What is tirzepatide?
Tirzepatide activates two gut-hormone receptors at once — GLP-1 and GIP — which is why researchers call it a dual agonist and why it has drawn so much attention in weight and metabolic research.
This page collects everything we've written about it: how it works, dosing and titration, side effects, comparisons with semaglutide, and what compounded tirzepatide involves. Compounded tirzepatide is available only by prescription; a licensed provider reviews every request, and not everyone qualifies. Start with the mechanism article if you're new — the rest builds on it.
16 articles on this topic
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Is Tirzepatide a Peptide? A Clear Answer
Yes. Tirzepatide is a 39-amino-acid synthetic peptide, and it is also a dual GIP/GLP-1 receptor agonist. Those labels describe its structure and its action, respectively.
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Tirzepatide Units to Mg: The Safe Conversion
Tirzepatide units to mg is not a fixed conversion. On a U-100 syringe, 20 units is 0.2 mL; the milligram amount depends on the vial concentration.
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Does Tirzepatide Cause Hair Loss?
In the pivotal 72-week obesity trials, hair loss was reported by about 3%–7% of tirzepatide groups versus about 1% with placebo. Weight-loss-related telogen effluvium is the leading explanation, but a direct drug effect has not been ruled out.
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How Does Tirzepatide Work? The Dual Mechanism
Tirzepatide activates two nutrient-sensitive hormone receptors, not one. The result is a linked set of effects on insulin, glucagon, stomach emptying and the signals that shape hunger and fullness.
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Where to Inject Tirzepatide: Abdomen, Thigh, Arm
Current Zepbound and Mounjaro labels name three subcutaneous areas: the abdomen, thigh, and back of the upper arm. This overview does not replace the product-specific instructions from the prescriber and dispensing pharmacy.
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Compounded Tirzepatide: Is It Legal in 2026?
Compounded tirzepatide can be prescribed in limited, patient-specific circumstances, but the shortage-era rules changed. Here is the line between section 503A compounding, brand-name products and grey-market vials as of August 2026.
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Tirzepatide Brand Names: Mounjaro and Zepbound
The two U.S. tirzepatide brand names are Mounjaro and Zepbound, both made by Eli Lilly. They contain the same active ingredient but carry different approved uses; compounded tirzepatide is not a brand.
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Get Tirzepatide Online With a Prescription
Getting tirzepatide online still requires a prescription. The legitimate routes all end at the same checkpoint: an authorized clinician reviews your case before a licensed pharmacy dispenses anything.
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Semaglutide Pill vs Injection: What Exists
There is a semaglutide pill. There is no tirzepatide pill, and there is unlikely to be one. Understanding why comes down to what happens to a 39-amino-acid peptide in your stomach.
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Microdosing Tirzepatide: What It Means
No trial has ever tested it, and the term has no clinical definition. That does not make it unreasonable — but it does change what you can honestly expect from it.
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Tirzepatide Cost: What You Actually Pay
The brand-name list price runs about $1,086 a month. Almost nobody pays it — and the gap between that number and what you are actually quoted is where most of the confusion lives.
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Tirzepatide Dosage and the Titration Ladder
Every tirzepatide dose ladder starts at 2.5 mg and climbs in 2.5 mg steps no sooner than every four weeks. Understanding why that interval exists tells you most of what you need to know about your own schedule.
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Tirzepatide Side Effects, From Common to Rare
Gastrointestinal effects are the ones almost everyone asks about — and across the tirzepatide dose range they affect 39% to 49% of people, concentrated in the weeks when the dose is going up.
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Tirzepatide vs Semaglutide: The Head-to-Head Data
In the SURMOUNT-5 trial, adults with obesity but without diabetes averaged 20.2% body-weight loss on tirzepatide and 13.7% on semaglutide over 72 weeks.
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Tirzepatide Clinical Trials: What the Data Show
Two phase 3 programmes, a cardiovascular outcome trial that reported in December 2025, and more than 18,000 participants — here is what the published evidence actually shows, dose by dose.
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Semaglutide Weight Loss Results: 14.9% in 68 Weeks
Adults with obesity in the 68-week STEP 1 trial lost an average of 14.9% of their body weight on weekly semaglutide, while the placebo group averaged 2.4%.