Best Supplements for Fat Loss, Ranked by Clinical Evidence

70 supplements · 4 outcomes · 102 trials

Our #1 pick

Green Tea Extract (EGCG) Proven benefit Strong · 92

The best-proven fat-loss boost when you're already exercising

400 to 500 mg of EGCG daily, equivalent to about 4 to 5 cups of brewed green tea. Most positive trials used catechin-rich extracts in the 500 to 1000 mg total catechin range.

8 to 12 weeks before measurable changes in body fat. Some metabolic effects like increased fat oxidation show up within days, but body composition changes require consistency.

Let's get something out of the way: no supplement will replace a calorie deficit. If you're eating more than you burn, creatine and green tea aren't going to save you. The entire supplement industry wants you to believe otherwise, because "take this pill and lose weight" is a much easier sell than "eat less and move more."

But within the context of a reasonable diet and exercise program, a small number of supplements have been shown to nudge body composition in the right direction. The effects are modest. We're talking about losing an extra pound or two of fat over 8 to 12 weeks, or shifting your body fat percentage down by a point. That's real, but it's not transformative.

This list ranks supplements by the strength and consistency of clinical evidence for reducing body fat specifically, not just body weight (which can drop from water loss or muscle loss). We prioritized trials that measured body composition with medical-grade tools like body scans and impedance analysis, not just bathroom scales. And we filtered out supplements where the evidence comes from irrelevant populations or implausibly large effect sizes from single studies.

The honest takeaway: a few of these supplements are worth adding to an already-solid training and nutrition program. None of them are worth anything without one.

#1 deep dive

Why Green Tea Extract (EGCG) takes the top spot

How it works

EGCG inhibits catechol-O-methyltransferase, an enzyme that breaks down norepinephrine. With norepinephrine circulating longer, fat cells get a stronger signal to release stored fat for burning.²⁰ Catechins also appear to increase the proportion of calories burned from fat during exercise, effectively turning up the ratio of fat-to-carbohydrate your body uses as fuel.⁴

What the research says

A 2024 meta-analysis of randomized trials in overweight and obese adults found that adding green tea catechins to an exercise program produced a consistent additional reduction in both body weight and fat mass beyond what exercise alone achieved.²⁰ An earlier trial in 65 adults showed measurable fat loss at 12 weeks.¹⁹ Green tea also has proven effects on fasting blood sugar, liver enzymes, and cholesterol, making it one of the more broadly useful metabolic supplements.⁴ The fat-loss effect is small but real, roughly equivalent to losing an extra kilogram of fat over three months of combined supplementation and training.

Best for

People who are already exercising regularly and want to squeeze a bit more fat loss out of their program. The evidence is strongest in overweight adults combining green tea with structured training.

Watch out

Green tea extract can interact with blood pressure medications (nadolol, lisinopril) and blood thinners (warfarin). High-dose EGCG extracts have been linked to rare liver irritation. Take with food and avoid fasted mega-doses.

Pro tip

Take green tea extract before your workout to maximize fat oxidation during exercise. If you're caffeine-sensitive, look for decaffeinated EGCG extracts, which retain the catechin content without the stimulant effect.

Evidence by outcome

Reduce total body fat Proven benefit

Helps lower the total kilograms of fat your body carries.

d=0.29 Small effect 2 endpoints trust 92

Creatine Monohydrate

Proven benefit

Strong · 93 Minimal effect

Builds muscle that shifts your body fat percentage down

3 to 5 g daily. No loading phase needed for body composition goals. Consistency over months matters more than dose timing.

8 to 12 weeks to see measurable body composition shifts. Creatine works by helping you train harder and build more muscle, which is not an overnight process.

Full breakdown

How it works

Creatine replenishes the phosphocreatine system that powers short, intense efforts like lifting heavy weights or sprinting.⁶ By letting you do more work in each training session, creatine accelerates muscle growth. More muscle mass means a higher resting metabolic rate and a lower body fat percentage even if total fat mass stays roughly the same.⁹¹⁰

What the research says

A 2024 meta-analysis of 15 studies in healthy adults under 50 found that creatine plus resistance training reduced body fat percentage by nearly a full percentage point and cut about 0.7 kg of fat mass compared to training alone.¹⁰ A separate 2014 meta-analysis in older adults found similar lean mass gains but no significant fat loss, suggesting the fat-loss benefit is strongest in younger, actively training populations.⁶ Across 9 studies tracking body fat percentage, the effect is consistent but small, with most of the body composition improvement coming from muscle gain rather than direct fat burning.⁹¹¹

Best for

People doing serious resistance training who want to maximize muscle gain and recomposition. Creatine doesn't burn fat directly. It helps you build the muscle that changes your body composition over time.

