Skip to content
The Peptide Effect
Dosage Guide

MK-677 (Ibutamoren) Dosage Guide: Oral Protocol

Educational reference for MK-677 (ibutamoren) oral dosage protocols discussed in research literature. Covers conservative, standard, and advanced dosing approaches for this oral growth hormone secretagogue.

View MK-677 profile →

Medical Disclaimer

This guide is for educational and informational purposes only. It is not medical advice. Dosages described reflect ranges discussed in published research and clinical practice literature — they are not recommendations. Always consult a licensed healthcare provider before using any peptide. Legality and availability vary by jurisdiction.

Overview

MK-677 (ibutamoren mesylate) is a non-peptide, orally active growth hormone secretagogue that mimics the action of ghrelin at the growth hormone secretagogue receptor (GHS-R1a). Unlike injectable peptides such as CJC-1295 or ipamorelin, MK-677 is taken orally as a pill or capsule, making it one of the most accessible compounds in the GH-axis category. Research by Murphy et al. (1998) demonstrated that MK-677 significantly increased GH and IGF-1 levels in healthy older adults without serious adverse effects over 2 weeks of daily dosing. A subsequent 2-year study by Nass et al. (2008) showed that MK-677 sustained elevated GH and IGF-1 levels in healthy elderly subjects, restoring them to levels seen in younger adults. MK-677 does not suppress the body's natural GH production — it amplifies endogenous secretion through the ghrelin pathway, preserving the pulsatile pattern of GH release.

Dosing Protocols

Conservative Start Protocol

Route: Oral
Dose: 10 mg
Frequency: Once daily
Duration: 2–4 weeks (before escalating)

A lower starting dose discussed in research literature to assess individual tolerance. Helps gauge appetite stimulation and water retention before increasing. Can remain at this dose if side effects are a concern. Taken with or without food, though some protocols describe evening dosing to take advantage of enhanced sleep quality.

Standard Protocol

Route: Oral
Dose: 10–25 mg
Frequency: Once daily
Duration: 8–16 weeks (up to 6–12 months in some research)

The most commonly referenced dosage range in clinical studies. The original Murphy et al. trial used 25 mg daily. The 2-year Nass et al. study also used 25 mg daily. Many research community discussions describe 15–20 mg as a balance between efficacy and side effect management. Once-daily dosing is sufficient due to MK-677's long half-life (~24 hours).

Advanced Protocol

Route: Oral
Dose: 25 mg
Frequency: Once daily
Duration: 12–24 weeks

The dose used in most published clinical trials. Research by Nass et al. (2008) administered 25 mg daily for up to 2 years. At this dose, increased appetite and water retention are more pronounced. Some protocols describe splitting the dose (12.5 mg AM, 12.5 mg PM) to manage appetite stimulation, though this is not supported by clinical data. For educational reference only.

Cycle Guidance

MK-677 has been studied in trials lasting up to 2 years of continuous daily administration (Nass et al. 2008), making it one of the longest-studied compounds in this category. Research literature discusses both cycled and continuous approaches. Cycled protocols typically describe 8–16 weeks on followed by 4–8 weeks off to manage side effects such as appetite stimulation and insulin sensitivity changes. Continuous low-dose protocols (10–15 mg) are also discussed for longer durations. Blood glucose monitoring is advisable during extended use, as MK-677 can affect insulin sensitivity over time.

Stacking Considerations

  • MK-677 is an oral GH secretagogue, so it is sometimes discussed as redundant with injectable GHRH/GHRP combinations (CJC-1295 + Ipamorelin) — using both simultaneously targets the GH axis through overlapping mechanisms.
  • Some research protocols describe MK-677 as a convenient oral alternative to injectable GH-axis peptides for those who prefer not to inject.
  • Discussed alongside cardarine (GW-501516) in some research contexts for combined body composition effects, though GW-501516 carries its own safety concerns.
  • May be combined with AOD-9604 — since AOD-9604 targets lipolysis without affecting GH/IGF-1, the mechanisms are complementary rather than redundant.
  • Testosterone or other anabolic compounds are sometimes discussed alongside MK-677 in bodybuilding research contexts, though this significantly increases complexity and risk.

