Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Tirzepatide and Retatrutide — mechanism, side effects, legal status, and pricing.
Tirzepatide is a unimolecular dual GIP and GLP-1 receptor agonist FDA-approved as Mounjaro for type 2 diabetes (2022), Zepbound for chronic weight management in adults with obesity or overweight with a weight-related comorbidity (2023), and Zepbound for moderate-to-severe obstructive sleep apnea in adults with obesity (2024). It has a half-life of approximately 5 days, allowing once-weekly subcutaneous dosing.
Tirzepatide
Retatrutide
Category
Legal Status
Mechanism
Half-life
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Tirzepatide
Retatrutide
COA corpus from Disclosed Labs — independently tested batches only.
Tirzepatide
375
COAs
99.6%
Avg purity
16
Labs
Retatrutide
455
COAs
99.7%
Avg purity
19
Labs
The SURPASS program established efficacy in type 2 diabetes, including SURPASS-2 (Frias et al., NEJM 2021), in which tirzepatide was superior to semaglutide 1 mg for A1C reduction and body weight. The SURMOUNT-1 obesity trial (Jastreboff et al., NEJM 2022) demonstrated up to approximately 20.9% mean body-weight reduction at 15 mg over 72 weeks. SURMOUNT-OSA (Malhotra et al., NEJM 2024) showed large reductions in apnea-hypopnea index in obstructive sleep apnea with obesity, supporting the 2024 FDA indication (Zepbound for moderate-to-severe OSA in adults with obesity). The SUMMIT trial (Packer et al., NEJM 2025) demonstrated a lower risk of cardiovascular death or worsening heart failure in HFpEF with obesity.
Phase 2 obesity trial (Jastreboff et al., NEJM 2023; PMID 37366315) demonstrated up to 24.2% body weight loss at 48 weeks at the 12 mg dose, exceeding both semaglutide and tirzepatide. A Phase 2 type 2 diabetes trial (Rosenstock et al., Lancet 2023; PMID 37385280) showed robust HbA1c and weight reductions vs. placebo and dulaglutide. A Phase 2a MASLD trial (Sanyal et al., Nat Med 2024; PMID 38858523) demonstrated significant reductions in hepatic steatosis driven by glucagon receptor activation. Phase 3 TRIUMPH trials are ongoing (Eli Lilly), with results expected 2025–2026. Retatrutide is NOT FDA-approved as of April 2026 — it remains investigational.
Tirzepatide and Retatrutide are both in the Metabolic category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Disclosed Labs