Watch out

Creatine causes 1 to 2 kg of water retention in the first week, which shows up on the scale. This is not fat gain. If you're tracking progress by weight alone, this initial bump can be misleading.

Pro tip

Ignore loading protocols and fancy creatine forms. Plain creatine monohydrate at 3 to 5 grams per day is the most studied, cheapest, and most effective form. Take it at any time of day with water.

Evidence by outcome

Lower body fat percentage Proven benefit

d=0.36 Minimal effect 9 endpoints trust 93

Reduce total body fat Likely helps

d=0.20 Minimal effect 8 endpoints trust 74

Improve body composition Likely no effect

d=0.00 Minimal effect 1 endpoints trust 67

Reduce fat under the skin Not enough research

d=0.17 Minimal effect 1 endpoints trust 37

Collagen Peptides

Proven benefit

Strong · 79 Moderate effect

A surprising body-recomp signal from skin and joint trials

15 g daily of hydrolyzed collagen peptides. This is the dose used in virtually every positive body composition trial.

12 weeks. Every trial showing fat loss ran for at least three months of daily supplementation combined with resistance training.

Full breakdown

How it works

The mechanism here is not fully understood, and that's worth being honest about. The leading hypothesis is that collagen peptides provide amino acid building blocks (particularly glycine, proline, and hydroxyproline) that support connective tissue growth during resistance training.²⁵ This may contribute to increases in fat-free mass that include tendons, ligaments, and fascia, not just contractile muscle tissue.²⁸ Some researchers also speculate that collagen's high satiety effect may reduce overall calorie intake.²³

What the research says

This is one of the more surprising entries on the list. Across 9 human trials involving over 550 participants, collagen peptide supplementation combined with resistance training consistently produced greater fat loss than training with placebo.²⁵²⁶²⁷²⁸²⁹³⁰ A 2015 trial in 60 older men with sarcopenia found the collagen group lost roughly 5.4 kg of fat while gaining 4.2 kg of lean mass over 12 weeks.²⁵ A 2019 trial in 57 young trained men showed collagen prevented the fat gain seen in the placebo group during a training program.²⁸ A 2021 trial in 120 overweight middle-aged men confirmed the pattern with significant reductions in fat mass alongside lean mass gains.³⁰ The effect on fat mass measured by body scans is consistent, but the mechanism is still debated.

Best for

People doing resistance training who want an extra body composition edge, especially adults over 40. The evidence is strongest when collagen is paired with structured exercise. If you're already taking collagen for joint or skin benefits, the body composition effect is a useful bonus.

Pro tip

Take collagen peptides within an hour of training. Several trials specifically timed the supplement pre- or post-workout. Collagen is not a complete protein for muscle building (it's missing tryptophan), so don't use it as your primary protein source.

Evidence by outcome

Reduce total body fat Proven benefit

d=0.06 Moderate effect 11 endpoints trust 79

Lower body fat percentage Not enough research

2 endpoints trust 16

Improve body composition Not enough research

d=0.36 Small effect 1 endpoints trust 11

Resveratrol

Proven benefit

Strong · 95 Minimal effect

Tiny fat-loss effect, but strong metabolic benefits underneath

150 to 500 mg daily. The umbrella review found that doses above 400 mg per day and treatment durations beyond 12 weeks produced stronger results.⁴

12 to 24 weeks. The body fat effects take longer to materialize than the metabolic improvements in insulin and blood sugar, which can appear within 8 weeks.

Full breakdown

How it works

Resveratrol activates SIRT1, a protein that regulates cellular energy metabolism and fat storage. When SIRT1 is more active, cells shift toward burning fat for fuel rather than storing it, and insulin sensitivity improves.¹ A trial in type 2 diabetics confirmed that people whose SIRT1 levels rose the most also lost the most body fat.¹ Resveratrol also improves insulin resistance and reduces inflammation, both of which contribute to metabolic fat accumulation over time.³

What the research says

A 2025 umbrella review pooling data from multiple meta-analyses found that resveratrol produces small but statistically significant reductions in body weight, waist circumference, and fat mass, with stronger effects at higher doses and longer durations.⁴ A 2022 meta-analysis tracking glucose and lipid metabolism across over 1,000 participants found a trend toward lower body fat percentage, though it didn't reach statistical significance on its own.² The fat-loss effect is real but trivial in isolation. Where resveratrol earns its place is the broader metabolic picture: proven reductions in fasting insulin, insulin resistance, HbA1c, and triglycerides across large, high-trust evidence bases.⁵³ For someone dealing with metabolic syndrome or insulin resistance, the fat-loss effect is a small bonus on top of meaningful metabolic improvements.

