MK-677, also known as Ibutamoren, is a “growth hormone secretagogue,” a substance that stimulates the production of growth hormone. It is not approved for human use, which makes it an unapproved drug. It is also not legal for use as an ingredient in dietary supplements or any other consumer or commercial products. It can only be used for research purposes.

MK-677 is on the DoD Prohibited Dietary Supplement Ingredients List and the World Anti-Doping Agency Prohibited List. It is not legal for use.

The Food and Drug Administration (FDA) has posted warning letters to companies illegally selling products containing MK-677. These types of products are sometimes labeled as dietary supplements with a “Supplement Facts” label, as a research chemical with a “Research Facts” label, or even labeled as “For Research Use Only.”

Even though it is illegal, MK-677 is currently marketed with claims to help build muscle or increase muscle mass, decrease body fat, and increase energy. In addition, products that contain MK-677 are often combined with SARMs (or even indicate MK-677 as a SARM). SARMs are also illegal and prohibited for use.

What are the safety concerns?

A number of health risks have been associated with the use of MK-677 (Ibutamoren).

  • FDA lists Ibutamoren as an ingredient that “…poses significant safety risks due to the potential for congestive heart failure in certain patients.” A clinical trial was stopped early due to concerns that Ibutamoren may increase the rate of heart failure.
  • Ibutamoren is listed in the Australian Poisons Standard. The long-term safety is not established and the potential adverse effects “…may include those associated with the administration of growth hormones and the potential for downstream health effects such as cardiovascular and hormonal effects.”
  • MK-677 has also been reported to negatively impact bone and bone mineral density, increase fasting blood glucose levels, heighten the risk of hyperglycemia, and affect insulin sensitivity.
  • Other side effects include anxiety, diarrhea, increased fluid retention and swelling, increased hunger, muscle or joint pain, numbness, and nausea.
  • When combined with SARMs, MK-677 could negatively impact serum lipids, liver enzymes, testosterone levels, or worse. SARMs (on their own) are known to be associated with serious safety concerns, including the potential to increase the risk of heart attack or stroke and life-threatening reactions such as liver damage.

Can MK-677 negatively affect a Service Member’s career?

Not only is use of MK-677 a health risk, but it could adversely affect a career.

  • MK-677 is prohibited for use in the military and is on the DoD Prohibited Dietary Supplement Ingredients List and the World Anti-Doping Agency Prohibited List. Therefore, Service Members should not use any products with this ingredient.


Related readings

SARMs: What’s the harm?


Posted 23 February 2024


Adunsky, A., Chandler, J., Heyden, N., Lutkiewicz, J., Scott, B. B., Berd, Y., . . . Papanicolaou, D. A. (2011). MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: A multicenter, randomized, placebo-controlled phase IIb study. Archives of Gerontology and Geriatrics, 53(2), 183–189. doi:10.1016/j.archger.2010.10.004

Bach, M. A., Rockwood, K., Zetterberg, C., Thamsborg, G., Hébert, R., Devogelaer, J., . . . Fuh, V. (2004). The effects of MK‐0677, an oral growth hormone secretagogue, in patients with hip fracture. Journal of the American Geriatrics Society, 52(4), 516–523. doi:10.1111/j.1532-5415.2004.52156.x

Camiña, J. P., Carreira, M. C., Micic, D., Pombo, M., Kelestimur, F., Dieguez, C., & Casanueva, F. F. (2003). Regulation of ghrelin secretion and action. Endocrine, 22(1), 5–12. doi:10.1385/endo:22:1:5

Campbell, G. A., Patrie, J. T., Gaylinn, B. D., Thorner, M. O., & Bolton, W. K. (2018). Oral ghrelin receptor agonist MK-0677 increases serum insulin-like growth factor 1 in hemodialysis patients: A randomized blinded study*. Nephrology Dialysis Transplantation, 33(3), 523–530. doi:10.1093/ndt/gfw474

