Peptide Schedule

MK-677 (Ibutamoren)

Growth HormoneOralResearchGrade C~5 hours (IGF-1 elevation lasts ~24h) half-life
Growth HormoneOralSleepBone DensityBody Composition

Benefits

Oral dosing — no injections needed
Sustained 24-hour GH and IGF-1 elevation
Raises IGF-1 by 40-60% within weeks
Improves sleep quality (deep sleep)
Does not suppress natural GH axis
Half-Life
~5 hours
Route
Oral
Frequency
Daily
Vial Sizes
25mg
BAC Water
Pre-filled
Safety Grade
Grade C
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About MK-677 (Ibutamoren)

MK-677 (Ibutamoren) is an orally active, non-peptide growth hormone secretagogue that mimics ghrelin signaling. Unlike injectable GH peptides, it's taken by mouth and produces sustained 24-hour elevation of GH and IGF-1 levels. A single daily dose raises IGF-1 by 40-60% within weeks. It does not suppress natural GH production and can be used long-term, though it increases appetite and may affect insulin sensitivity.

Who Should Consider MK-677 (Ibutamoren)

  • Older adults with age-related GH decline seeking improved body composition
  • Individuals wanting GH benefits without injections (oral dosing)
  • People with poor sleep quality seeking deeper sleep stages
  • Post-menopausal women at risk of osteoporosis (adjunctive use)
  • Athletes and bodybuilders seeking recovery and lean mass gains

What to Expect

Days 1-7

Appetite increases noticeably within the first few days. Mild water retention and improved sleep quality often reported by end of week one.

Weeks 2-4

IGF-1 levels rise 40-60% above baseline. Sleep deepens with increased stage IV and REM duration. Vivid dreams are common.

Weeks 4-8

Bone turnover markers increase — osteocalcin rises ~29%. Skin and hair quality begin improving. Strength and recovery show early gains.

Months 2-6

Measurable increases in fat-free mass (~1.1 kg over 12 months in clinical data). Body recomposition becomes visible. Bone mineral density trends upward.

Months 6-12

Sustained IGF-1 elevation and body composition changes. Monitor fasting glucose closely as insulin sensitivity may decline with prolonged use.

Dosing Protocol

LevelDose / InjectionFrequency
Beginner10mgDaily
Moderate15mgDaily
Aggressive25mgDaily

Note: Oral GH secretagogue — not a peptide, but a non-peptide ghrelin mimetic. Often available as capsules or liquid. No injection required. Take at bedtime to minimize hunger side effect. Monitor fasting blood sugar.

Pharmacokinetics

Half-Life
5h
Bioavailability
Oral: >60%
Tmax
1-2 hours oral
Data Confidence
moderate

Source: Plasma elimination t½ of 4-6 hours in preclinical models; GH/IGF-1 pharmacodynamic effects persist ~24 hours allowing once-daily dosing

Pharmacokinetics — Active Dose Over Time

t½ = ~5 hours (IGF-1 elevation lasts ~24h)
50%25%12.5%100%75%50%25%0%05h10h15h20h25hTime after injectionDose remaining
After 1 half-life (5h): 50% remainsAfter 2 half-lives (10h): 25% remainsAfter 3 half-lives (15h): 12.5% remains
At a 15mcg dose: 50% = 8mcg remaining after 5h. Recommended frequency: Daily.

Disclaimer: This curve is a simplified first-order exponential decay model. Actual pharmacokinetics vary based on injection site, individual metabolism, body composition, and other factors. Half-life values are approximate and based on available preclinical and clinical literature. Many research peptides lack formal human pharmacokinetic studies. This is for educational purposes only — not medical advice.

Side Effects

Increased appetite and water retention. May elevate fasting blood sugar and reduce insulin sensitivity with prolonged use. Lethargy, vivid dreams. Monitor glucose regularly.

Contraindications

  • Active malignancy — sustained GH and IGF-1 elevation may promote tumor growth
  • Type 2 diabetes or significant insulin resistance — MK-677 worsens glycemic control
  • Prediabetes with fasting glucose above 110 mg/dL without close monitoring
  • Congestive heart failure or conditions worsened by fluid retention
  • Untreated or severe obstructive sleep apnea
  • Pregnancy or breastfeeding — no human safety data available
  • Known hypersensitivity to ibutamoren or its excipients

Drug Interactions

  • Insulin, metformin, and sulfonylureas — MK-677 promotes insulin resistance; antidiabetic doses may need adjustment
  • Corticosteroids — additive fluid retention and edema risk; may also blunt GH-mediated effects
  • CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir) — may increase MK-677 plasma levels due to hepatic CYP450 metabolism
  • Thyroid hormones — GH elevation can unmask central hypothyroidism; monitor TSH and free T4
  • Anticoagulants (warfarin) — GH pathway alterations may affect hepatic synthesis of clotting factors; monitor INR

Molecular Profile

Molecular Weight
528.67 Da
Formula
C27H36N4O5S
Type
Small Molecule

Related Peptides

HGH 191AA
Growth Hormone
Ipamorelin
Growth Hormone
CJC-1295 + Ipamorelin
Growth Hormone

References

  1. MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism (Murphy et al., JCEM 1998)PubMed 9467534
  2. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults (Nass et al., Ann Intern Med 2008)PubMed 18981485
  3. Prolonged oral treatment with MK-677 improves sleep quality in man (Copinschi et al., Neuroendocrinology 1997)PubMed 9349662
  4. Treatment with the oral GH secretagogue MK-677 increases markers of bone formation and resorption in obese young males (Svensson et al., JCEM 1998)PubMed 9661080
  5. Stimulation of the GH-IGF-I axis by daily oral administration of a GH secretagogue MK-677 in healthy elderly subjects (Chapman et al., JCEM 1996)PubMed 8954023

Frequently Asked Questions