Weight
MK-677
Growth
2
Amino acids
Molecular weight
Peptide
Type
MK-677 (Ibutamoren) is a non-peptide small molecule — not a true peptide — that acts as an orally active, selective agonist of the ghrelin receptor (GHS-R1a), stimulating pulsatile growth hormone release and sustained elevation of IGF-1. It has been evaluated in Phase 1/2 clinical trials for body composition, bone turnover, and GH deficiency in older adults, and is used in research for its ability to increase lean mass and bone mineral density without suppressing endogenous GH production. Its oral bioavailability (~60%) and ~24-hour half-life distinguish it from injectable GH secretagogue peptides.
Top researched benefits
Overview of MK-677
MK-677 binds selectively to the growth hormone secretagogue receptor 1a (GHS-R1a) in the hypothalamus and pituitary, mimicking ghrelin to trigger pulsatile GH secretion and downstream IGF-1 production via the GH-IGF-1 axis, without activating the negative feedback loops associated with exogenous GH administration.
growth hormone
- Restores youthful growth hormone levels in elderly subjects with 97% increase in 24-hour secretion.
- Sustained 40-72% IGF-1 elevation over extended periods.
- 20% REM increase in younger adults; 50% improvement in elderly.
body composition
- Demonstrates +2.69g/day nitrogen retention versus -8.97g/day placebo, protecting lean mass during caloric restriction.
- Increases fat-free mass with preferential lean tissue accrual.
- 15% basal metabolic rate elevation documented at 2 weeks.
bone health
- 39-45% increase in bone formation markers within 6-8 weeks.
Typical Dose
10–25mg per day orally
Frequency
once daily, preferably at night
Cycle Duration
12–16 weeks on, 4–8 weeks off
Storage
Powder/capsule: room temperature, cool dry place away from light and moisture. Liquid/reconstituted: refrigerate at 2–8°C, use within 30 days. Avoid repeated freeze-thaw cycles.
Chemical Makeup
Key benefits
Increases GH secretion by up to 97% and sustains elevated IGF-1 levels, supporting lean muscle accrual without changes in total fat mass
Improves slow-wave (stage IV) sleep by approximately 50% and REM sleep by over 20%, enhancing overnight recovery and tissue repair
Increases bone mineral density over long-term use, with clinical evidence of benefit in obese individuals, older adults, and postmenopausal women
Preserves and increases lean body mass in catabolic states such as aging-related GH decline and caloric restriction
Community interest
This peptide is still gaining traction in the community.
GHS-R1a Agonist | Lean Mass & Bone Density Research
This overview is informational and based on aggregated descriptions from studies and user reports.
Was it helpful?YesNoMK-677 Molecular Information
View the scientifc details of MK-677.
2
Amino Acids
MK-677
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?
Position 1
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Position 2
Molecular Weight
528.67DaChain Length
2Amino AcidsType
PeptideMK-677 Protocols
Oral administration is the primary and clinically studied route for MK-677 (Ibutamoren), a non-peptide small molecule GH secretagogue with greater than 60% oral bioavailability. Dosing before bed on an empty stomach aligns with the body's natural nocturnal GH pulse and minimizes daytime hunger side effects.
| Goal | Dosage | Frequency | Route |
|---|---|---|---|
| Sleep enhancement and recovery | 10 | 1 day range | Oral (before bed, empty stomach) |
| Balanced GH elevation and body composition | 15 | 1 day range | Oral (before bed, empty stomach) |
| Muscle growth and body composition | 25 | 1 day range | Oral (before bed, empty stomach) |
| Anti-aging and IGF-1 optimization | 15 | 1 day range | Oral (before bed, empty stomach) |
| Bone density improvement | 25 | 1 day range | Oral (before bed, empty stomach) |
| Maximum GH secretion (high-dose research) | 50 | 1 day range | Oral (before bed, empty stomach) |
Reconstitution Instructions
Materials needed:
Steps to reconstitute
- If using capsules: remove one pre-measured capsule (10 mg or 25 mg) from the bottle — do not open or crush the capsule
- Swallow the capsule whole with a full glass of water (8 oz / 240 mL)
- If using liquid solution (typically 25 mg/mL in PEG-400 or ethanol carrier): shake the bottle well before measuring
- Draw the required volume into the provided dropper or oral syringe — for example, 1.0 mL delivers 25 mg from a 25 mg/mL solution
- Dispense the liquid directly into the mouth and swallow; chase with water to clear any carrier taste
- Take at least 2 hours after your last meal for optimal GH response — bedtime on an empty stomach is preferred
- Dose at the same time each day to maintain stable trough levels given MK-677's 24-hour half-life
- Store capsules at room temperature away from heat and moisture; refrigerate liquid solution after opening if instructed by the supplier
MK-677 Cycle
The MK-677 Cycle section explains how long a typical cycle lasts and what to expect during each phase. Over time, your body can become less responsive with continuous use.
Taking breaks between cycles may help maintain effectiveness and support better overall results.
- Week 1-2
- Improved sleep quality, vivid dreams, possible appetite increase
- Week 2-4
- Enhanced recovery, better sleep architecture, initial body composition changes
- Week 4-8
- Noticeable lean mass gains, continued sleep benefits
- Week 8-12
- Maximum body composition improvements, sustained GH elevation
Dosing tools
MK-677 Peptide Dosage Calculator
Calculate peptide doses with our visual syringe guide.
mg
Enter the total amount of peptide in the vial in milligrams (as stated on the label).
