Metabolic

Tirzepatide

Acylated peptide · GIP/GLP-1 dual agonist · 39 amino acids

FDA · APPROVED (MOUNJARO/ZEPBOUND)

Half-life

~5.0 days

Long

minsdays

Route

SubQ injection

Evidence

Approved therapeutic

Risk

Standard

Overview

Known for

Dual GLP-1/GIP agonist. FDA-approved for type 2 diabetes (Mounjaro) and weight loss (Zepbound). Powerful appetite suppression, blood sugar regulation, and fat loss. One of the most effective weight loss compounds available.

Mechanism

Dual GIP/GLP-1 agonist — mimics 2 gut hormones to reduce appetite, slow gastric emptying, improve insulin

Key facts

Format
Lyophilized powder
Mechanism targets
Classification
Authoritative
Supply & nature
ExogenousExogenous
FDA category
Approved (Mounjaro/Zepbound)

Evidence & standing

Evidence base
Approved therapeutic
Risk level
Standard
Best studies
4 references
  • Jastreboff et al. (2022) SURMOUNT-1 Phase 3 Trial. NEJM 387(3):205-216. DOI: 10.1056/NEJMoa2206038
  • Aronne et al. (2025) SURMOUNT-5 (tirz vs sema). NEJM 393(1):26-36. DOI: 10.1056/NEJMoa2416394
  • FDA Approved: Mounjaro (2022, T2D), Zepbound (2023, obesity)
  • ClinicalTrials.gov: NCT04184622

Dosage & protocol

Typical dose
2.5mg
Research range
2.5–15 mg
Cycle
Weekly injection
Onset
10 days first effects
Full effect
112 days
Half-life
~5d
~5 days (t½ 5.0d)
Protocol

Titrate: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg weekly. Increase every 4 weeks. SubQ once weekly.

Time to effects

EARLY: 1-2 weeks

FULL: 12-20 weeks

Week 1-2: Appetite suppression noticeable almost immediately, even at lowest dose. Mild nausea common (this IS the drug working).

Week 2-4: Measurable weight loss begins (1-2kg). Reduced food noise and cravings.

Week 4-8: Significant weight loss visible (3-5%+ body weight). Blood sugar improvements measurable on blood work.

Week 12-20: Approaching maximum effect at maintenance dose. 15-22% total body weight loss in clinical trials at 20-24 weeks.

Minimum commitment: 12 weeks to properly assess. Most continue 6-12+ months.

Recommended vial
  • 10mg or 15mg vials

At 2.5-5mg/wk (early titration), 10mg lasts 2-4 weeks ✓. At 10-15mg/wk maintenance, 15mg = 1-1.5 weeks ✓. Avoid 30mg+ unless at high maintenance doses.

Reference figures only

Dosing reflects published laboratory protocols and is not guidance for use in any living subject.

Safety

Reversibility
Not Reversible
Side effects

Nausea (25-33%), diarrhoea (17-23%), vomiting (7-12%), constipation (6-11%), injection site reaction (3-5%)

Interactions

Insulin/sulfonylureas (↑hypoglycaemia risk), oral contraceptives (delayed absorption), oral medications (slowed gastric emptying affects all oral drug absorption)

Do not combine
CagrilintideCagrilintide Cagrilintide 5mg + Semaglutide 5mg (Blend)Cagrilintide 5mg + Semaglutide 5mg (Blend) RetatrutideRetatrutide SemaglutideSemaglutide SurvodutideSurvodutide

Handle with research caution

  • Do NOT combine with Semaglutide or Retatrutide (stacking GLP-1 agonists = severe GI toxicity, no added benefit)
  • Do NOT combine with Survodutide or CagriSema (same class overlap)
  • Caution with insulin or sulfonylureas (hypoglycaemia risk)

Storage & handling

Lyophilised
21 days
room temp ≤30°C for up to
Reconstituted
4–6 weeks
2–8°C

Compare with related peptides

Retatrutide is the 'upgrade' — triple agonist (GLP-1/GIP/Glucagon) vs dual. Phase 3 trials show ~28.7% weight loss vs ~22% for tirzepatide. However tirzepatide is FDA-approved while retatrutide is not yet.

This compound
Tirzepatide
Tirzepatide
Retatrutide
Retatrutide
Goal
Metabolic
Metabolic
Evidence
Approved therapeutic
Clinical trial data
Risk
Standard
Standard
Half-life
~5.0 days
~6.0 days

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