MK-677 (Ibutamoren)
Also known as: Ibutamoren · MK677 · Nutrobal
A non-peptide, orally active growth hormone secretagogue that mimics ghrelin, significantly elevating GH and IGF-1 levels. Unique in being orally bioavailable.
Mechanism of Action
MK-677 is a selective ghrelin receptor agonist (GHS-R1a) that stimulates the pituitary gland to release growth hormone without affecting cortisol. It increases both GH pulse amplitude and IGF-1 levels.
Amino Acid Sequence (0 AAs)
N/A (non-peptide)
Benefits
- Significantly increases GH and IGF-1 levels
- Promotes lean muscle mass and strength
- Enhances fat metabolism
- Markedly improves sleep quality
- Increases appetite
- Potential bone density improvements
- Improved skin and hair quality
Side Effects & Risks
- Increased appetite
- Water retention and bloating
- Lethargy or fatigue
- Potential insulin resistance
- Increased fasting glucose
- Tingling in hands/feet
Where to Buy MK-677 (Ibutamoren)
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From
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Storage & Reconstitution Guide
Storage Temperature
Room temperature (capsule/liquid), refrigerate if liquid
24 months (lyophilized), 28 days (reconstituted)
Reconstitution Solvent
Oral — no reconstitution needed
Swirl gently — do not shake or vortex
Handling Notes
Protect lyophilized peptide from moisture and light. Once reconstituted, keep refrigerated. Discard if solution becomes cloudy or discolored. Use insulin syringe for precise dosing.
Step-by-Step Reconstitution
Gather supplies
BAC water, insulin syringe, alcohol swabs, vial
Disinfect tops
Swab rubber stoppers of both vials with alcohol
Draw BAC water
Pull desired mL of BAC water into syringe
Inject slowly
Inject BAC water down the side of the peptide vial, swirl gently to dissolve
Preclinical Research & Reviews2
MK-677 in Elderly: Effects on Body Composition and Function
RCT in 65 elderly adults (60-81 years). MK-677 25mg/day for 12 months: lean body mass +1.9 kg vs placebo (p<0.001). GH pulsatility +97% (p<0.001). IGF-1 levels increased 55% from baseline. Fat mass: no significant change. Transient lower extremity edema in some subjects.
Primary Outcome
Lean body mass change
Fat Mass
No significant change (p=0.83)
Igf1 Increase
55% from baseline
Adverse Events
Increased appetite 56%, lower extremity edema 20%
Gh Pulsatility
+97% (p<0.001)
Lean Mass Increase
+1.9 kg vs placebo (p<0.001)
Oral Administration of Growth Hormone Secretagogue MK-677
MK-677 significantly increased GH and IGF-1 levels with sustained elevation over 12 months.
Molecular Structure
- CAS Number
- 159752-10-0
- PubChem CID
- 6450830
- Molecular Weight
- 528.67 Da
- Mol. Formula
- C27H36N4O5S
- Wikipedia
- View article
Research Protocol
- Dose Range
- 10–25 mg
- Frequency
- Once daily, oral (typically at night)
- Cycle
- 3-6 months
- Half-Life
- 24 hours
- Routes
- oral
- Notes
- Can be run continuously for 4-6 months.
Legal & Regulatory Status
Sold for research purposes only. Not for human use. Laws vary by country.
Commonly Stacked With
View all peptide stacks →External Resources
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