Tirzepatide
A single weekly injection that activates two gut hormone receptors, GIP and GLP-1, rather than one. Sold as Zepbound and Mounjaro by Eli Lilly.
What the trials showed
In SURMOUNT-1, adults with obesity lost an average of 19.5% of body weight on 10 mg and 20.9% on 15 mg over 72 weeks.
SURMOUNT-5 compared the two drugs directly. Participants on tirzepatide lost an average of 50.3 lb (22.8 kg); those on semaglutide lost 33.1 lb (15.0 kg).
Read the research in plain English
Explore how study populations, event definitions and counting rules shape a reported result.
- Tirzepatide study terms: how to read a decision to stop
A plain-language guide to denominators, overlapping outcomes and missing observations in a study table.
How it is dosed
Treatment starts low and steps up roughly every four weeks through 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg. The starting dose is there to let your system acclimatise — it is not a treatment dose, which is why the first weeks can feel as though little is happening.
Side effects
Nausea, diarrhoea, constipation and reflux, concentrated in the weeks after each dose increase.
Some people should not take this medication at all, and it interacts with several common prescriptions — the contraindications are here.
What it costs
Through LillyDirect self-pay, single-dose Zepbound vials at 5 mg, 7.5 mg and 10 mg have been listed at $499/month, with lower starting doses nearer $299-$349.
Compounded preparations cost less and are not FDA-approved — what that actually means.
Who dispenses it
| Dispensed by | Product | Per month | Score |
|---|---|---|---|
| Coreage Rx Best overall on true monthly cost | Compounded | $199 | 4.5 |
| SuperHealthy Rx Public offer; not independently scored | Compounded | $135 | Not scored |
| Likeness Rx Public offer; not independently scored | Compounded | $199 | Not scored |
| Trimi Lowest flat price with named pharmacies | Compounded | $125 | 4.6 |
| PlexusDx Pharmacy transparency and genetic testing | Compounded | $189 | 4.4 |
| Ozari Health Lowest advertised semaglutide price | Compounded | $125 | 4.4 |
| Fifty 410 Prepaid blocks with no subscription | Compounded | $133 | 4.2 |
| Ivím Health Unlimited clinician access | Compounded | $199 | 4 |
| Mochi Health Insurance concierge support | Compounded | $278 +$79 fee | 3.6 |
| Coby Health Multi-month value with supplies included | Compounded | $239 | 3.6 |
| Hims & Hers Widest range of formats | Compounded | $238 +$39 fee | 3.5 |
| Ro Branded medication with insurance help | FDA-approved brand | $448 +$149 fee | 3.5 |
Full comparison of Tirzepatide programmes →
Compared with Semaglutide
Read about Semaglutide → or see brand-name versus compounded.