Ibutamoren
July 20, 2026
Ibutamoren
(also known as MK-677, MK-0677, LUM-201)
Ibutamoren is an orally active growth hormone secretagogue (non-peptide) that acts as a ghrelin receptor (GHS-R) agonist [1]. It mimics the effects of the endogenous peptide hormone ghrelin, stimulating growth hormone (GH) release, and may also, through the ‘ghrelin system’, affect appetite, immune function, insulin response, mood, and stress regulation [2]. In Finland, ibutamoren is classified as a medicinal substance on FIMEA’s list [3], but it is not currently a component of any approved medicine, and no regulatory authority has approved it for human use [4].
Ibutamoren in Performance- and Image-Enhancing Drugs use – why is it used?
The growth hormone-releasing properties may attract people who use performance- and image-enhancing drugs to experiment with ibutamoren. It has also been mislabelled and sold online as a SARM (selective androgen receptor modulator) [4] despite having no AR activity. In addition, ibutamoren has been found as an undeclared substance in nutritional supplements [5].
Cases in PIEDs use [6]:
- A 30-year-old man reported using a product containing 25 mg of ibutamoren, marketed under the name of “DNA Pharma SARM Ibutamoren MK-677” He reported experiencing weight loss, diarrhea, headache, and abdominal discomfort. The case information did not include details such as how long he had used the product, whether he was taking other medications, or the timing between use and symptoms.
- A man reported taking capsules marketed as “DNA Anabolics SARM MK 677” (containing ibutamoren) as a supplement intended to enhance strength. After several weeks of use, he noticed the product label actually stated it was “Not for Human Consumption, For Laboratory Use Only.” The dosage was not specified. He experienced reduced activity levels and mood changes during this period, both of which resolved after he stopped using the product.
Adverse effects and health risks
As ibutamoren is not approved for any clinical use, long-term human safety data remain limited. However, an FDA briefing document concludes that, based on available clinical data, there are serious safety concerns regarding the use of ibutamoren (mesylate). These reported and discussed adverse effects and safety concerns have included [6]:
- Congestive heart failure
- Negative impact on bone density
- Changes in blood sugar: heightened risk of hyperglycemia, increase in fasting blood glucose, decline in insulin sensitivity
- Musculoskeletal pain (muscle and joint pain)
- Liver enzyme elevations
- Edema and fluid overload
- Hyperprolactinemia
- Gastrointestinal (GI) problems
- Increased appetite
Medical use and clinical trials
No approved medical indication for any human therapeutic use.
Currently, a Phase 3 study of LUM-201 for the treatment of pediatric growth hormone deficiency (PGHD) in children is underway (Date: 20/05/2026). [7]
Mikko Lemettilä, MSc (Pharm.Sci.), A-Clinic Foundation
[1] Patchett, A. A., Nargund, R. P., Tata, J. R., Chen, M. H., Barakat, K. J., Johnston, D. B. R., Cheng, K., Chan, W. W. S., Butler, B., Hickey, G., Jacks, T., Schleim, K., Pong, S. S., Chaung, L. Y., Chen, H. Y., Frazier, E., Leung, K. H., Chiu, S. H., & Smith, R. G. (1995). Design and biological activities of L-163,191 (MK-0677): A potent, orally active growth hormone secretagogue. Proceedings of the National Academy of Sciences, 92(15), 7001–7005. https://doi.org/10.1073/pnas.92.15.7001
[2] Yanagi, S., Sato, T., Kangawa, K., & Nakazato, M. (2018). The homeostatic force of ghrelin. Cell Metabolism, 27(4), 786–804. https://doi.org/10.1016/j.cmet.2018.02.008
[3] Finnish Medicines Agency (Fimea). (2025, June 3). List of medicines. Fimea. https://fimea.fi/en/supervision/classification/list_of_medicines
[4] Van Wagoner, R. M., Eichner, A., Bhasin, S., Deuster, P. A., & Eichner, D. (2017). Chemical Composition and Labeling of Substances Marketed as Selective Androgen Receptor Modulators and Sold via the Internet. JAMA, 318(20), 2004–2010. https://doi.org/10.1001/jama.2017.17069
[5] Al-Saad, N., Aljaal, S., Alessa, J., & Santhosh, M. E. (2026). Systematic review of undeclared prohibited substances and pharmacological adulterants in dietary supplements: prevalence, detection, and risks in sport. Frontiers in sports and active living, 8, 1740663. https://doi.org/10.3389/fspor.2026.1740663
[6] U.S. Food and Drug Administration. (2024, July 3). FDA briefing document: Pharmacy Compounding Advisory Committee (PCAC) meeting – Ibutamoren mesylate. https://www.fda.gov/media/182087/download
[7] ClinicalTrials.gov. (2026). Phase 3 study of LUM-201 in children with growth hormone deficiency (Identifier No. NCT06948214). https://clinicaltrials.gov/study/NCT06948214
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