Tirzepatide
Dual GLP-1 / GIP receptor agonist
- Class
- Dual agonist
- Half-life
- ~5 days
- Route
- Subcutaneous (SubQ)
- Cadence
- Weekly
- Evidence
- Human clinical trials
Overview
Tirzepatide is the closest thing to a one-shot weight-loss drug right now. A single weekly subcutaneous injection (the kind you do at home in your stomach or thigh), and in the biggest trial people lost about 20% of their body weight over 72 weeks. It's the same drug sold as Mounjaro for type-2 diabetes and Zepbound for weight management — same molecule, different label.
It works by hitting two gut hormones at once — GLP-1 (which makes you feel full and slows stomach emptying) and GIP (which seems to help your body handle the calories you do eat). Older drugs in this family only hit GLP-1. Hitting both gets you more weight loss and slightly better blood-sugar control than semaglutide head-to-head.
The catch: the first few months are rough for most people. Nausea, sometimes vomiting, often constipation or diarrhoea — bad enough that around 6% of trial participants quit. Slowing down the dose-ramp usually fixes it, but you should expect to feel off during the titration window.
In the SURMOUNT-5 head-to-head trial, tirzepatide produced greater weight loss than semaglutide (20.2% vs 13.7% at 72 weeks) in adults with obesity or overweight.
Safety considerations
A few of the safety signals worth knowing — the full list, with dosing context and what to monitor, is inside AIx Core.
- Black-box warning for thyroid tumours (found in rats, unclear if it happens in humans). Hard no if you or a close family member has medullary thyroid carcinoma or MEN-2.
- Pancreatitis is rare but real — if you get severe stomach pain that radiates to your back, stop and get checked.
- Gallbladder problems (stones, inflammation) are more common during rapid weight loss on any GLP-1 drug — not specific to tirzepatide, just the territory.
+ 3 more safety notes inside AIx Core →
Commonly monitored
Markers and signals people track when researching Tirzepatide.
- Body composition (DEXA or even consistent waist measurements — don't trust the scale alone)
- HbA1c — especially if you're using it for diabetes
- Lipid panel — most people see triglycerides drop substantially
- Resting heart rate (mild uptick is normal; large jumps warrant a check)
- Gallbladder symptoms — pain under your right ribs, especially after fatty meals
Frequently asked questions
What is Tirzepatide?
Dual GLP-1 / GIP receptor agonist. Tirzepatide is the closest thing to a one-shot weight-loss drug right now. A single weekly subcutaneous injection (the kind you do at home in your stomach or thigh), and in the biggest trial people lost about 20% of their body weight over 72 weeks. It's the same drug sold as Mounjaro for type-2 diabetes and Zepbound for weight management — same molecule, different label.
How is Tirzepatide administered?
Subcutaneous (SubQ), typically weekly.
What is the half-life of Tirzepatide?
~5 days — Stays in your system about a week — supports once-weekly dosing.
Is Tirzepatide approved for human use?
Tirzepatide is approved by at least one regulator for one or more indications. Use outside an approved indication is off-label and not endorsed here.
What does the evidence show for Tirzepatide?
Evidence tier: Human clinical trials. SURMOUNT-1 (Jastreboff 2022, N=2,539, 72 weeks): people on 15 mg lost an average of -20.9% body weight vs -3.1% on placebo. That's the headline number people quote.
What is commonly monitored when researching Tirzepatide?
Commonly tracked markers + signals: Body composition (DEXA or even consistent waist measurements — don't trust the scale alone), HbA1c — especially if you're using it for diabetes, Lipid panel — most people see triglycerides drop substantially, Resting heart rate (mild uptick is normal; large jumps warrant a check), Gallbladder symptoms — pain under your right ribs, especially after fatty meals.
Related compounds
Open this in AIx Core for the full picture
Mechanism breakdown, receptor pathway diagram, full safety list, monitored items, source citations, and one-tap add-to-protocol. Free with any account.