MK-677 Dosing: Protocols & Timing (2026)

MK-677 (ibutamoren) is a non-peptide growth hormone secretagogue that mimics ghrelin to stimulate natural GH release. Unlike true peptides, it's orally bioavailable and doesn't require injection, making it one of the most accessible compounds in the growth hormone space.

Clinical trials exist with human data spanning up to 2 years of continuous use. This puts MK-677 in a unique position compared to most research peptides.

This is not medical advice. MK-677 is not FDA-approved for any indication and is sold as a research chemical.

Quick Reference: Community Dosing

Most people start at 10mg daily and increase to 25mg based on appetite and water retention tolerance. Taken 30-60 minutes before bed for optimal timing with natural GH pulses.

For the full MK-677 profile, vendor pricing, and stack protocols, see our MK-677 peptide page.

Loading vs Maintenance

Unlike injectable peptides, MK-677 doesn't follow a traditional loading/maintenance pattern due to its long half-life (~24 hours):

Week 1-2: Start at 10mg daily to assess tolerance. Common side effects (appetite, water retention) are most pronounced in the first 1-2 weeks.

Week 3+: Increase to 15-25mg daily based on response and tolerance. Most users settle at 20-25mg for optimal GH stimulation without excessive side effects.

Typical Protocol Lengths

• Beginners: 8 weeks on, 4 weeks off
• Experienced users: 12 weeks on, 4-8 weeks off
• Long-term use: Some run 6+ months continuously (based on clinical studies)
• Competition prep: 16-20 weeks leading up to competition

Routes of Administration

Oral (Only Route)

MK-677 is orally bioavailable — one of its key advantages over injectable peptides.

Liquid solutions are most common, typically dosed with a 1mL dropper. Taste ranges from neutral to slightly bitter depending on the carrier solution.

Capsules are available but less common. Standardized dosing but slower absorption compared to liquid.

Timing considerations:

• Before bed — aligns with natural GH pulses and mitigates daytime appetite increase
• Empty stomach — may improve absorption but not strictly necessary
• Post-workout — some users prefer this timing for anabolic effects, though night dosing is more common

Sublingual Absorption

Some liquid formulations are designed for sublingual (under tongue) administration for faster absorption, though oral swallowing is equally effective given MK-677's oral bioavailability.

Where These Numbers Come From: Clinical Context

Unlike most research peptides, MK-677 has substantial human clinical data that directly informs community dosing.

Clinical Study Doses

Murphy et al. (1998) — 25mg daily reversed diet-induced catabolism and significantly increased GH and IGF-1 levels in healthy volunteers (PMID 9467534).

Nass et al. (2008) — 2-year study using 25mg daily showed sustained increases in GH, IGF-1, and lean body mass with acceptable safety profile (PMID 18981485).

Why Community Doses Match Clinical Doses

This is rare in the peptide world — the community 10-25mg range directly mirrors clinical trial dosing:

• 25mg daily was the standard dose in most efficacy studies
• 10mg daily showed activity but with diminished returns
• Higher doses (50mg+) showed no additional benefit but increased side effects
• No scaling required — human clinical data eliminates the need for animal-to-human dose conversion

Oral Bioavailability

MK-677 has excellent oral bioavailability (~60-70%), which is why oral dosing works. Most peptides are destroyed in stomach acid, but MK-677's non-peptide structure remains stable through digestion.

Mechanism of Action

MK-677 works by binding to and activating the ghrelin receptor (GHS-R1a) in the pituitary gland:

Ghrelin receptor activation — MK-677 mimics ghrelin, the "hunger hormone," binding to the same receptors that control GH release. This triggers a cascade leading to growth hormone secretion (Nass et al., 2008).

Pulsatile GH release — Unlike exogenous GH, MK-677 stimulates natural pulsatile release patterns, preserving the body's normal GH rhythm while increasing amplitude (Murphy et al., 1998).

IGF-1 elevation — Sustained increases in IGF-1 (the primary mediator of GH's anabolic effects) occur within days of starting treatment and persist throughout use (Copinschi et al., 1997).

No negative feedback — Unlike exogenous GH, MK-677 doesn't suppress natural GH production through negative feedback loops, making it safer for long-term use.