The dose you want to inject per administration, in mcg or mg.
1,000 mcg = 1 mg
1 mL
2 mL
3 mL
5 mL
Custom
Volume of bacteriostatic water you add to reconstitute the powder. Use BAC water for preservation.
Injection Results
Based on your vial and dilution inputs.
MK-677
SINGLE COMPOUNDVolume per injection
0.05
mL
Concentration
10.00
mg/mL
Doses per vial
20
doses
Total injections per vial
20 injections
How it works
Based on a 10 mg MK-677 vial diluted with 1 mL of bacteriostatic water, each 500 mcg injection equals 0.05 mL.
1mL / 100 units
5 units
0.050 mL
Reference Guide
Dosing Cycle
- Peptide
- MK-677
- Dosing
- 10–25mg per day orally
- Dosing Frequency
- once daily, preferably at night
- Cycle Duration
- 12–16 weeks on, 4–8 weeks off
- Storage
- Powder/capsule: room temperature, cool dry place away from light and moisture. Liquid/reconstituted: refrigerate at 2–8°C, use within 30 days. Avoid repeated freeze-thaw cycles.
Note: Triple agonist; microdose for fewer side effects
Reconstitution Tips
- Use bacteriostatic water (BAC) — contains 0.9% benzyl alcohol for preservation
- Inject water slowly — aim down the vial wall, not directly onto powder
- Never shake — gently swirl or roll the vial until dissolved
- Store properly — refrigerate at 2-8°C after reconstitution
- Use within 28 days — most reconstituted peptides remain stable for about 4 weeks
- Keep sterile — always clean vial tops with alcohol before drawing
Peptide Interactions
Research suggestions of MK-677 interactions with other common peptides and substances.
Weight
ghr
Growth
GHRP-2
SYNERGISTIC
MK-677 baseline elevation combines with GHRP-2 pulsatile spikes.
Weight
ipa
Growth
Ipamorelin
SYNERGISTIC
Both stimulate GH release through different mechanisms.
Side effects
Avoid: Do not take MK-677 with HGH.
Contraindications
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
Stop signs
Shortness of breath, chest pain, or unusual fatigue
Blood glucose levels >100mg/dL or diabetes symptoms
Liver enzyme elevation (ALT/AST >2x upper normal)
Severe fluid retention or unexplained swelling
Any concerning cardiovascular symptoms
Bad signs
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Frequently asked questions
What is a peptide dosage calculator?
A peptide dosage calculator is a free tool that converts your vial size, bacteriostatic water volume, and target dose into an exact syringe draw volume. Instead of doing the reconstitution math by hand, you enter three inputs and instantly get the concentration of your solution and how many milliliters or syringeunits to draw. This calculator works for single peptide compounds and multi-peptide blends.
How do I calculate peptide dosage from a vial?
To calculate your peptide dose, divide the total peptide content of your vial in micrograms by the volume of bacteriostatic water you added in milliliters. This gives you your solution concentration in mcg/mL. Then divide your target dose by that concentration to get your draw volume. For example, a 5mg (5,000 mcg) vial reconstituted with 2mL of BAC water gives a concentration of 2,500 mcg/mL. A 250 mcg dose would require drawing 0.1mL. This calculator automates all of those steps instantly.
How much Bacteriostatic water should I add to a peptide vial?
Most people add 2mL to 3mL of bacteriostatic water per vial, but the right amount depends on the dose you want to draw and the syringe size you are using. Adding 1mL to a 5mg vial gives you a concentration of 5,000 mcg/mL, making each dose very small in volume. Adding 2mL gives you 2,500 mcg/mL, which is easier to measure on a standard insulin syringe. A general guideline is to choose a volume that puts your typical dose somewhere between 10 and 30 units on a U-100 syringe. Use the calculator above to test different water volumes and find what works for your dose.
How are peptides different from proteins?
Both are made of amino acids, but peptides are much smaller than proteins. Because of their tiny size, peptides can act like tiny messengers in the body, sending specific signals to your cells to tell them exactly what to do.
MK-677Research References
MK-677 is a phase 2 compound
MK-677
MK-677 is a phase 2 compound
Sleep Quality Improvement Study
25mg oral daily for 1 week showed 20% REM increase in young adults; 50% in elderly.
1997
Growth Hormone Stimulation in Elderly
25mg oral daily for 2 weeks showed 97% increase in 24-hour GH secretion in elderly adults.
1996
Body Composition in Obese Subjects
25mg oral daily for 2 months increased fat-free mass and energy expenditure in obese adults.
1998
Reversal of Diet-Induced Catabolism
25mg oral daily for 7 days showed nitrogen retention of +2.69g/day versus placebo -8.97g/day.
1998
Bone Turnover Markers Study
25mg oral daily for 2 months showed 39-45% increase in bone formation markers in elderly adults.
1999
Calculate peptide dosages
Learning how to calculate a peptide dose? Use our beginner-friendly peptide dosage, blend, and accumulation calculators. Enter vial size, reconstitution volume, and target dose to get exact draw volumes instantly. No guesswork, just clear guidance that helps prevent common mistakes.
