What Is MK-677?
MK-677 (Ibutamoren) is classified as a gh secretagogue (oral) peptide. Non-peptide ghrelin receptor (GHSR1a) agonist that stimulates prolonged, pulsatile growth hormone release from the pituitary gland. Unlike injectable GH peptides, MK-677 is orally bioavailable with a ~24-hour half-life, enabling once-daily dosing. Increases IGF-1 levels for up to 12 months without desensitization of the GH axis. Does not suppress natural GH secretion patterns or affect cortisol levels at standard doses.
It is extensively evaluated in laboratory and clinical settings for its potential to drive sustained gh/igf-1 elevation, muscle growth, improved sleep, bone density, oral dosing convenience. Researchers target MK-677 for its ability to interact with specific cellular and molecular pathways, making it a compound of significant interest across multiple therapeutic domains.
Oral GH secretagogue with extensive clinical data (2+ year RCTs). Key concern: impairs insulin sensitivity and raises fasting glucose, especially in elderly/obese populations. One hip fracture trial in elderly was stopped early due to CHF signals. WADA prohibited. Not FDA-approved. Use caution in pre-diabetic or insulin-resistant individuals.
How Does MK-677 Work?
Non-peptide ghrelin receptor (GHSR1a) agonist that stimulates prolonged, pulsatile growth hormone release from the pituitary gland. Unlike injectable GH peptides, MK-677 is orally bioavailable with a ~24-hour half-life, enabling once-daily dosing. Increases IGF-1 levels for up to 12 months without desensitization of the GH axis. Does not suppress natural GH secretion patterns or affect cortisol levels at standard doses.
At the molecular level, MK-677 operates through pathways characteristic of the GH Secretagogue (Oral) class. By interacting with target receptors and downstream signaling cascades, the compound initiates biological responses associated with sustained gh/igf-1 elevation, muscle growth, improved sleep, bone density, oral dosing convenience.
Expected Research Timeline
Weeks 2–4
Sustained IGF-1 elevation confirmed on bloodwork; improved recovery; skin quality improvement; morning puffiness from water retention
Months 2–3
Measurable fat-free mass increase (~1-2 lbs); improved bone turnover markers; hair/nail growth acceleration; monitor fasting glucose
Long-Term
2-year clinical data shows sustained IGF-1 without tachyphylaxis; continued body composition benefits; requires ongoing glucose monitoring
What Does the Research Say?
The following are key findings from peer-reviewed studies on MK-677, indexed on PubMed and equivalent databases:
[1]MK-677 increases GH and IGF-1 without altering cortisol in healthy elderly
Chapman et al. (J. Clin. Endocrinol. Metab.): 25mg daily MK-677 for 2 weeks in healthy elderly subjects restored IGF-1 and GH profiles to young adult levels without altering cortisol, prolactin, insulin, or thyroid hormones.
Evidence: moderate[2]MK-677 2-year study: sustained IGF-1 elevation and body composition effects
Nass et al. (J. Clin. Endocrinol. Metab.): 2-year RCT in 65 healthy elderly adults. 25mg/day MK-677 increased GH and IGF-1 to young adult levels, increased fat-free mass by ~1.1kg, and did not affect BMD. Notable: fasting glucose increased by ~0.3 mmol/L.
Evidence: strong[3]MK-677 increases fat-free mass in healthy obese males
Svensson et al. (J. Clin. Endocrinol. Metab.): 8-week RCT in obese males. 25mg/day MK-677 significantly increased GH secretion, IGF-1, and fat-free mass. Transient increase in appetite and mild insulin resistance noted.
Evidence: moderate[4]MK-677 reverses diet-induced nitrogen wasting
Murphy et al. (J. Clin. Endocrinol. Metab.): MK-677 reversed diet-induced nitrogen wasting in healthy young volunteers on caloric restriction, demonstrating potent anti-catabolic properties.
Evidence: moderate[5]MK-677 improves sleep quality in healthy young and elderly
Copinschi et al. (Neuroendocrinology): MK-677 increased duration of stage IV (deep) sleep by 50% and REM sleep by 20% in both young and older subjects, correlating with enhanced overnight GH secretion.
Evidence: moderate[6]MK-677 increases bone turnover markers in postmenopausal women
Murphy et al. (J. Clin. Endocrinol. Metab.): 12-month study in postmenopausal women showing MK-677 (25mg/day) increased osteocalcin and bone-specific alkaline phosphatase, suggesting improved bone formation.
