The 10 Best Supplements for Weight Loss

1. Whey protein

It’s no secret that protein is a gym junkie’s best friend. But it actually does more than just carve cut muscles—a 2014 meta-analysis in the Journal of the American College of Nutrition found that people lost roughly 10 pounds after incorporating whey protein into their diet. And the milk derivative actually outperforms other protein sources: Overweight individuals who drank one whey protein shake a day lost more weight than those who drank a soy protein shake, according to a study in theJournal of Nutrition.

It works in a few ways: Whey suppresses your appetite, therefore helping you eat less, but it’s also one of the best aids in building muscle, says Franci Cohen, certified nutritionist, exercise physiologist, and founder of Fuel Fitness in Brooklyn. “Muscle has a higher metabolic rate than fat, so every pound of fat you replace with muscle in turn increases your metabolism and fat-burning abilities a bit more,” she explains. Plus, because it contains the same molecules as carbs and fats, plus one more (nitrogen), protein requires more energy to digest, so you’ll burn more calories as your body processes the nutrient, Cohen adds.

2. Caffeine (methylxanthine)

A little jolt has been linked to a whole slew of health benefits, from improving alertness to lowering risk for cancer, but it’s also one of the best—if not the best—researched ergogenic aids available today, says Rehan Jalali, certified sports nutritionist and president of the Supplement Research Foundation. Several studies have shown caffeine helps promote fat oxidation—or your body’s ability to break down large fat molecules to use as energy—as well as both weight and fat loss in active people, he adds. Whereas most of the health benefits come from its antioxidants, caffeine helps you lose fat by stimulating your central nervous system. This encourages the release of several molecules and nutrients in your body, including stored fat to be burned for energy and calcium to help muscle contraction. Plus it can help you work out harder: In a study in the Journal of Applied Physiologylast year, guys who ingested caffeine before a workout burned more calories during, ate less calories after, and actually enjoyed their gym time more than when they hit the weights without the kick. But cap your daily intake at 400 mg—too much of a jolt can increase anxiety, your risk of cardiovascular disease, and insulin sensitivity which can actually cause you to gain weight.

3. Green tea extract

“Green tea extract may increase fat oxidation and even stimulate brown adipose tissue thermogenesis—special fat cells that can actually help speed up your metabolism, which is good news for anyone looking to lose body fat,” says Jalali. The key is in the plant’s phytochemicals, particularly epigallocatechin gallate (ECGC), which a study in the European Journal of Clinical Nutrition found, at low doses, can increase your fat oxidation by 33 percent. Jalali advises looking for a supplement with 50% EGCG and 90% polyphenols for the best burn.

4. Glutamine

The most abundant amino acid naturally produced by your body, glutamine is found in the largest amounts in your muscles, helping repair them, maintain a healthy gut, and stabilize your blood sugar. A study last year in the European Journal of Clinical Nutrition found that without changing their diets at all, people lost weight after taking glutamine supplements for four weeks, likely because it helped boost glucose metabolism.

5. Chitosan

This fiber, commonly called “shark cartilage,” comes from the exoskeletons of insects and crustaceans. Research is mixed, but a large study analysis in the Journal of Obesity found that when people took chitosan twice a day with food, they had significantly lower BMIs and body fat as well as less bloating and flatulence than people who took a placebo. It doesn’t have magical fat burning abilities, but, because it’s a type of dietary fiber, it may help keep you full longer, which in turn leads to you eating less, Cohen explains.

NOTE: Take this supp at a different time than you do the others (so if you take the others in the AM, take this one in the afternoon or vice versa.) “Chitosan may bind the other nutrients and lower absorption rate,” explains Jalali.

6. Hydroxycitric acid (HCA)

Derived from a salt taken from the rind of a Southeast Asian dried fruit plant, HCA helps suppress your appetite, reduce the amount of fat your body absorbs from your diet, and increase your metabolism, explains Cohen. When compared to taking a placebo, HCA supplements can help decrease the amount of visceral, subcutaneous, and total fat, according to a 2011 British study. HCA is often sold in the form of garcinia extract—the name of the plant it’s derived from. But this is useless if it doesn’t have the right amount of the active ingredient, Cohen adds. Look for either a pure HCA supplement or a garcinia extract with 50 percent HCA.

7. Cayenne pepper

The research in support of cayenne pepper for weight loss is on fire: Taking half a teaspoon in a capsule can help you eat fewer calories later in the day and crave sweet and salty snacks less, according to a study from Purdue University. Meanwhile, UCLA researchers have found that eating meals with capsaicin—the root of pepper’s heat—helps increase your metabolism by 15 to 20% for up to two hours after. Plus, research presented at the Biophysical Society Annual Meeting earlier this year found that capsinoids can help activate white and brown fat cells, helping to better regulate your metabolism. The secret is in the fact that capsaicin activates your sympathetic nervous system, which is what controls your adrenaline and fight or flight response, explains Jalali (also why you feel warmer when you eat the heat).

8. Vitamin D

The sunshine vitamin does more than just ward off depression—Italian research earlier this year found that a vitamin D deficiency is associated with a higher risk of obesity. And, since some 40% of American adults are deficient in the stuff, according to the Centers for Disease Control and Prevention, it may benefit your midsection to supplement, particularly during winter. Vitamin D is necessary for the proper function of receptors all over your body, including ones that tell your systems whether to store or burn fat, whether you’re hungry, and what you’re craving. In fact, a 2009 study from the University of Minnesota found that those who start a diet with healthy levels of vitamin D actually lose more weight than those who try and change their eating habits with an empty D bank.

9. Olive leaf extract

Just like antioxidant superstar olive oil, extract from the plants leaves is chock full of polyphenols and flavonoids that help lower inflammation and stabilize blood sugar, Jalali explains. Besides protecting the body from harmful free radicals, studies have shown that olive leaf extract supports fat loss by improving how efficiently insulin works in your body, thereby reducing the amount of fat your body stores. Research in the American Journal of Nutrition found the supplements helped rats lose weight, while another study out of Isreal found that the extract can help normalize glucose levels, causing less cravings and better blood sugar balance.

10. Chromium

This trace mineral is essential for our body to be able to metabolize macronutrients properly. “Chromium helps insulin metabolize fat, turn protein into muscle, and convert sugar into energy, plus it plays a key role in regulating appetite, reducing sugar cravings, and increasing lean body mass,” says Jalali. Not only is the element necessary for weight control, but you lose most of your stores during vigorous exercise, so it’s extra important for active guys to replenish, Jalali adds.