Tirzepatide

top pick

Also seen as: Tirzapeptide, Mounjaro, Zepbound, tirz, LY3298176

The Dose Guy’s verdict

Aug 28, 2026
4 sources

The best weight-loss compound with an FDA approval behind it. Two receptors, one of the deepest trial programs in the class, and a smoother ride than retatrutide. If you want the surest thing, or you’re already fairly lean and want the last stretch handled cleanly, this is the one. Retatrutide out-cuts it in a heavy loss, but tirzepatide has the certainty and the longest safety trail.

Would I take it?Yes, the proven road.

What it is

Tirzepatide is a dual agonist: it hits both the GIP and GLP-1 receptors, where semaglutide only works through GLP-1. The GLP-1 side is the familiar machinery, appetite drops, the stomach slows, food noise fades. GIP’s exact role is still being debated, but the clinical result is not: the dual approach consistently outperforms GLP-1 alone. Eli Lilly ran one of the largest obesity trial programs in history behind it.

Semaglutide proved one receptor could work. Tirzepatide proved two receptors could work better, and the data behind that claim is not close. Retatrutide pushes the ceiling higher still with a third receptor, but tirzepatide owns the most clinical mileage in the family.

What the research shows

The trial base is enormous, and the numbers hold across populations, durations, and endpoints:

SURMOUNT-1 at 72 weeks: mean weight loss of 15.0% with 5 mg, 19.5% with 10 mg, and 20.9% with 15 mg, versus 3.1% with placebo.NEJM 2022 · phase 3 · n=2539

SURPASS-2, head to head with semaglutide 1 mg in type 2 diabetes: tirzepatide at 5, 10, and 15 mg beat semaglutide on weight by 1.9, 3.6, and 5.5 kg at 40 weeks.NEJM 2021 · phase 3 · n=1879

SURMOUNT-4, the withdrawal trial: participants who lost 20.9% in a 36-week lead-in kept losing on tirzepatide, while the placebo switch group regained 14.0%. At week 88, 89.5% still on tirzepatide held at least 80% of their lead-in loss, versus 16.6% on placebo.JAMA 2024 · phase 3 · n=670

SUMMIT, in obesity with heart failure: cardiovascular death or worsening heart failure in 9.9% on tirzepatide versus 15.3% on placebo, hazard ratio 0.62.NEJM 2025 · phase 3 · n=731

Realistic protocols

Dose to your hunger, not to a calendar. The right dose is the lowest one that keeps appetite quiet and weight moving. Start at 2.5 mg once a week, subcutaneously. If appetite is controlled there, stay there. Step up only when real hunger returns, and give each new dose about a month before judging it, because blood levels keep building for weeks after a raise. The approved steps run through 5, 7.5, 10, 12.5, and 15 mg, but most people find their number in the lower half. Chasing 15 mg for speed usually just buys worse nausea.

Two things about living on it. Alcohol: the slowed gut makes drinking feel worse than you expect, and nausea stacks badly with a drink. Most people cut back naturally, but know what you’re walking into. Second, protect your muscle. A cut this effective will take lean mass with it if you let it, so keep protein high and keep lifting the whole way down.

If appetite suppression fades after months at a stable dose, the community answer is adding a small dose of cagrilintide. It hits the amylin pathway, a different hunger circuit, and restores the signal without chasing a higher tirzepatide dose.

Start2.5 mg/wkOnce weekly, sub-q. The clinical starting dose.

Holdyour doseIf hunger stays quiet and weight is moving, stay.

Raise+1–2 mgOnly when real hunger returns. Give each step a month.

Ceiling15 mg/wkApproved max. Most people find their dose well before it.