Description
What Is MK-677 (Ibutamoren)?
MK-677, also known as ibutamoren, is a potent, orally active growth hormone secretagogue that mimics the signaling of ghrelin, the endogenous hunger hormone, at the growth hormone secretagogue receptor (GHS-R1a). Unlike exogenous growth hormone injections, MK-677 boosts the pituitary gland to increase pulsatile secretion of endogenous growth hormone (GH) and insulin-like growth factor 1 (IGF-1) without suppressing the hypothalamic-pituitary axis.
First developed by Merck in the late 1990s, ibutamoren has been studied extensively in clinical trials for age-related muscle wasting, bone density loss, sleep quality gain, and body control. Its oral uptake and long elimination half-life of about 24 hours make it one of the most convenient GH secretagogues available for research uses. MK-677 remains a non-peptide compound, distinguishing it structurally from GHRPs such as GHRP-6 and hexarelin, and offering superior shelf life compared to injectable secretagogues.
Key Features and Specifications
| Specification |
Detail |
| Product Name |
MK-677 (Ibutamoren) |
| Dosage |
10 mg per capsule |
| Quantity |
60 capsules per bottle |
| Form |
Oral capsule |
| CAS Number |
159752-10-0 |
| Cell-level Formula |
C27H36N4O5S |
| Cell-level Weight |
528.66 g/mol |
| Purity |
≥99% (HPLC verified) |
| Testing |
Third-party HPLC and MS test |
| Storage |
Room heat, cool dry place, away from light |
| Classification |
Growth hormone secretagogue (non-peptide) |
Mechanism of Action: How MK-677 Works
MK-677 functions as a ghrelin receptor agonist, binding to GHS-R1a in the hypothalamus and pituitary gland. This binding triggers a signaling cascade that amplifies the natural pulsatile release of growth hormone from somatotroph cells. Importantly, ibutamoren increases GH secretion without greatly elevating cortisol, a key differentiator from many other secretagogues that can disrupt adrenal function.
The compound elevates circulating GH levels by about 40 to 80 percent at standard research doses, with corresponding increases in IGF-1 of 39 to 89 percent saw over 2 to 12 weeks of continuous use. MK-677 also enhances REM sleep duration by tuning GH secretion patterns during the early phases of the sleep cycle, a mechanism that has drawn interest from researchers studying age-related sleep architecture decline.
Unlike direct GH use, ibutamoren preserves the natural feedback loops between GH, IGF-1, and somatostatin, meaning the body retains its power to regulate secretion amplitude. This characteristic makes it especially valuable in longitudinal research protocols where keeping natural signaling patterns is essential.
Reported Research Applications and Benefits
Peer-reviewed studies studying MK-677 have documented several areas of interest that continue to drive its use in lab and translational research settings. Growth hormone rise research represents the main use, with ibutamoren consistently showing the power to raise GH and IGF-1 levels across diverse populations including elderly subjects, obese people, and those with relative GH deficiency.
Bone mineral density research has shown that MK-677 increases markers of bone turnover, including osteocalcin and type I collagen cross-linked C-telopeptide, suggesting possible uses in osteoporosis and fracture healing models. A two-year clinical study in postmenopausal women showed major increases in femoral neck bone mineral density after 12 months of daily use.
Body makeup studies show that ibutamoren promotes lean mass accretion while reducing adipose tissue buildup, effects attributed to the anabolic properties of sustained GH and IGF-1 rise. Sleep quality research has revealed that MK-677 increases Stage IV sleep duration by about 50 percent and REM sleep duration by roughly 20 percent, effects that persist even during prolonged use periods.
MK-677 Dosage Information for Research
| Protocol |
Dosage |
Duration |
Notes |
| Standard research dose |
10–25 mg/day |
8–12 weeks |
Most often studied range |
| Beginner protocol |
10 mg/day |
8 weeks |
Assess personal response |
| Advanced protocol |
25 mg/day |
12–16 weeks |
Used in clinical trials |
| Timing |
Once daily, evening |
— |
Aligns with natural GH pulse |
MK-677 is often gave once daily in the evening to coincide with the natural nocturnal growth hormone pulse. Its 24-hour half-life ensures stable plasma levels throughout the dosing interval. Research protocols often note that GH and IGF-1 levels reach a steady state within one to two weeks of continuous daily dosing, with peak IGF-1 rise often saw between weeks four and eight.
