Reviewed by the PeptideMind Team · Updated August 5, 2026

MK-677 (Ibutamoren) Dosage Guide, Benefits & Side Effects

MK-677 (Ibutamoren) raises GH and IGF-1 around the clock to support lean muscle, deep sleep, and recovery. See dosing guidelines, benefits, and side effects.

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What is MK-677?

MK-677 (Ibutamoren) is a lab-made compound (not a true peptide) that you take as a pill rather than an injection, and it works by mimicking the 'hunger hormone' ghrelin to trigger a steady release of growth hormone and a related growth factor (IGF-1). It has been tested in human trials for muscle mass, bone strength, and growth hormone support in older adults. It's studied for its ability to build lean muscle and support bone density without shutting down the body's own natural hormone production.

Weight

Research targets include appetite regulation, fat metabolism, and body composition.

Growth

Research targets include growth hormone signaling, IGF-1 pathways, and tissue development.

Sleep

Research targets include circadian rhythm regulation and sleep quality pathways.

Growth

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What Does MK-677 Do?

It mimics the 'hunger hormone' ghrelin at its receptor in the brain, triggering a pulsing release of growth hormone and the related growth factor IGF-1. It does this without shutting down the body's own natural hormone feedback loops, the way giving growth hormone directly can.

Mimics ghrelin

Mimics the 'hunger hormone' at its brain receptor.

Pulses GH & IGF-1

Triggers a pulsing release of growth hormone and the related growth factor IGF-1.

Preserves feedback loops

Doesn't shut down the body's own natural hormone feedback, unlike direct GH.

Frequently Asked Questions About MK-677

Straight answers on reconstitution, dosing, and safety, everything you need to research with confidence. For research reference only.

MK-677 (ibutamoren) is technically not a peptide but a small-molecule, orally active ghrelin mimetic and growth hormone secretagogue. It binds the ghrelin receptor in the pituitary and hypothalamus, stimulating the release of growth hormone (GH) and, downstream, IGF-1. Unlike injectable GH-releasing peptides (e.g., CJC-1295, ipamorelin), it is taken orally and produces a more sustained, all-day elevation in GH/IGF-1 rather than a single sharp pulse.

Most research and anecdotal protocols use 10-25 mg once daily, commonly taken at night on an empty stomach (its long half-life, roughly 24 hours, allows once-daily dosing). Clinical trials studying muscle and bone effects in older adults generally used 25 mg/day. There is no medically established 'safe' human dose since MK-677 is not an approved drug; any dosing information reflects research protocols and community reports, not medical guidance.

The most frequently reported effects include increased appetite (often significant), water retention/mild edema, lethargy or grogginess, joint stiffness or aches, and transient numbness/tingling in the extremities. Because MK-677 raises GH and IGF-1, it can also reduce insulin sensitivity and raise fasting blood glucose and HbA1c with continued use, an effect seen across multiple clinical trials. Effects tend to be dose-dependent, with higher doses associated with more pronounced water retention and blood sugar changes.

Users and available research commonly describe improved sleep quality, appetite, and recovery within 2-4 weeks, with changes in body composition (lean mass, fat loss) more often reported after 6-8+ weeks of consistent use. Because animal data suggest the body can upregulate somatostatin (a natural brake on GH release) with prolonged continuous use, many protocols cycle MK-677 in blocks of roughly 8-12 weeks followed by a break of several weeks, though there is no standardized clinical cycling protocol.

Yes, this is one of the most common questions and combinations discussed in peptide communities. The rationale given is that injectable GHRH/GHRP peptides (CJC-1295, ipamorelin) produce a sharp, pulsatile GH release while MK-677 provides a longer, steadier elevation, so combining them is claimed to broaden the GH/IGF-1 response across the day. This combination is not studied in controlled human trials, so claims about added benefit are based on mechanism and anecdotal reports rather than clinical evidence.

MK-677 has never been approved by the FDA (or equivalent regulators elsewhere) for any human use. It is not a scheduled/controlled substance in the US, so simple possession is generally not a criminal matter, but it is sold only as a 'research use only' chemical not intended for human consumption, and marketing it for human/bodybuilding use has drawn FDA warning letters to sellers. It is also on WADA's prohibited list (category S2) for tested athletes and is flagged on the DoD's high-risk supplement list, so competitive athletes and military personnel should assume it is banned for them.

Because MK-677 is a small molecule rather than a reconstituted peptide, it is generally more stable than injectable peptides and does not require refrigeration or reconstitution. Vendors typically supply it as a stable powder or pre-dosed liquid/capsule; common guidance is to store it in a cool, dry place away from direct light and moisture, and to follow the specific supplier's stated stability and expiration information, since formulations vary.

