MK-677, also known as Ibutamoren or Nutrabol, is a potent growth hormone secretagogue studied extensively for its ability to significantly increase circulating levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) without altering cortisol levels. As a non-peptide, orally active compound, it is of great interest in research involving muscle development, recovery, sleep improvement, body composition, and neurocognitive support.

Unlike direct GH injection protocols, MK-677 promotes the natural secretion of GH by stimulating the ghrelin receptor (GHS-R1a) in the hypothalamus. Because of this, researchers often use MK-677 as a model for exploring long-term growth hormone enhancement, age-related decline in GH, and recovery in trauma or injury settings.

This product is intended for laboratory research only. It is not approved for human consumption and must not be used as a supplement or therapeutic agent.

What is MK-677?

MK-677 (Ibutamoren) is a selective, orally bioavailable agonist of the ghrelin receptor, first developed for the treatment of conditions like muscle wasting and GH deficiency. As a GH secretagogue, it works by imitating the hunger hormone ghrelin and binding to the associated receptor, prompting the pituitary gland to increase GH output naturally.

This leads to a cascade effect, where IGF-1—another anabolic hormone that supports tissue regeneration, muscle growth, and metabolism—is also elevated. What makes MK-677 unique is its ability to sustain elevated GH and IGF-1 levels without suppressing natural testosterone or requiring injections.

How It Works:

MK-677 acts directly on GHS-R1a receptors in the brain. This stimulates the pituitary to secrete growth hormone, which then acts on tissues such as the liver to produce IGF-1. Studies show that MK-677 increases GH pulse amplitude without affecting frequency, creating a strong but natural rhythm of hormone production.

Importantly, MK-677 does not suppress the hypothalamic-pituitary-adrenal (HPA) axis, allowing for long-term administration in research contexts without interfering with cortisol, testosterone, or other major endocrine pathways.

Research Applications:

These use cases are strictly limited to academic and laboratory research. MK-677 is not approved for therapeutic use and is sold for non-human consumption only.

1. Muscle Growth & Preservation:

Numerous studies have shown that MK-677 improves lean body mass in both healthy individuals and those suffering from muscle-wasting diseases. In a 2-month double-blind placebo-controlled study, participants taking MK-677 showed significant increases in muscle mass and nitrogen retention, even without changes to exercise routines.

2. Injury Recovery & Tissue Regeneration:

By raising IGF-1 levels, MK-677 supports tendon, ligament, and muscle repair. This makes it a popular choice in research related to post-injury healing and rehabilitation models.

3. Fat Loss & Metabolism:

MK-677 has demonstrated body recomposition effects in several studies, notably by reducing visceral fat while simultaneously increasing lean mass. Researchers believe this is due to enhanced GH-driven lipolysis (fat breakdown) combined with improved insulin sensitivity.

4. Improved Sleep Quality:

Multiple trials report enhanced REM and deep sleep cycles with MK-677. Researchers studying sleep deprivation models often use MK-677 due to its effects on sleep architecture—specifically, increases in total sleep time and slow-wave sleep.

5. Longevity and Anti-Aging Research:

Growth hormone declines with age. MK-677 is studied for its potential to reverse age-related hormonal decline, enhance bone mineral density, support skin elasticity, and improve cognitive resilience—all key targets in longevity-focused research.

6. Bone Density and Fracture Recovery:

MK-677 increases osteoblast activity and bone turnover, leading to improvements in bone density in older adults and models of osteoporosis. A 12-month study in elderly participants showed statistically significant increases in bone mass density (BMD) and markers of bone formation.

Theoretical Benefits (Lab-Based Observations):

• Boosts GH and IGF-1 significantly within 7 days

• Enhances lean mass and reduces fat mass simultaneously

• May aid in muscle preservation during caloric restriction

• Improves skin tone, sleep depth, and subjective energy

• Increases nitrogen retention and collagen production

• Non-suppressive to testosterone or HPTA function

• Easy oral administration (no injection required)

Dosage & Experimental Design (For Research):

• Typical Experimental Range: 10mg – 25mg daily

• Cycle Length: 8–12 weeks or longer in extended trials

• Half-Life: ~24 hours (single daily dosing sufficient)

• Capsules per Bottle: 30 x 20mg

Due to its long half-life, MK-677 can be administered once per day, making it ideal for long-term observation of GH/IGF-1 modulation.

Observed Side Effects (From Trials):

While MK-677 is generally well-tolerated in trials, some studies and anecdotal research logs report:

• Increased appetite (due to ghrelin receptor activation)

• Transient insulin resistance in some subjects

• Water retention (especially facial or extremity bloating)

• Numbness or tingling in hands/feet (GH-related)

• Slight increase in prolactin (rare)

Most of these effects are dose-dependent and reversible upon cessation.

Storage Instructions:

• Keep in a cool, dry environment

• Avoid direct sunlight or heat exposure

• Seal tightly to preserve capsule stability for up to 24 months

Scientific Literature & Clinical References:

• The Journal of Clinical Endocrinology & Metabolism (2001) – MK-677 increases GH and IGF-1 in older adults

• Rejuvenation Research (2006) – Improved sleep and muscle retention

• Clinical Pharmacology & Therapeutics (1998) – Long-term effects on body composition and metabolism

Disclaimer:

MK-677 (Ibutamoren) is not a dietary supplement or medication. This compound is intended strictly for in vitro or animal testing only. It is not approved by the FDA, TGA, or EMA for human use. All product handling and disposal must follow appropriate laboratory safety protocols.