Weight loss pills: what is actually proven
This page has not yet been reviewed by a credentialed medical professional. It is educational and is not medical advice.
Three prescription pills have large, placebo-controlled trials behind them. Here is what each one found.
| Pill | Avg. loss (highest dose) | Placebo | Trial |
|---|---|---|---|
| Semaglutide pill Wegovy pill | -13.6% (25 mg) | -2.2% | OASIS 4 n=307, 64 wk |
| Orforglipron Foundayo | -11.2% (36 mg) | -2.1% | ATTAIN-1 n=3,127, 72 wk |
| Phentermine / topiramate Qsymia | -9.8% (15 mg / 92 mg) | -1.2% | CONQUER n=2,487, 56 wk |
Semaglutide pill
Taken on an empty stomach with a small sip of water, with a wait before eating. Gastrointestinal events were more common than placebo (74.0% vs 42.2%). A smaller trial than the injectables.
US status: FDA-approved for chronic weight management (December 2025), per news reports and company statements; check the FDA label.
Orforglipron
A small-molecule (non-peptide) pill. Discontinuation due to adverse events was 5.3 to 10.3% across doses vs 2.7% on placebo.
US status: FDA-approved (April 2026), per news reports and company statements; check the FDA label.
Phentermine / topiramate
An older oral option that is not a peptide drug. Prescribing information carries important cautions (for example, pregnancy risk with topiramate); read the full label.
US status: FDA-approved prescription drug.
FAQ
Is there a weight loss pill that actually works?
Yes, several prescription pills have positive placebo-controlled phase 3 trials: oral semaglutide 25 mg (-13.6% at 64 weeks), orforglipron 36 mg (-11.2% at 72 weeks) and phentermine/topiramate (-9.8% at 56 weeks). All are prescription-only.
Are over-the-counter weight loss pills effective?
This site covers prescription drugs with phase 3 trials. Supplements sold as "weight loss pills" are not held to the same evidence standard and are not covered here.
Are weight loss pills as strong as the injections?
In their separate trials, the pills produced less average weight loss than tirzepatide (-20.9%) or injectable semaglutide (-14.9%), though the trials are not directly comparable.
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