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The #1 Best Supplement for Weight Loss, Say Dietitians

Here's how to determine the best supplement that works for you.
FACT CHECKED BY Olivia Tarantino

With more than 50,000 dietary supplements on the market, you can just imagine how many of those are marketed as weight-loss products. It's a multi-billion-dollar industry. So, trying to find agreement on what the #1 best dietary supplement for weight loss is a toss-up.

Most weight-loss supplements contain such common ingredients as vitamins, minerals, caffeine, fiber, protein, herbs, and other plant compounds purported to burn fat, boost energy, build muscle, lower blood sugar or simply improve nutrition. Many nutritionists and other weight-loss experts have their favorite ingredients, while others think whole foods are the way to go. So, choosing the one pill, powder, gummy, or drink that may work best for you will require some trial and error. The #1 dietary supplement that works for others may not work for you, which is why it's important to peruse your options—and talk to your doctor—to make a decision that makes sense for your body.

Do weight loss supplements work?

Many nutritionists and weight-loss coaches sell their own formulations of their favorite ingredients or certain manufacturers' products; that alone should make you wary when considering weight-loss supplements recommended by them.

Recent studies have called the efficacy of weight-loss supplements into question, including a large review of 121 placebo-controlled trials of herbal and dietary supplements involving nearly 10,000 adults over 16 years presented recently at The European Congress on Obesity.

"Our rigorous assessment of the best available evidence finds that there is insufficient evidence to recommend these supplements for weight loss," said Erica Bessell, a practicing dietitian, PhD candidate from the University of Sydney in Australia, and lead investigator of the studies, in a statement. "Even though most supplements appear safe for short-term consumption, they are not going to provide weight loss that is clinically meaningful," she said.

A similar study published in the International Journal of Obesity Supplements in 2019 focused on efficacy and possible drug interactions of common ingredients used in dietary supplements. That research determined that the effectiveness of weight-loss dietary supplements "is still inconclusive and the cost of these products can be considerable." Study researchers concluded that "healthy diet and physical activity remain the first-line intervention for weight loss."

Here's what some dietitians and other nutrition coaches we surveyed recommend as the best supplements for weight loss. Then, be sure to read up on our list of 15 Underrated Weight Loss Tips That Actually Work.

Fiber supplements

young woman taking supplement
Shutterstock / fizkes

The best way to ensure weight loss is getting enough dietary fiber from fruits and vegetables, says Morgyn Clair, RD, a nutritionist for Sprint Kitchen. Problem is, most people don't eat enough fiber-rich plants to get the recommended minimum of 25 to 30 grams of fiber a day, so she recommends supplementing.

"People can easily get this through an over-the-counter supplement like Benefiber," she says.

That product is made from a soluble fiber called Inulin (chicory root fiber). Another popular soluble fiber supplement, Metamucil, uses psyllium fiber. If you don't want to take a fiber supplement, you can boost your fiber intake by adding flax meal to your soups, salads, and smoothies. "It's an excellent source of fiber for those who have low fiber intake and it's tasteless," says Fiorella Di Carlo, RD, CDN, cooking video host of Living in Italian.

Related: Best Supplements for a Longer Life.

Polyphenol multivitamins

multivitamin supplement

While most supplements produce mild results at best, a good multivitamin containing polyphenols that fight free radicals and support a healthy metabolism may help your weight loss efforts, says Lisa Moskovitz, RD, CDN, CEO of NY Nutrition Group, and one of our medical expert board members. She recommends a particular polyphenol multivitamin called Oh Grape by Groove.

"With 500 milligrams of resveratrol, this supplement offers antioxidant properties that fight against free radical damage, supports healthy hormone balance—especially insulin—and decreases inflammation in the body," Moskovitz says.

This supplement also contains 2,000 IU of vitamin D, which studies show can be directly linked to weight and metabolism and magnesium that may support blood sugar stabilization, appetite, and energy.

"Oh Grape also packs in vitamin C, which is not only supportive of the immune system but helps fight against inflammation in the body that along with other factors, can contribute to weight gain over time," she says.

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Green tea extract or EGCG supplements

green tea extract

EGCG (epigallocatechin gallate) is a powerful catechin (natural flavonoid) found in green tea.

"EGCG supplements can help you burn more calories—even at rest, and studies show the compound can result in weight loss," says nutrition counselor Lauren Manaker, MS, RDN with Zhou Nutrition.

She points to a study in the Journal of Nutrition that links drinking green tea with enhancing exercise to accelerate belly fat loss in obese adults.

Check out the #1 Best Green Tea to Drink, According to Experts.



Berberine is a chemical compound found in some plants that has been shown to help regulate blood sugar and blood fats so it is commonly taken for type 2 diabetes and high cholesterol.