MK-677 vs Sermorelin: Key Differences
| Parameter |
MK-677 (Ibutamoren) |
Sermorelin |
| Class |
Ghrelin receptor agonist |
GHRH analog |
| Route |
Oral (capsule) |
Under-skin injection |
| Half-life |
~24 hours |
~10–20 minutes |
| GH rise |
40–80% increase |
20–40% increase |
| IGF-1 rise |
39–89% increase |
15–35% increase |
| Cortisol impact |
Minimal |
Minimal |
| Convenience |
Once daily oral capsule |
Daily injection needed |
| Storage |
Room heat |
Needs refrigeration |
Storage and Handling Instructions
Store MK-677 capsules at controlled room heat between 20°C and 25°C (68°F to 77°F) in the original sealed container. Keep the product in a cool, dry environment away from direct sunlight, too much heat, and moisture. Capsules should remain in their original packaging until use to keep shelf life. Under proper storage conditions, MK-677 capsules keep full potency for a minimum of 24 months from the date of manufacture. Do not freeze.
Why Choose PrymaLab MK-677 Ibutamoren Capsules
Every batch of PrymaLab MK-677 undergoes rigorous third-party testing by independent, accredited laboratories using high-performance liquid chromatography (HPLC) and mass spectrometry (MS) to verify identity, purity, and potency. Each order ships with a batch-specific Certificate of Test (COA) documenting ≥99% purity, absence of heavy metals, residual solvents, and microbial contaminants.
PrymaLab uses pharmaceutical-grade encapsulation processes to ensure precise 10 mg dosing in each capsule, removing the variability common with liquid forms. Our GMP-compliant manufacturing and full lot traceability provide the consistency and reliability that serious research demands. Free priority shipping is included on all domestic orders.
Frequently Asked Questions About MK-677
What is the recommended MK-677 dosage for beginners?
Most published research protocols begin with 10 mg per day gave as a single oral dose in the evening. This starting dose allows researchers to assess personal subject response before considering dose escalation to 25 mg per day, which represents the most often studied dose in clinical trials. The 24-hour half-life permits once-daily dosing.
How long does it take for MK-677 to elevate GH and IGF-1 levels?
Growth hormone levels often increase within the first dose, with acute elevations measurable within two to four hours of use. IGF-1 levels need longer to reach steady state, often achieving peak rise between weeks four and eight of continuous daily dosing. Consistent use is essential for sustained natural effects.
Does MK-677 suppress natural growth hormone production?
MK-677 does not suppress endogenous GH production because it works by amplifying the body’s own pulsatile GH release mechanism rather than introducing exogenous hormone. The hypothalamic-pituitary feedback axis remains intact, meaning natural control processes continue to function during and after use.
How does MK-677 compare to injectable GH secretagogues like GHRP-6?
MK-677 offers the convenience of oral use with a 24-hour half-life, compared to GHRP-6 which needs multiple daily under-skin injections and has a half-life of about 15 to 20 minutes. Both compounds boost GH release, but ibutamoren provides more stable plasma levels and does not need mixing or cold chain storage.
What is the half-life of MK-677 (ibutamoren)?
The ibutamoren elimination half-life is about 24 hours based on pharmacokinetic data from clinical studies. This extended half-life supports once-daily oral dosing and keeps consistent GH secretagogue activity throughout the 24-hour period, aligning with natural circadian GH pulsatility patterns.
Quality Assurance and Testing
PrymaLab keeps a zero-compromise quality standard for all MK-677 products. Each production batch is tested using HPLC for purity finding and mass spectrometry for structural identity confirmation. Independent third-party laboratories conduct all testing, and results are documented in a batch-specific Certificate of Test that accompanies every order. Our quality program includes heavy metal screening, residual solvent test, microbial testing, and endotoxin evaluation to ensure every capsule meets pharmaceutical research-grade standards.
Research Disclaimer
MK-677 (ibutamoren) is sold strictly for laboratory research and scientific study purposes only. This product is not intended for human consumption, veterinary use, or treatment use. MK-677 has not been approved by the FDA or any control agency for medical use. Purchasers must be qualified researchers affiliated with accredited institutions or licensed research organizations. By buying this product, you confirm that it will be used exclusively in accordance with all applicable local, state, and federal regulations governing research materials.
Only logged in customers who have purchased this product may leave a review.
15 reviews for MK-677 (Ibutamoren) (10mg/capsule) 60 Capsules