Potential Side Effects

  • Increased appetite — this is the most commonly reported effect, driven by MK-677's ghrelin-mimetic action; can be significant at 25 mg
  • Water retention and bloating — particularly in the first 2–4 weeks; usually diminishes with continued use
  • Lethargy and fatigue — reported during initial use, particularly with evening dosing
  • Numbness or tingling in extremities — associated with elevated GH levels; usually transient
  • Mild muscle or joint pain — consistent with GH-related fluid shifts
  • Elevated fasting blood glucose — reported in the 2-year Nass et al. study; insulin sensitivity may decrease with prolonged use
  • Vivid dreams — commonly reported, possibly related to enhanced deep sleep stages
  • Increased cortisol upon waking — reported in some studies, though generally within normal ranges

Contraindications & Cautions

  • Type 2 diabetes or insulin resistance — MK-677 can worsen glycemic control and reduce insulin sensitivity
  • Active malignancy — elevated GH and IGF-1 may promote tumor growth
  • Congestive heart failure — GH elevation can worsen fluid retention and cardiac load
  • Pregnancy or breastfeeding — no safety data in these populations
  • Pituitary tumors — stimulation of the GH axis may be contraindicated
  • Individuals with a history of or predisposition to carpal tunnel syndrome

Related

MK-677 Profilemuscle growthsleepanti agingrecoveryfat lossipamorelin dosagecjc-1295 dosagesermorelin dosage

References

  1. MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism (1998) — PubMed
  2. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial (2008) — PubMed
  3. Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure (1997) — PubMed
  4. Oral administration of growth hormone (GH) releasing peptide-mimetic MK-677 stimulates the GH/IGF-I axis in selected GH-deficient adults (2001) — PubMed

Frequently Asked Questions

Is MK-677 a peptide or a SARM?
MK-677 is neither a peptide nor a SARM (selective androgen receptor modulator), though it is frequently miscategorized as both. It is a non-peptide growth hormone secretagogue — a small molecule that mimics the hormone ghrelin and binds to the ghrelin receptor (GHS-R1a) to stimulate growth hormone release from the pituitary. It is orally bioavailable, unlike most peptides which require injection. It does not interact with androgen receptors.
Should MK-677 be taken in the morning or at night?
Both timings are discussed in research literature. Evening or bedtime dosing is commonly preferred because MK-677 enhances deep sleep quality and synergizes with the natural nocturnal GH pulse. However, the increased appetite effect can be more manageable with morning dosing. Due to MK-677's long half-life of approximately 24 hours, the specific timing may be less critical than consistent daily administration. Some users report excessive sleepiness with daytime dosing.
Does MK-677 affect testosterone or require PCT?
MK-677 does not directly affect testosterone production, the hypothalamic-pituitary-gonadal (HPG) axis, or androgen receptors. It does not cause testosterone suppression and does not require post-cycle therapy (PCT). Its mechanism is limited to the GH axis via ghrelin receptor stimulation. This is a key distinction from SARMs and anabolic compounds, which do affect the HPG axis.
Can MK-677 cause diabetes?
MK-677 can impair insulin sensitivity and elevate fasting blood glucose, particularly with prolonged use. The 2-year Nass et al. study reported increased fasting glucose levels in the MK-677 group. However, this does not mean MK-677 directly causes diabetes. Individuals with pre-existing insulin resistance, metabolic syndrome, or a family history of type 2 diabetes should exercise particular caution. Monitoring fasting glucose and HbA1c during extended use is advisable.
How long does MK-677 take to work?
GH and IGF-1 levels begin to rise within the first few days of administration. Improved sleep quality and vivid dreams are commonly reported within the first week. Appetite stimulation typically begins within 1–3 days. Visible changes in body composition (increased fullness, water retention initially, then lean mass gains over time) are generally discussed at the 4–8 week mark with continued effects building over 3–6 months of consistent use.
Does MK-677 need to be cycled?
Cycling is debated. The longest published clinical trial (Nass et al. 2008) administered MK-677 continuously for 2 years without apparent loss of efficacy for GH/IGF-1 elevation. However, the metabolic effects (particularly on insulin sensitivity) worsened over time, providing a practical argument for cycling. Common cycling protocols discussed in research contexts include 8–16 weeks on, 4–8 weeks off. Continuous low-dose approaches (10 mg daily) are also discussed as an alternative to cycling.