consuming supplements rather than eating probiotic-rich food.
- Data show minimal benefit to taking probiotics for weight loss. Some studies have shown that supplements may lead to relatively insignificant weight loss (less than 1 pound).
More research is needed to understand the potential benefits of probiotic supplements for weight loss and, if there is a benefit, which strains and doses of probiotics are recommended. Prioritize foods and drinks rich in probiotics, such as yogurt, kefir, kimchi, sauerkraut, and kombucha, to support a diverse microbiome.
4. Iron
Iron status and weight may be related, but more research is needed to understand how this relationship works and whether iron supplements help with weight management.
- Iron deficiency is associated with obesity: Observational studies suggest a connection between higher body weight and iron deficiency. This could be due to how iron is metabolized, related to diet and access to iron-rich foods, or other factors such as inflammation that could impact iron levels.Some small studies suggest weight loss may support better iron levels, but more research is needed.
- Iron deficiency can cause fatigue: Fatigue is a common symptom of iron deficiency anemia, which can cause people to become less active. Since exercise is an integral part of weight management, there could be an indirect link between low iron and weight.
There is a lack of substantial evidence in humans to suggest that iron supplementation helps with weight loss. However, if you’re deficient in iron, it’s recommended to prioritize iron-rich foods and consider supplements to ensure adequate levels.
5. Protein
Protein plays a role in appetite regulation and muscle growth and maintenance, both of which can support weight loss, as follows:
- Protein helps you feel full: Protein supports fullness by slowing digestion and impacting hunger hormones. High-protein diets have been shown to support satiety and weight loss in the short term, though more studies are needed to understand their sustainability and impact on weight beyond 12 months.
- Protein helps build muscle mass: When paired with resistance training, protein can help you maintain and even build muscle mass. Maintaining muscle mass is essential to supporting your metabolism, which may help with weight loss and maintenance.
- High-protein diets may support weight loss or prevent weight regain: Althoughthere is no agreed-upon definition of a high-protein diet, studies show that consuming more than your Recommended Dietary Allowance (RDA) (0.36 grams per pound of body weight, g/lb), even double the amount (0.73 g/lb), can reduce fat and maintain lean muscle mass. High-protein diets may also help prevent weight regain.
Protein powders alone will not necessarily lead to weight loss, but they may be an effective supplement for helping you meet higher protein recommendations.
6. Caffeine
Caffeine—found in coffee, tea, and supplements—has long been explored as a tool for weight loss.
- It may not be an appetite suppressant: Some diets may suggest coffee to suppress appetite. However, studies show this is not an effective weight loss approach and may not even impact food intake or appetite.
- You may develop a tolerance to caffeine: The National Institutes of Health (NIH) states that weight loss supplements with caffeine may support short-term weight loss, but you can develop a tolerance to it, which can lessen the impact over time.
- Caffeine supplements may not be safe: The FDA has warned against taking high doses of pure caffeine in the form of supplements as it can lead to serious side effects, including erratic heartbeat, seizures, or death. The NIH states that up to 400 to 500 milligrams (mg) of caffeine is safe for most adults, and many supplements contain higher amounts.
While some small studies have shown that caffeine could support weight loss, others have shown no benefit, and supplements with caffeine can lead to nausea, vomiting, rapid heartbeat, and other, more serious side effects.
7. Green Tea Extract
Green tea and its extract, EGCG (epigallocatechin gallate), have been explored as possible weight loss aids, but the evidence doesn't suggest many benefits, as follows:
- The effects of green tea extract are small: Although some studies have shown that green tea extract may contribute to weight loss, the effect is minimal. For example, one study found that taking a high dose of EGCG in the form of green tea led to less than 1 kilogram of weight loss over 12 weeks. It’s unknown if that weight loss is maintained and for how long. The consensus is that green tea extract is not an effective tool for weight loss.
- Safety is important to consider: According to the NIH, green tea is considered generally safe at up to 8 cups per day. However, the safety limit for EGCG supplements (green tea extract) has not been established. One study suggests that healthy adults could safely consume up to 338 mg of EGCG per day. Other studies have found much higher doses have minimal benefits.
Green tea and green tea extract are not effective supplements for weight loss.
8. Bitter Orange
Bitter orange is a common ingredient in weight loss supplements. It contains synephrine, which is a stimulant that some supplement companies claim can burn calories and fat.Evidence includes:
- Bitter orange and synephrine don’t lead to weight loss: Research on bitter orange and synephrine is relatively thin, and studies are low quality. One meta-analysis of 18 studies showed that bitter orange does not lead to significant weight loss.
- Bitter orange may not be safe: It can lead to chest pain, anxiety, increased heart rate, high blood pressure (hypertension), and muscle and bone pain.
Between the safety concerns and the lack of data supporting bitter orange for weight loss, it is not recommended as a supplement for weight management.
9. B Vitamins
B vitamins play a vital role in energy production and metabolism, which has led to exploring their role in weight.Research reveals:
- B vitamin deficiency is associated with higher body mass index (BMI). However, it’s unclear if the relationship is causal in either direction—meaningB-vitamin deficiency contributing to weight gain or higher weight impacting absorption and metabolism—or if it is associated with other factors.
- Small studies in animals suggest supplements may increase metabolism. This relationship has not been shown in humans.
There isn’t any evidence to suggest that taking B vitamins helps with weight loss. However, if you have a B vitamin deficiency, supplements can help you replenish your levels, which is essential for overall health.