Best for

People with insulin resistance, metabolic syndrome, or prediabetes who want body composition benefits alongside metabolic improvement. Not a primary fat-loss supplement for lean, healthy individuals.

Watch out

Resveratrol inhibits CYP3A4 and CYP2D6 enzymes, which means it can alter the metabolism of many common medications including blood thinners, certain antidepressants, and blood pressure drugs. Check with your pharmacist if you take prescription medications.

Pro tip

Look for trans-resveratrol specifically. Take with a meal containing some fat for better absorption. Pair with exercise for the largest metabolic benefit.

Evidence by outcome

Reduce total body fat Proven benefit

d=0.20 Minimal effect 3 endpoints trust 95

Lower body fat percentage Likely helps

d=0.26 Small effect 2 endpoints trust 74

Betaine (Trimethylglycine)

Likely helps

Strong · 68 Moderate effect

A gym-science sleeper with growing body composition data

2.5 g daily. This is the dose used in virtually every body composition trial. Some performance studies have used up to 6 g.

6 to 10 weeks. The earliest body composition changes showed up at 6 weeks in strength-trained men.

Full breakdown

How it works

Betaine is a methyl donor that supports creatine synthesis and helps regulate cellular hydration. In muscle cells, betaine acts as an osmolyte, maintaining cell volume under stress, which may promote anabolic signaling during resistance training.¹⁴ Betaine also lowers homocysteine, a marker of cardiovascular stress, through the BHMT enzyme pathway.¹⁷

What the research says

A 2019 meta-analysis of six RCTs totaling 195 participants found that betaine supplementation significantly reduced both total fat mass and body fat percentage, though body weight and BMI did not change.¹⁵ This pattern, less fat without less weight, suggests betaine shifts body composition toward more muscle and less fat rather than causing net weight loss. A 2013 trial in experienced lifters found reduced body fat, increased lean mass, and improved arm size after 6 weeks at 2.5 g daily.¹⁴ A 2023 trial in CrossFit athletes confirmed increased testosterone and fat-free mass with betaine supplementation.¹⁸ The evidence is promising but still thin. Most trials are small (under 50 participants) and conducted in young, trained men.

Best for

Resistance-trained individuals looking for a body recomposition edge. The evidence is specifically in people who are already lifting. If you're sedentary, betaine is unlikely to change your body composition.

Pro tip

Betaine is cheap and widely available as trimethylglycine powder. It tastes mildly sweet. Mix it into your pre-workout shake or take it with food.

Evidence by outcome

Reduce total body fat Likely helps

d=0.25 Moderate effect 5 endpoints trust 68

Lower body fat percentage Early data

d=0.27 Small effect 4 endpoints trust 42

Reduce fat under the skin Early data

d=0.27 Small effect 1 endpoints trust 35

Inulin (Chicory Root Fiber)

Likely helps

Strong · 69 Minimal effect

Feeds the gut bacteria that influence your metabolism

10 to 16 g daily. Start at 5 g and increase gradually over two weeks to avoid GI discomfort. The effective range in trials was 8 to 30 g.

8 to 12 weeks for body composition changes. Gut microbiome shifts begin within 1 to 2 weeks, but metabolic downstream effects take time to accumulate.

Full breakdown

How it works

Inulin is a prebiotic fiber that passes through the small intestine undigested and feeds Bifidobacterium and other fiber-fermenting bacteria in the colon. These bacteria produce short-chain fatty acids, particularly butyrate and propionate, which signal through gut hormones (GLP-1, PYY) to improve insulin sensitivity and appetite regulation.⁷⁸ The result is a slower, indirect influence on body fat through metabolic and appetite pathways rather than direct fat burning.