Evidence: moderateSafety & Side Effects
Oral GH secretagogue with extensive clinical data (2+ year RCTs). Key concern: impairs insulin sensitivity and raises fasting glucose, especially in elderly/obese populations. One hip fracture trial in elderly was stopped early due to CHF signals. WADA prohibited. Not FDA-approved. Use caution in pre-diabetic or insulin-resistant individuals.
| Side Effect | Incidence | Severity |
|---|---|---|
| Increased appetite | ~40-60% of users | moderate |
| Water retention / bloating | ~30% of users | moderate |
| Insulin resistance / elevated fasting glucose | ~15-25% of users | moderate |
| Lethargy / drowsiness | ~15% of users | mild |
| Numbness / tingling (paresthesia) | ~8% of users | mild |
| Joint pain | ~5% of users | mild |
FDA Status: Not Approved for Human Therapeutic Use
MK-677 is not currently FDA-approved for human use. It is available for research purposes only. Always consult a licensed healthcare provider.
How Is MK-677 Used?
Route
Oral
Dose Range
12500–12500 mcg
Frequency
7x/wk
Cycle
12–12 wk
Timing: Pre-bed (optimizes sleep + GH surge)
Notes: Standard dose: 10-25mg once daily. Oral capsule or liquid. Start at 10mg to assess appetite increase and glucose response. Pre-bed dosing leverages natural GH pulse. 5-on/2-off cycles used to manage appetite and insulin sensitivity.
All dosing information reflects parameters reported in published research literature and is not intended as clinical guidance. Usage of any peptide should be supervised by a qualified healthcare professional.
MK-677 vs. Related Compounds
| Compound | Primary Use |
|---|---|
| MK-677(this page) | Sustained GH/IGF-1 elevation, muscle growth, improved sleep, bone density, oral dosing convenience |
| CJC-1295 | Muscle growth, fat loss, recovery |
| DSIP | Improved sleep quality, stress reduction |
| Sermorelin | Muscle growth, recovery, sleep, anti-aging |
Where to Source MK-677 for Research
Purchasing ultra-high purity, laboratory-grade peptides is critical for verifiable research. We only recommend vendors providing independent, third-party HPLC Certificates of Analysis (COA).
Disclosure: PeptiDex may earn a commission from purchases. This does not affect our recommendations. We exclusively feature vendors that pass our strict quality verification protocols.
Frequently Asked Questions
What is MK-677?
MK-677 is a gh secretagogue (oral) peptide. Non-peptide ghrelin receptor (GHSR1a) agonist that stimulates prolonged, pulsatile growth hormone release from the pituitary gland. Unlike injectable GH peptides, MK-677 is orally bioavailable with a ~24-hour half-life, enabling once-daily dosing. Increases IGF-1 levels for up to 12 months without desensitization of the GH axis. Does not suppress natural GH secretion patterns or affect cortisol levels at standard doses.
What are the primary research benefits of MK-677?
Published research identifies primary mechanisms targeting: Sustained GH/IGF-1 elevation, muscle growth, improved sleep, bone density, oral dosing convenience. These findings come from 6+ peer-reviewed studies indexed in our database.
What is the half-life of MK-677?
In published pharmacokinetic data, MK-677 demonstrates a half-life of approximately 24 hours.
Is MK-677 FDA approved?
MK-677 is not currently FDA-approved for human therapeutic use. It is classified as a research compound and is studied under investigational protocols. Always consult a healthcare provider.
What are common side effects of MK-677?
Reported side effects in published literature include Increased appetite (~40-60% of users), Water retention / bloating (~30% of users), Insulin resistance / elevated fasting glucose (~15-25% of users), Lethargy / drowsiness (~15% of users), Numbness / tingling (paresthesia) (~8% of users), Joint pain (~5% of users). Most are classified as moderate in severity.
How is MK-677 administered?
In research settings, MK-677 is typically administered via Oral. Standard dose: 10-25mg once daily. Oral capsule or liquid. Start at 10mg to assess appetite increase and glucose response. Pre-bed dosing leverages natural GH pulse. 5-on/2-off cycles used to manage appetite and insulin sensitivity.
Sources
- MK-677 increases GH and IGF-1 without altering cortisol in healthy elderly. View on PubMed
- MK-677 2-year study: sustained IGF-1 elevation and body composition effects. View on PubMed
- MK-677 increases fat-free mass in healthy obese males. View on PubMed
- MK-677 reverses diet-induced nitrogen wasting. View on PubMed
- MK-677 improves sleep quality in healthy young and elderly. View on PubMed
- MK-677 increases bone turnover markers in postmenopausal women. View on PubMed