GLP-1 vs. Older Weight Loss Pills (Phentermine, Contrave, Qsymia)
For most patients, GLP-1 medications produce 2-4x more weight loss than older oral weight-loss drugs. Here\'s the head-to-head.
Comparison Table
| Drug | Class | Weight Loss | Form | Cost |
|---|---|---|---|---|
| Tirzepatide (Zepbound) | Dual GLP-1/GIP RA | ~21% | Weekly injection | $249-1,069/mo |
| Semaglutide (Wegovy) | GLP-1 RA | ~15% | Weekly injection | $179-1,349/mo |
| Liraglutide (Saxenda) | GLP-1 RA | ~5-8% | Daily injection | $450-1,349/mo |
| Qsymia | Phentermine + topiramate | ~10% | Daily oral | $98-200/mo |
| Contrave | Naltrexone + bupropion | ~5-9% | Daily oral | $99-650/mo |
| Phentermine | Sympathomimetic stimulant | ~3-5% | Daily oral (≤12 wks) | $15-30/mo |
| Metformin | Biguanide | ~2-3% | Daily oral | $4-15/mo |
When Non-GLP-1 Options Make Sense
- Personal/family history of medullary thyroid carcinoma → GLP-1s contraindicated
- History of pancreatitis → caution with GLP-1s
- Severe needle phobia → oral options (or wait for orforglipron 2026)
- Cost is overwhelming barrier even for compounded GLP-1 ($179/mo)
- Short-term jumpstart for ~12 weeks → phentermine
Frequently Asked Questions
Is metformin a GLP-1?
No. Metformin is a biguanide, not a GLP-1. It works by reducing liver glucose production. Some patients use both metformin and a GLP-1 together.
GLP-1 vs. phentermine?
GLP-1s produce 15-22% weight loss vs. phentermine's 3-5%. GLP-1s are also long-term safe; phentermine is approved for short-term use only (12 weeks). For sustained weight loss, GLP-1s are dramatically more effective.
GLP-1 vs. Contrave?
GLP-1s produce 15-22% weight loss; Contrave produces 5-9%. Contrave is oral and useful for patients who cannot use GLP-1s (thyroid history). For most patients, GLP-1s are stronger.
GLP-1 vs. Qsymia?
GLP-1s produce 15-22% weight loss; Qsymia produces ~10%. Qsymia is oral, has different side effects (tingling, dry mouth) and a teratogenicity warning. GLP-1s are stronger and safer for most.