What the research says

Across five trials tracking total body fat mass, inulin supplementation shows a likely beneficial effect, though the magnitude is small.⁷⁸ The stronger evidence is for inulin's metabolic effects: proven reductions in fasting blood sugar, BMI, and body weight across larger evidence bases with high confidence.⁷ Inulin also has proven benefits for gut microbiome diversity and stool quality, making it a multi-benefit supplement where fat loss is one piece of a broader metabolic picture. The body fat percentage finding is less convincing, with one analysis suggesting no clear effect on that specific measure.

Best for

People with metabolic concerns (blood sugar regulation, insulin resistance) who would benefit from improved gut health alongside modest fat-loss support. Particularly useful for anyone eating a low-fiber diet.

Watch out

Bloating and gas are common at higher doses, especially in the first two weeks. Start low (5 g) and ramp up. People with IBS or FODMAP sensitivity may not tolerate inulin well.

Pro tip

Inulin dissolves easily in hot or cold liquids and has a mildly sweet taste. Add it to your morning coffee or oatmeal. Pair it with a diet that already includes some fiber rather than going from zero to 15 g overnight.

Evidence by outcome

Lower body fat percentage Likely no effect

d=0.00 Minimal effect 4 endpoints trust 70

Reduce total body fat Likely helps

d=0.15 Minimal effect 5 endpoints trust 69

Hydroxycitric Acid (Garcinia Cambogia)

Proven benefit

Strong · 92

The most-hyped fat burner with the weakest evidence

1500 to 3000 mg daily of HCA, typically divided into three doses before meals.

2 to 12 weeks in trials. The meta-analysis pooled results across this wide range.

Full breakdown

How it works

HCA inhibits ATP citrate lyase, an enzyme that converts excess carbohydrates into fat.¹⁷ In theory, this blocks a step in the fat synthesis pathway and may increase serotonin to reduce appetite. The biochemistry is plausible on paper.

What the research says

A 2011 meta-analysis of randomized trials in overweight adults found a small weight loss with HCA versus placebo, but the effect shrank in sensitivity analyses that only included higher-quality trials.¹⁷ A 2023 RCT in 44 obese women with fatty liver found that HCA reduced visceral fat when added to a calorie-restricted diet, but this was a small, single-center trial in a specific clinical population.¹⁸ The meta-analysis concluded that the effect is of uncertain clinical relevance and called for better-designed studies. Notably, there is an early signal that HCA may actually increase cravings for fatty foods.¹⁸ Despite being one of the most heavily marketed fat-loss supplements worldwide, the clinical evidence is surprisingly thin.

Best for

Honestly, almost nobody based on current evidence. If you have NAFLD and are already on a calorie-restricted diet, the visceral fat finding is mildly interesting, but this is not a general-purpose fat burner.

Watch out

GI side effects are common. There are case reports of liver toxicity, though causality is debated. A 2012 safety review flagged potential hepatotoxicity concerns at high doses.

Evidence by outcome

Reduce total body fat Proven benefit

2 endpoints trust 92

What doesn't work

Save your money on these

Garcinia Cambogia Not enough research

Despite being one of the best-selling weight loss supplements worldwide, garcinia cambogia has almost no credible fat-loss evidence. We found one small trial and a 2011 meta-analysis that called its own findings 'of uncertain clinical relevance.' The effect disappears in higher-quality studies.

CLA (Conjugated Linoleic Acid) Not enough research

CLA was heavily marketed in the 2000s based on animal studies showing dramatic fat loss in mice. Human trials have been consistently disappointing, and meaningful clinical evidence for fat loss in humans barely exists. The marketing ran far ahead of the science.

L-Carnitine Not enough research

L-carnitine is marketed as a 'fat shuttle' that moves fatty acids into mitochondria for burning. The biochemistry is real, but your body already makes plenty of carnitine. Supplementing more doesn't increase fat burning in healthy people. Clinical trials have not shown meaningful body fat reduction in people who aren't carnitine-deficient.

Capsaicin / Cayenne Pepper Not enough research

Capsaicin does temporarily increase metabolic rate, but the effect is tiny and fleeting. Multiple trials found no meaningful body weight change, and the one body fat signal was from a single small study. The thermogenic boost sounds exciting but translates to maybe 10 extra calories burned per day.

Synergistic stacks

Combinations that work better together

The Training Stack

Green Tea Extract + Creatine Monohydrate

Green tea increases fat oxidation during exercise while creatine helps you train harder and build more muscle. Different mechanisms, no interaction concerns.

Green tea extract 30 minutes before training. Creatine 3-5g at any time daily.