"It works in a variety of ways to help with weight loss—minimizing absorption of carbs and sugars with food, helping reduce insulin spikes and activating AMP-activated protein kinase to support metabolism, which is why I use it in our Carb & Sugar Blocker supplement," says Stephanie Redmond, PharmD, CDCES, co-founder of

Some people who take berberine complain of stomach upset or constipation, but it's generally well tolerated, says Dr. Redmond, who notes that it can be used in combination with common type 2 diabetes medications such as metformin for added benefits since it works by a different mechanism.

B-complex, magnesium, and iron

B-complex pills on a clay plate

"The best vitamins for increasing metabolism are those that work to help your body create energy from the food and nutrients you take in," says nutritionist Lisa Richards.

She recommends a B-complex supplement (which contains 8 B vitamins) to help your body metabolize stored carbohydrates and fat for fuel, aiding in weight loss and increasing metabolism.

"Magnesium and iron are two minerals used by the body to create energy from food," she says. "Taking these two supplements in the morning will help your body to use nutrients for energy rather than storing them as fat."

Prebiotic and probiotic supplements

probiotic supplement

If you want to lose weight, "my tip is to get your gut health in order because it is at the core of all bodily functions involved with the process of weight loss; probiotics can help with this," says rheumatologist Anthony S. Padula, MD, at the Northern California Arthritis Center in Walnut Creek, CA. and a "Gut Council" member for Jetson Probiotics. "Your gut bacteria (your microbiome) can affect how you digest food, store fat and chemicals that make you feel full or hungry. Probiotic foods contain live strains of bacteria that increase the population of good bacteria in your digestive system, while prebiotic foods contain types of fiber that act as food for good bacteria. Both sources are designed to increase the number of bacteria in your gut and improve your microbiome."

The gut bacteria play many roles in both weight loss and weight gain, adds Trista Best, RD, MPH, a registered dietitian at Balance Once Supplements. "When gut bacteria is off the short-chain fatty acid production in the gut is amped up which triggers appetite hormone production." Probiotics in supplement form are living bacteria that provide countless health benefits when ingested, including improving appetite regulation, she says.


Turmeric pill supplement

Inflammatory foods like fried and highly processed foods can trigger inflammation in the body, which can impair the ability of the hormone insulin to work properly. That often leads to insulin resistance, which in turn may cause higher blood sugar and fat accumulation in the liver. Curcumin, the active ingredient in turmeric, has been shown to reduce inflammation.

"Turmeric can be an excellent addition to an existing weight-loss regimen due to its anti-inflammatory capabilities," says Best. It can be taken in either capsule or powder form.

Collagen peptides


Collagen peptides are very small pieces of protein from animal collagen. Studies have shown that this protein supplement can help us feel fuller longer, leading to fewer overall calories consumed throughout the day, says Mackenzie Burgess, RDN, a nutritionist and recipe developer at Cheerful Choices. "As a dietitian, one of my favorites to use is Naked Nutrition Collagen Peptides Protein Powder. I love how it contains only one ingredient–bovine hide collagen peptides–and provides 9 grams of protein per scoop." She recommends adding it to coffee, a smoothie or overnight oats to pump up the protein and satiety effect.


supplements and vitamins

Anxiety has been linked to weight gain because the stress hormone cortisol, which is released when you are tense, increases insulin levels, causing a blood sugar drop that triggers cravings for carbs and junk food. The problem with many weight loss supplements is that they are "fat burners and energy supplements, all of which cause a certain level of stress on our bodies and activate cortisol," says Jacyln Bauer, PhD, a clinical psychologist and founder of Virtue Supplements. Because she believes "the real reason someone can't lose weight is stress," Dr. Bauer developed a stress-relieving supplement that combines pharma-GABA, with lavender oil, lemon balm, flaxseed, and theanine, an amino acid with anti-stress effects that is found in green and black tea.

Vitamin K

Yellow pills forming shape to K alphabet on wood background

As we suggested earlier, the effectiveness of most weight-loss supplements has not been definitively proven. But that doesn't stop millions of people from buying them to hopefully boost their chances of slimming down. There is, however, one indisputable key to sustainable weight control: learning to eat right.

According to Medical News Today, supplements that help to suppress your appetite still don't teach you how to eat, so it's important to learn the proper healthy eating habits for weight loss instead of simply relying on supplements to do it for you.

This may help: Ways Intuitive Eating Can Help You Lose Weight, Say Dietitians.

Jeff Csatari
Jeff Csatari, a contributing writer for Eat This, Not That!, is responsible for editing Galvanized Media books and magazines and for advising journalism students through the Zinczenko New Media Center at Moravian University in Bethlehem, PA. Read more about Jeff