General Description

MK-677, an orally active non-peptide growth hormone, stimulates GH release without affecting cortisol levels. It has shown to increase growth hormone and IGF-1 production, promoting healing, muscle growth, and fat oxidation. Applications include anti-aging and performance enhancement for athletes. While generally safe, limited long-term data is available. One study reported higher congestive heart failure incidence in elderly patients, possibly due to baseline blood pressures. Another observed more side effects in the MK-677 group. Safety data on malignancy and mortality rates are lacking. In conclusion, while MK-677 has promising benefits, further research is needed to fully understand its safety profile.

Figure 1. Capsules of MK-677

Activities

MK-677 is an orally active non-peptide growth hormone that stimulates GH release through receptors in the pituitary and hypothalamus. It acts as a secretagogue, mimicking the actions of endogenous hormones that stimulate GH without impacting cortisol levels. Unlike other SARMS, MK-677 does not suppress natural testosterone production or affect natural growth hormone production. Therefore, it does not require post-cycle therapy. MK-677 has shown to increase plasma hormones such as growth hormone and IGF-1, leading to various benefits. It inhibits growth-inhibiting receptor signaling, slows down somatostatin activity, and amplifies growth hormone signaling through GHRH. This results in increased production and release of GHRH. The positive effects of MK-677 include rapid healing of ligaments, tendons, bones, and old injuries. It helps in building lean muscle, increasing size, and promoting fat oxidation. Additionally, it aids in the relaxation of tight skin after weight loss. While it has shown promising results in enhancing growth hormone levels and providing various benefits, proper usage and monitoring are necessary to ensure safety and maximize its potential advantages. ¹

Applications

MK-677 is a non-peptide oral growth hormone that has various applications. It stimulates the release of growth hormone (GH) through receptors in the pituitary and hypothalamus, different from the growth hormone release hormone receptor. MK-677 has shown to increase GH and insulin-like growth factor 1 (IGF-1) secretion without affecting cortisol levels. One significant application of MK-677 is anti-aging. By increasing HGH and IGF-1 levels, it helps maintain youthful vitality and improves overall physical function. This can be beneficial for individuals looking to counteract the effects of aging and improve their physical appearance.  MK-677 also holds promise for athletes and bodybuilders. Its ability to stimulate growth hormone secretion can support muscle growth and fat loss, especially when combined with resistance training and a controlled diet. This suggests that MK-677 may enhance gains in strength and physique, making it a useful adjunct to traditional training methods. When used properly under the supervision of a knowledgeable healthcare provider, MK-677 can offer valuable benefits for overall health, performance, and appearance. ²

Safety

MK-677 has been studied for its efficacy and safety in various clinical trials. Overall, the available literature suggests that MK-677 is generally safe, with few serious adverse events (AEs) reported. However, it is important to note that the studies conducted on MK-677 so far have been relatively short-term and small in scale, which limits the available safety data. One study involving elderly patients recovering from hip fractures found a higher rate of congestive heart failure in the group taking ibutamoren compared to the placebo group. However, the higher incidence of CHF may have been due in part to higher baseline blood pressures in the ibutamoren group. Another study observed more patients discontinuing treatment due to clinical AEs in the ibutamoren group compared to the placebo group. There is currently no safety data available for malignancy and mortality rates in individuals taking GHS's. In summary, while the available evidence suggests that MK-677 is relatively safe, longer-term and larger-scale studies are needed to better understand its safety profile. ³

Reference

1. Murphy MG, Plunkett LM, Gertz BJ, et al. MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism. J Clin Endocrinol Metab, 1998, 83(2):320-325.

2. Murphy MG, Bach MA, Plotkin D, et al. Oral administration of the growth hormone secretagogue MK-677 increases markers of bone turnover in healthy and functionally impaired elderly adults. The MK-677 Study Group. J Bone Miner Res, 1999, 14(7):1182-1188.

3. Sigalos JT, Pastuszak AW. The Safety and Efficacy of Growth Hormone Secretagogues. Sex Med Rev, 2018, 6(1):45-53.