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 MK-677 and Tirzepatide — mechanism, side effects, legal status, and pricing.
MK-677 (ibutamoren, MK-0677, L-163,191) is an orally active, non-peptide small-molecule growth hormone secretagogue developed by Merck in the 1990s. It is a spiropiperidine ghrelin-receptor (GHSR-1a) agonist — not a peptide and not a SARM, though it is commonly misclassified as both in grey-market retail. Merck discontinued development after mixed efficacy and adverse metabolic / cardiovascular findings; it is not FDA-approved.
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.
MK-677
Tirzepatide
Category
Legal Status
Mechanism
Half-life
Side Effects
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MK-677
No pricing data yet.
Check MK-677 prices →Tirzepatide
COA corpus from Disclosed Labs — independently tested batches only.
MK-677
5
COAs
98.3%
Avg purity
3
Labs
Tirzepatide
306
COAs
99.7%
Avg purity
15
Labs
MK-677 has meaningful human data from Merck-sponsored Phase I/II trials. Murphy et al. (JCEM 1998, PMID 9467534) showed 25 mg MK-677 reversed nitrogen wasting during caloric restriction in healthy adults. Svensson et al. (JCEM 1998, PMID 9467542) reported ~40% IGF-1 elevation, increased fat-free mass, and higher energy expenditure over 8 weeks in obese men. Copinschi et al. (Neuroendocrinology 1997, PMID 9349662) documented improved slow-wave and REM sleep in young and older adults. Nass et al. (Ann Intern Med 2008, PMID 18981485) — the pivotal 2-year randomized trial in 65 healthy older adults — restored GH and IGF-1 to young-adult levels and increased fat-free mass, but produced modest fasting glucose elevation and insulin resistance. The Adunsky et al. Phase IIb hip-fracture trial (Arch Gerontol Geriatr 2011, PMID 21067829) was stopped early after a congestive-heart-failure safety signal (4/62 ibutamoren vs 1/60 placebo). Merck discontinued development. MK-677 is commonly mislabeled as a 'SARM' in grey-market retail — it is not; it is a ghrelin-receptor agonist and oral GH secretagogue. It has never been FDA-approved.
Key references
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.
MK-677 (Performance) and Tirzepatide (Metabolic) are in different categories and target different biological pathways. This is a common pattern in multi-compound research protocols. Researchers should monitor the biomarkers from both profiles and watch for interactions listed in each compound’s contraindications. Consult a licensed healthcare provider before combining any 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