Ibutamoren Mesylate

Ibutamoren mesylate is an orally active growth hormone secretagogue that stimulates the release of growth hormone from the pituitary gland by mimicking the actions of the endogenous hormone ghrelin.

Brief glance

The primary outcome is Performance, but it's also used for Anti-Aging, Metabolic. This compound is considered a Small Molecule. It is also known as MK-677, Ibutamoren. It is not currently indicated as compoundable in 503A pharmacies. It is not listed under a DEA schedule.

Overview

Ibutamoren Mesylate (MK-677) is a potent, orally active, non-peptide growth hormone secretagogue that stimulates GH and IGF-1 release via the ghrelin receptor. It increases lean body mass, bone mineral density, and may aid muscle preservation and sleep quality in studies. Research shows sustained GH elevation without significant rises in cortisol or prolactin.

Ibutamoren Mesylate, also known as MK-677 or MK-0677, is a potent, orally active, non-peptide agonist of the growth hormone secretagogue receptor (GHSR) and ghrelin receptor that stimulates the release of growth hormone (GH) from the pituitary gland. It increases plasma GH and insulin-like growth factor-1 (IGF-1) levels, leading to gains in lean body mass, muscle mass, and bone mineral density without significantly raising prolactin or cortisol. Studies in animals and humans have demonstrated its potential for treating GH deficiency, frailty, osteoporosis, and muscle wasting, with additional benefits like improved sleep quality and wound healing. Long-term administration sustains these effects, though it does not elevate GH or IGF-1 in cerebrospinal fluid due to the blood-brain barrier.

Benefits

Ibutamoren mesylate is a nonpeptide growth hormone secretagogue that stimulates GH release through a pituitary and hypothalamic receptor distinct from the GH-releasing hormone receptor.¹ Short-term administration of ibutamoren mesylate increases serum growth hormone, insulin-like growth factor I (IGF-I), and IGF-binding protein 3 (IGFBP-3) levels in children with growth hormone deficiency, with increases in GH peak concentration and IGF-I documented on day 15 of treatment.¹ The compound is orally active and has demonstrated therapeutic potential in addressing growth hormone deficiency across pediatric and adult populations, including elderly adults, where it has been shown to increase GH and IGF-1 levels to those observed in healthy young adults without serious adverse effects.² Clinical studies indicate that ibutamoren mesylate increases lean body mass and bone mineral density in various populations including obese individuals, older adults, and post-menopausal women, supporting its investigation as a potential treatment for frailty and reduced bone density in aging populations.²,³ Additionally, ibutamoren mesylate has been shown to improve sleep architecture, increasing rapid eye movement sleep and slow-wave sleep in both younger and older subjects.³ These effects on growth hormone and IGF-1 are achieved without significant alterations to prolactin, thyroid hormones, or cortisol levels in growth hormone-deficient children, though glucose and insulin levels may be increased in severely GH-deficient adults.¹,²

Side effects

Ibutamoren Mesylate (MK-677) commonly causes increased appetite, water retention leading to swelling or bloating, insulin resistance with elevated blood glucose and reduced sensitivity, muscle or joint pain, numbness or tingling, and anxiety.⁴,⁵,⁶,⁷,⁸ Less common or serious effects include potential heart failure (prompting early trial termination), impacts on bone mineral density, hepatotoxicity such as transaminitis, lethargy, and long-term risks like type 2 diabetes or tumor growth from elevated IGF-1.⁴,⁵,⁶,⁹ Key safety considerations involve its lack of FDA approval, unestablished long-term safety, contraindications for those with heart, diabetes, liver, or joint issues, and risks of amplification when combined with SARMs; medical supervision and monitoring of glucose, liver enzymes, and cardiovascular health are essential.⁴,⁵,⁶,⁸

Mechanisms of action

Ibutamoren mesylate (MK-677) is a non-peptide agonist of the ghrelin receptor that stimulates growth hormone release through a mechanism distinct from traditional GH-releasing hormone receptors³. When taken orally, it activates the ghrelin receptor and increases the pulsatile release of endogenous growth hormone, mimicking the natural action of the hormone ghrelin³,¹⁰. This activation of the ghrelin receptor leads to increased circulating levels of both growth hormone and insulin-like growth factor-1 (IGF-1) without causing the adverse increases in prolactin or cortisol that occur with other growth hormone-releasing peptides¹⁰. The mechanism operates through stimulation of brain regions involved in metabolic regulation, particularly the hypothalamus and pituitary gland¹⁰. In animal studies, ibutamoren mesylate has demonstrated the ability to raise GH levels quickly, significantly, and persistently when administered orally or intravenously¹¹.