This is a frequently raised concern because ghrelin-receptor activity and increased GH/IGF-1 can theoretically influence DHT sensitivity, and some users report increased shedding, though there is no strong clinical evidence establishing MK-677 as a direct cause of hair loss. Some studies and user reports note mild increases in cortisol and prolactin with GH secretagogue use; the clinical significance of these changes in healthy adults is not well established. As with other effects, findings are drawn from limited trials and self-reported experience rather than robust human safety data.

MK-677 Reconstitution Guide

MK-677 is supplied as a freeze-dried powder that must be mixed into a injectable solution before use. Available in 10mg, 25mg sizes.

25 mg (capsule or liquid) lyophilized vial

MK-677 is supplied as a freeze-dried powder that must be mixed into a injectable solution before use. Available in 10mg, 25mg sizes.

NaN mL bacteriostatic water

Adding NaN mL of bac water to a 25 mg (capsule or liquid) vial gives a workable concentration for syringe dosing. More water makes microdosing easier; less concentrates each draw.

Storage after mixing

The powder or capsule form can sit at room temperature in a cool, dry, dark place. Once mixed into liquid, refrigerate and use within a month, avoiding repeated freezing and thawing. After reconstitution, keep the vial refrigerated and use within 30 days.

Reconstitution steps

Remove caps & sanitize stoppers

Attach needle to syringe

Draw NaN mL bacteriostatic water

Insert needle into MK-677 vial

Release water gently down the side

Swirl to dissolve — don't shake

Check for full dissolution

Refrigerate MK-677 — good for 30 days

Chemical Makeup

Amino Acids

MK-677

Position 1

Position 2

Amino acid sequence

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What Are the Benefits of MK-677?

What research says it may help with, and how it works in the body.

growth hormone

: Raised growth hormone output in older adults back toward more youthful levels, increasing 24-hour secretion by 97% in studies.
: Keeps IGF-1, a growth-related hormone, elevated by 40 to 72% over long periods of use.
: Increased REM (dream-stage) sleep by 20% in younger adults and by 50% in older adults in studies.

body composition

: Increases fat-free body mass, with the gains favoring lean tissue like muscle.
: Raised resting calorie burn (metabolic rate) by 15% within two weeks in studies.
: Helped the body hold onto more protein (measured as nitrogen retention) during dieting, gaining about 2.69g per day compared to losing 8.97g per day with placebo, which helps protect muscle mass while cutting calories.

bone health

: Increased markers of new bone formation by 39 to 45% within 6 to 8 weeks.

What Are the Side Effects of MK-677?

Who should avoid it, warning signs to watch for, and what to know before combining it with other compounds.

Who Should Avoid It

: Heart disease or congestive heart failure
: Diabetes or pre-diabetes
: Active cancer
: Severe cardiovascular disease
: Pregnancy or breastfeeding

Stop Right Away If You Notice

: 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

Milder Signs to Watch For

Dietary supplement claims (FDA prohibits MK-677 in supplements)Unknown purity or source without certificates of analysisUnusually low prices suggesting counterfeit product

Was it helpful?Yes

Is MK-677 FDA approved?

MK-677 is not an FDA-approved drug. It is intended for research purposes only and is not approved for human consumption, diagnostic, or therapeutic use.

Research Use Only

MK-677 has not been evaluated by the FDA for safety or efficacy in humans.

No Clinical Oversight

Not manufactured under FDA-regulated quality or clinical standards.

Unregulated Sourcing

Purity, dosing, and sourcing are not verified through FDA testing or oversight.

A smartphone screen displaying FDA status for a drug, indicating "FDA approved drug: No" and "Classification: Research use only." A banner notes "Research Only" with the disclaimer "not for human use," emphasizing its intended use for laboratory and analytical purposes.

MK-677 Cycle Length: How Long Should It Last?

This breaks down how long a typical MK-677 cycle runs and what research suggests happens at each stage. Research shows that staying on a peptide continuously, without a break, may make it less effective over time.

That's why most research protocols build in a break between cycles, often called a washout period, to let the body reset before starting again.

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

MK-677 Research References

It is a phase 2 compound

5Research references

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

Reversal of Diet-Induced Catabolism

25mg oral daily for 7 days showed nitrogen retention of +2.69g/day versus placebo -8.97g/day.

1998

Body Composition in Obese Subjects

25mg oral daily for 2 months increased fat-free mass and energy expenditure in obese adults.

1998

Bone Turnover Markers Study

25mg oral daily for 2 months showed 39-45% increase in bone formation markers in elderly adults.

1999

Browse user-created protocols

Real protocols from the community that include MK-677

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MK-677 (Ibutamoren) Dosage Guide, Benefits & Side Effects