Cardaci, T. D., Machek, S. B., Wilburn, D. T., Heileson, J. L., Harris, D. R., Cintineo, H. P., & Willoughby, D. S. (2022). LGD‐4033 and MK‐677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report. Experimental Physiology, 107(12), 1467–1476. doi:10.1113/ep090741

Chapman, I. M., Bach, M. A., Van Cauter, E., Farmer, M., Krupa, D., Taylor, A. M., . . . Thorner, M. O. (1996). Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects. The Journal of Clinical Endocrinology & Metabolism, 81(12), 4249–4257. doi:10.1210/jcem.81.12.8954023

Codner, E., Cassorla, F., Tiulpakov, A. N., Mericq, M. V., Avila, A., Pescovitz, O. H., . . . Murphy, G. (2001). Effects of oral administration of ibutamoren mesylate, a nonpeptide growth hormone secretagogue, on the growth hormone–insulin‐like growth factor I axis in growth hormone–deficient children. Clinical Pharmacology & Therapeutics, 70(1), 91–98. doi:10.1067/mcp.2001.116514

Efimenko, I. V., Valancy, D., Dubin, J. M., & Ramasamy, R. (2021). Adverse effects and potential benefits among selective androgen receptor modulators users: A cross-sectional survey. International Journal of Impotence Research, 34(8), 757–761. doi:10.1038/s41443-021-00465-0

Holt, R. I. G., Erotokritou-Mulligan, I., & Sönksen, P. H. (2009). The history of doping and growth hormone abuse in sport. Growth Hormone & IGF Research, 19(4), 320–326. doi:10.1016/j.ghir.2009.04.009

Meyer, R. M., Burgos-Robles, A., Liu, E., Correia, S. S., & Goosens, K. A. (2013). A ghrelin–growth hormone axis drives stress-induced vulnerability to enhanced fear. Molecular Psychiatry, 19(12), 1284–1294. doi:10.1038/mp.2013.135

Murphy, M. G., Weiss, S., McClung, M., Schnitzer, T., Cerchio, K., Connor, J., . . . Gertz, B. J. (2001). Effect of Alendronate and MK-677 (a Growth Hormone Secretagogue), Individually and in Combination, on Markers of Bone Turnover and Bone Mineral Density in Postmenopausal Osteoporotic Women1. The Journal of Clinical Endocrinology & Metabolism, 86(3), 1116-1125. doi:10.1210/jcem.86.3.7294

Nass, R., Pezzoli, S. S., Oliveri, M. C., Patrie, J. T., Harrell, F. E., Clasey, J. L., . . . Thorner, M. O. (2008). Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults. Annals of Internal Medicine, 149(9). doi:10.7326/0003-4819-149-9-200811040-00003

Sevigny, J. J., Ryan, J. M., van Dyck, C. H., Peng, Y., Lines, C. R., & Nessly, M. L. (2008). Growth hormone secretagogue MK-677. Neurology, 71(21), 1702–1708. doi:10.1212/01.wnl.0000335163.88054.e7

Sigalos, J. T., & Pastuszak, A. W. (2018). The safety and efficacy of growth hormone secretagogues. Sexual Medicine Reviews, 6(1), 45–53. doi:10.1016/j.sxmr.2017.02.004

Sinha, D. K., Balasubramanian, A., Tatem, A. J., Rivera-Mirabal, J., Yu, J., Kovac, J., . . . Lipshultz, L. I. (2020). Beyond the androgen receptor: The role of growth hormone secretagogues in the modern management of body composition in hypogonadal males. Translational Andrology and Urology, 9(S2), S149–S159. doi:10.21037/tau.2019.11.30

U.S. Food & Drug Administration. (2021). WARNING LETTER: Umbrella.  from

U.S. Food & Drug Administration. (2022). WARNING LETTER: Elite Supplement Center LLC and Elite Training Facility LLC.  from

U.S. Food & Drug Administration. (2023). WARNING LETTER: Warrior Labz SARMS.  from

U.S. Food & Drug Administration. (2023). Safety risks associated with certain bulk drug substances nominated for use in compounding.  from