Ranked by evidence
Best supplements for weight loss
No capsule produces meaningful weight loss on its own; any real loss comes from an energy deficit, and the best-supported product simply makes that deficit easier to keep. Everything below is ranked by the grade of the evidence for body weight, and most effects are around a kilogram or two. The stimulant and botanical fat burners are in the skip list for good reason.
Picks are ranked by the strength of published evidence for this goal in otherwise healthy adults. A persistent symptom needs a clinician's evaluation, and no supplement on this list replaces treatment.
Evidence last reviewed: September 2026
Top picks
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Meal Replacement Shakes | Strong evidence | structured calorie control | Meal-replacement diets beat conventional calorie restriction in trials, by roughly 1–3 kg over 3–12 months, with one or two 200–400 kcal shakes a day. The benefit comes from structure and adherence, and weight tends to return when the structure stops. | View |
Solid options
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| L-Carnitine | Moderate evidence | a small extra loss | A meta-analysis of 37 trials found about 1.2 kg more weight loss than placebo, with no added benefit above about 2 g/day. The effect shrank as trials ran longer. | View |
| Carb Blocker Formulas | Moderate evidence | starch-heavy meals | White kidney bean extract reduced weight by 1.62 kg versus placebo in a meta-analysis of eight small trials, most linked to ingredient makers. It only works taken before meals that contain starch, and gas and bloating are common. | View |
| Cayenne (Capsaicin) | Moderate evidence | slightly lower food intake | Capsaicinoids reduce intake by roughly 70–75 kcal per meal and slightly raise energy expenditure. No long trial shows meaningful weight loss, and the thermogenic effect fades with habitual chilli use. | View |
| Oat Beta-Glucan | Strong evidence | feeling full on fewer calories | Beta-glucan increases fullness and reduces later energy intake, but weight-loss trials show only small effects, typically under 1–2 kg. Treat it as a useful dietary component rather than a weight-loss agent. | View |
Situational
Popular for this goal — but the evidence says skip
- Garcinia Cambogia Limited evidence
The largest, best-controlled trial found no weight or fat loss beyond placebo, and the ingredient has a documented signal for severe liver injury.
- Green Tea Extract (EGCG) Limited evidence
The Cochrane review found essentially no weight loss, and concentrated EGCG is one of the best-documented causes of supplement-induced liver injury.
- Green Coffee Bean Extract Limited evidence
Its headline trial was retracted, and a meta-analysis of 16 trials found no significant change in body weight.
- Raspberry Ketones Limited evidence
There is no published randomised trial of raspberry ketone alone in humans; the case rests on rodent doses far above what supplements supply.
- Glucomannan Limited evidence
The best meta-analysis found no significant weight difference versus placebo, and this fibre has caused choking and oesophageal and intestinal obstruction.
- Fat Burner Formulas Limited evidence
Systematic reviews find no clinically meaningful weight loss, the small effect that exists comes from caffeine, and the category accounts for a disproportionate share of supplement-related emergency visits and liver injury.
Our verdict
Meal replacement shakes, used for one or two meals a day within a calorie deficit, are the only pick with strong evidence. Everything else adds a kilogram or so at best, and garcinia, green tea extract and fat burner formulas are not worth the money or the liver risk.