The Recomp Stack

Creatine Monohydrate + Collagen Peptides

Creatine drives muscle growth while collagen supports connective tissue and shows independent fat-loss effects. Both work best with resistance training.⁶²⁵

Creatine 5g daily. Collagen 15g within an hour of training.

The Metabolic Stack

Green Tea Extract + Inulin

Green tea works through catecholamine-driven fat oxidation while inulin works through gut bacteria and metabolic signaling. Complementary pathways with no overlap.

Green tea extract with breakfast. Inulin 10-15g in the evening, ramped up gradually.

Buying guide

What to look for on the label

Form matters

•Green tea extract should list EGCG or total catechin content, not just milligrams of green tea powder. You want 400 to 500 mg of actual EGCG.
•Creatine monohydrate is the only form with strong evidence. Skip creatine HCl, buffered creatine, or creatine ethyl ester, which are more expensive with no proven advantage.
•Collagen peptides should be hydrolyzed for absorption. 'Type I and III collagen' on the label is standard. Look for products that specify the peptide weight (typically 2.5 to 15 g per serving).
•Betaine is sold as trimethylglycine (TMG) in bulk powder or capsules. Betaine HCl is a different product used for digestion, not body composition.

Red flags

•Any product claiming to 'melt fat' or produce rapid weight loss without diet or exercise. The supplements on this list produce modest effects alongside training.
•Proprietary blends that hide individual ingredient doses. You need to know exactly how much EGCG, creatine, or collagen you're getting.
•Fat burner stacks combining stimulants (caffeine, synephrine, yohimbine) with thermogenics. These raise heart rate and anxiety more reliably than they reduce body fat.

Quality markers

•Third-party testing (NSF Certified for Sport, Informed Sport, USP Verified) ensures the product actually contains what the label says and is free of contaminants.
•Clinical doses that match the research. If a trial used 500 mg of EGCG and the product contains 50 mg, it's underdosed regardless of quality.

The bottom line

The supplements on this list produce real but modest reductions in body fat when combined with exercise and reasonable nutrition. Green tea extract paired with training has the cleanest evidence for a direct fat-loss boost. Creatine shifts body composition by adding muscle, which indirectly reduces body fat percentage. Collagen peptides show a surprisingly consistent fat-loss signal across multiple resistance training trials, though the mechanism is still being sorted out.

Resveratrol and betaine round out the list with legitimate but smaller signals, both better suited for people with metabolic concerns than for lean athletes chasing the last percentage point. Inulin works through a completely different pathway, feeding gut bacteria that influence metabolic signaling.

If you're looking for a single practical recommendation: green tea extract plus a resistance training program is the most straightforward, well-supported approach. Add creatine if you're training seriously. Everything else on this list is fine-tuning.

And if someone tries to sell you garcinia cambogia, raspberry ketones, or CLA for fat loss, save your money.

Frequently asked

Common questions

Do fat-burning supplements actually work?

A few supplements have clinical evidence for modest fat reduction, but only when combined with exercise and reasonable nutrition. Green tea extract, creatine, and collagen peptides all show real effects in randomized trials, but we're talking about losing an extra pound or two of fat over 2 to 3 months, not dramatic transformations.²⁰¹⁰

What's the best supplement for losing belly fat specifically?

Most fat-loss supplements reduce total body fat rather than targeting belly fat specifically. That said, green tea extract has separate evidence for reducing waist circumference, and resveratrol shows waist reduction in people with metabolic conditions.⁴ Spot reduction from supplements isn't really a thing.

Is creatine good for fat loss even though it causes weight gain?

Creatine causes 1 to 2 kg of water weight gain in the first week, which is not fat. Over 8 to 12 weeks of resistance training, creatine helps you build more muscle and lose more fat than training alone, improving your body fat percentage even if the scale doesn't drop as much as you'd expect.¹⁰

Are thermogenic fat burners worth it?

Most thermogenic supplements (caffeine, capsaicin, green tea) increase metabolic rate by a small amount. But the calorie burn from thermogenesis alone is minimal, maybe 50 to 100 extra calories per day at best. Green tea extract is the only thermogenic with consistent fat-loss evidence from clinical trials, and even that requires exercise to show meaningful results.²⁰

How long do I need to take fat-loss supplements to see results?

Minimum 8 weeks, and most trials ran for 12 weeks. Body composition changes are slow. If someone promises visible fat loss in a week from a supplement, they're either selling a diuretic or lying.

Want personalized body fat reduction recommendations?

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Sources

Generated April 4, 2026