MK-677 results: what to expect and when
This experimental oral drug raises growth hormone and IGF-1; risks include high blood sugar and swelling.
Also called: Ibutamoren, Ibutamoren mesylate, Ibutamoren mesilate, MK-0677, MK0677, LUM-201, L-163,191.
Growth hormone secretagogues (ghrelin receptor) · Non-peptide ghrelin-receptor agonist and growth hormone secretagogue.
- Early months: In the older-adult trial, daily MK-677 commonly increased appetite, while mild leg swelling and muscle pain were also reported.
- Within a few months: The trial reported that increased appetite faded within a few months for many participants.
- Month 12: Lean mass increased without better strength or function, and fasting blood sugar rose while insulin sensitivity fell in the older-adult trial.
An older-adult trial used 25 mg by mouth daily for one year, with a second year of follow-up treatment.
34 original human research records include case reports and ongoing trials; some share participants. Phase 3 is in children, with no results yet.
Key studies
- Older adults: lean mass and glucose: Lean mass increased, but strength and function did not improve. (source)
- Hip fracture: stopped over heart failure: Most function measures did not improve; heart-failure concerns ended the trial. (source)
- Earlier hip-fracture trial: Higher IGF-1 did not establish better recovery. (source)
- Alzheimer disease: no benefit: Raising IGF-1 did not slow Alzheimer disease. (source)
- Obese men: lean mass and glucose tolerance: The trial did not show fat loss and detected impaired glucose tolerance. (source)
- Obese men: bone turnover: Secondary hormonal or bone findings do not establish health benefits. (source)
Related to MK-677 (ibutamoren)
- Ipamorelin: An experimental peptide that triggers growth hormone release.
- GHRP-2: A peptide that releases growth hormone and can increase hunger.
- GHRP-6: A peptide studied in growth hormone tests and an experimental stroke combination.
- Hexarelin: A peptide that releases growth hormone; repeated use can weaken the response.
- Retatrutide: An experimental weekly injection with phase 3 weight-loss results.
Sources
- Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act, FDA · FDA · 2026
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, FDA · FDA · 2026
- The 2026 Prohibited List, World Anti-Doping Agency · WADA · 2026
- Unapproved ibutamoren capsules (MK-677) found to contain undisclosed anabolic steroid, Therapeutic Goods Administration · 2026
- 503A Categories Update for September 2024, FDA · FDA · 2025
- October 29, 2024 Meeting of the Pharmacy Compounding Advisory Committee, FDA · 2024
- October 29, 2024 Pharmacy Compounding Advisory Committee (PCAC) Meeting, FDA · 2024
- Anaphylaxis, NHS · NHS · 2023
- Scheduling delegate's final decisions, April 2018, Therapeutic Goods Administration · 2018
- Evaluation and treatment of adult growth hormone deficiency: an Endocrine Society clinical practice guideline., Molitch ME et al. · The Journal of clinical endocrinology and metabolism · 2011
- EU/3/17/1882 - orphan designation for treatment of growth hormone deficiency, European Medicines Agency
- Information on Select Dietary Supplement Ingredients and Other Substances, FDA
- Search Orphan Drug Designations and Approvals, FDA · FDA
- Supply unlicensed medicinal products (specials), MHRA · MHRA
- Unauthorized workout supplements may pose serious health risks, Health Canada
Sources checked: 2026-10-18.
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