Side Effects & Safety

MK-677 has a well-documented side effect profile from clinical trials:

Common Side Effects (Clinical Studies)

• Increased appetite — occurs in 80%+ of users, usually within the first week
• Water retention/edema — mild to moderate, typically subsides after 2-4 weeks
• Mild insulin resistance — temporary and reversible upon discontinuation
• Lethargy/fatigue — especially during the first 2-3 weeks
• Joint stiffness — from water retention, usually mild

Less Common Side Effects

• Elevated prolactin — in some individuals, typically not clinically significant
• Carpal tunnel symptoms — from water retention, rare
• Headaches — usually in the first week

Long-term Safety

The 2-year Nass study provides the best long-term safety data:

• No significant changes in prostate health, cardiovascular markers, or cancer incidence
• Reversible mild insulin resistance
• No long-term negative effects on natural GH production
• Safe discontinuation with return to baseline within 2-4 weeks

Managing Side Effects

• Start at 10mg — assess tolerance before increasing dose
• Take before bed — reduces daytime appetite and water retention impact
• Manage carbohydrates — helps with insulin sensitivity
• Stay hydrated — helps with water retention and headaches

Stacking MK-677

MK-677 works through ghrelin receptors, making it complementary to other GH-related compounds:

MK-677 + Ipamorelin (Popular Stack)

Ipamorelin works through GHRH receptors while MK-677 works through ghrelin receptors — different pathways, synergistic effects:

MK-677 + CJC-1295

Long-acting GHRH (CJC-1295) pairs well with the continuous ghrelin stimulation from MK-677:

MK-677 + GHRP-2/GHRP-6

Classic combination — oral convenience of MK-677 with injectable potency of GHRPs:

• MK-677 provides baseline GH elevation
• GHRP-2/6 adds acute post-workout spikes
• Timing: MK-677 at bedtime, GHRPs post-workout

Stacking Tips

• MK-677's oral route makes it the easiest addition to any peptide stack
• No injection site competition with other peptides
• Can run longer cycles than most injectable peptides
• Monitor blood sugar more closely when stacking multiple GH compounds

Frequently Asked Questions

What is the standard MK-677 dose?

The most common community protocol is 10-25mg taken orally before bed, daily for 8-12 weeks followed by 4 weeks off. This directly aligns with clinical studies that used 25mg daily and showed significant increases in GH and IGF-1.

Is MK-677 actually a peptide?

No — MK-677 (ibutamoren) is a non-peptide growth hormone secretagogue. Unlike true peptides, it's orally bioavailable and doesn't require injection. It mimics ghrelin to stimulate natural GH release from the pituitary.

Why is MK-677 taken at night?

Natural GH release peaks during deep sleep stages. Taking MK-677 before bed aligns with this natural circadian rhythm and may enhance sleep quality. It also helps mitigate daytime appetite stimulation.

How long should an MK-677 cycle last?

Common protocols are 8-12 weeks on, 4 weeks off. The 2-year Nass study showed sustained effects without major issues, but cycling is recommended to prevent receptor desensitization and allow natural patterns to reset.

What are MK-677's main side effects?

The most common side effects are increased appetite (80%+ of users), water retention, mild insulin resistance, and initial lethargy. These are generally dose-dependent and often subside after 2-3 weeks of use.

Can I take MK-677 with other peptides?

Yes — MK-677 stacks excellently with other GH-related peptides like ipamorelin, CJC-1295, or GHRPs. Since it works via ghrelin receptors while others work via GHRH pathways, the mechanisms are complementary.

Does MK-677 need to be cycled?

While the 2-year clinical study showed continuous use was tolerable, cycling 8-12 weeks on/4 weeks off is recommended to prevent receptor desensitization and maintain effectiveness.

Will MK-677 show up on drug tests?

MK-677 is prohibited by WADA and may be tested for in athletic competitions. It's not included in standard employment drug screens but can be detected with specialized testing.

Related Guides

• MK-677 Peptide Page — Vendor pricing, stack protocols, and full compound profile
• Ipamorelin Dosing Guide — Injectable alternative to MK-677
• CJC-1295 + Ipamorelin Stack Guide — Stacking MK-677 with GHRH/GHRP
• GHRP-2 Dosing Guide — Another injectable growth hormone peptide

References

For educational and research purposes only. This is not medical advice. MK-677 is not FDA-approved for any indication and is sold as a research chemical.