What Supplements Do Not Work for Weight Loss
There are dozens—if not hundreds—of supplements marketed for weight loss, most of which have no scientific backing, and many of which pose safety and health concerns. Many supplements contain a blend of ingredients that haven’t been studied together and may pose safety concerns. Common ingredients in weight loss supplements that have insufficient evidence to support weight loss include:
- Green coffee bean extract: Studies in mice have shown that when paired with a high-fat diet, green coffee bean extract may reduce weight gain. Studies in humans are limited and small and—as one analysis reports—have poor methodology. The caffeine in green coffee bean extract is a natural stimulant, which, on its own or when combined with other stimulants, can have negative health consequences. Some reports suggest that this supplement can cause headaches and urinary tract infections.
- Glucomannan: Glucomannan is a soluble dietary fiber thought to increase satiety. Several clinical studies have shown no significant impact on weight, and it may cause significant side effects, including diarrhea, constipation, and gastrointestinal distress. In higher doses, it’s also shown to cause esophageal obstruction.
- Raspberry ketones: Animal studies suggest that raspberry ketones (a natural component in raspberries) may prevent weight gain; however, there isn’t evidence to suggest this translates to humans or that they can help with weight loss. Preliminary research suggests that low doses of raspberry ketones for short periods may be safe. However, more rigorous research is needed to understand the safety.
- Garcinia cambogia: This supplement is thought to reduce the conversion of carbohydrates to fat. However, studies have shown no impact on weight. It also poses safety concerns, including increased inflammation, liver damage, and oxidative stress. Oxidative stress is the build-up of free radicals produced by normal body processes and environmental stress.
In addition to these individual supplements, proceed with caution when considering blends of ingredients, as most have not been shown to be safe or effective.
Do Weight Loss Gummies Work?
Weight loss gummies claim to burn fat, increase metabolism, and reduce your appetite. Every gummy on the market contains a different blend of ingredients, but common ingredients include apple cider vinegar (ACV), B vitamins, and now, a compounded form of semaglutide (a GLP-1 agonist).
While some small studies have shown promise for ACV diluted with water to support weight loss, others have shown no benefit. Notably, there haven’t been any studies on ACV in gummy form or when combined with other ingredients.
While injectable semaglutide has been well-studied and may support weight loss in some people, it has not been studied in gummy form or in combination with other ingredients commonly found in gummies.
The safety and efficacy of weight loss gummies are generally unknown, and no evidence supports taking them. It’s important to note that most weight loss gummies are not third-party tested, which means they could contain ingredients not listed on the label or possibly harmful contaminants. The amounts of active ingredients listed may not be accurate.
Weight Loss Management Tips Without Supplements
Rather than relying on supplements to support weight loss—which have little benefit and may not be safe—lifestyle changes can support reaching a healthy weight for you.
- Eat a balanced diet: No one diet is right for weight loss. And most diets that promote weight loss are unsustainable and result in weight regain after one to five years. Instead of restrictive diets, prioritize fiber-rich carbohydrates, fruit, lean protein, and healthy fats (nuts, avocado) for initial weight loss and maintaining a healthy weight.
- Prioritize a healthy relationship with food: Normalizing your relationship with food through intuitive eating may be helpful for weight maintenance and reducing overeating.
- Stay active: Regular movement, including a mix of cardiovascular exercises such as walking, jogging, biking, dancing, and hiking, as well as resistance training, including body weight or weight-bearing exercise, supports overall health and weight management.
- Get adequate sleep: Research suggests that people who sleep seven to eight hours per night have lower BMIs than those who get less sleep. Sleep can also impact your ability to exercise and increase hunger hormones, which may contribute to overeating.
- Manage stress: Studies show that stress and weight are interrelated, and using stress management techniques such as mindfulness, deep breathing exercises, and setting boundaries can support weight management.
- Get social support: Social support can help weight loss by providing accountability, structure, and encouragement.
When to Contact Your Healthcare Provider
Before starting any new supplement, discussing it with your healthcare provider is recommended. However, it’s essential if you:
- Take any medications: Supplements may interact with medications and make them more or less effective.
- Have underlying medical conditions: Supplements may exacerbate certain medical conditions, so ensuring a supplement is safe for you is essential.
- Take other supplements: Supplements can interact with each other, and too much of any one nutrient or ingredient may not be safe. Always review all of your supplements with your healthcare provider to determine what is safe for you.
Supplements are not risk-free, even if marketed as "natural." Always discuss any supplements you’re taking or considering taking with your healthcare provider or a registered dietitian who can evaluate your individual situation.
In the United States, the Food and Drug Administration (FDA) does not regulate dietary supplements the way it does for prescription medications. As a result, some supplement products may not contain the ingredients listed on the label. When choosing a supplement, look for products independently tested or certified by organizations such as NSF, U.S. Pharmacopeia (USP), or ConsumerLab.com. For personalized guidance, consult your healthcare provider, registered dietitian nutritionist (RD or RDN), or pharmacist.
Summary
Weight loss supplements are a big industry; many are marketed as fat-burning, metabolism-boosting, or appetite-suppressing, but there is no evidence to support these claims.
Some supplements, such as protein powders and fiber, may support weight loss when paired with other lifestyle interventions. Most others offer little to no benefit.
Certain weight loss supplements, including gummies, other combination supplements, bitter orange, and glucomannan, may be harmful to your health. So it’s important to carefully read the ingredients, look for third-party tested products, and discuss with your healthcare provider before starting a supplement.
Lifestyle changes, such as eating a balanced diet, engaging in regular exercise, getting adequate sleep, and managing stress, are the best ways to reach and maintain a healthy weight.
