MK-677 (Ibutamoren)
Other ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
MK-677, or ibutamoren, is an orally active non-peptide ghrelin receptor agonist commonly grouped with research peptides because it stimulates GH and IGF-1. It is not FDA-approved for any indication and is sold in many settings as a research chemical; anti-aging, muscle gain, sleep, and fat-loss uses are not approved and have limited clinical outcome evidence. Major concerns include increased appetite, edema, insulin resistance or higher glucose, lethargy, carpal-tunnel-like symptoms, and potential risk in malignancy or heart failure-prone users.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This safety record covers a controlled, investigational, or otherwise out-of-scope substance. It remains available for reference, but it is not part of NutriStack's public supplement publication set.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
MK-677 (Ibutamoren) is an other most often used for raises gh and igf-1 in trials, increased fat-free mass in one older-adult trial without broad functional improvement, can increase appetite as a pharmacologic effect. NutriStack rates the overall evidence as insufficient. A typical adult dose is No FDA-approved dose; clinical trials commonly used 25 mg/day orally under supervision, but this is not a supplement dose, commonly taken as not recommended as a supplement; investigational oral drug only. This profile indexes 3 sources.
- Increased appetite
- Weight gain
- Edema
- Active malignancy or high tumor concern
- Pregnancy and breastfeeding
The bottom line
Evidence rating insufficient. Most-documented uses: raises gh and igf-1 in trials, increased fat-free mass in one older-adult trial without broad functional improvement, can increase appetite as a pharmacologic effect. 3 sources indexed (2008–2025), with 0 interaction records on file.
How it works, mechanistically.
Core mechanism
MK-677 activates the ghrelin or growth hormone secretagogue receptor, increasing pulsatile GH secretion and IGF-1 without being a peptide. Ghrelin receptor activation also increases hunger and can alter sleep architecture, fluid balance, insulin sensitivity, and weight. Longer trials show target engagement but not consistent functional benefit, and glucose or edema adverse effects are clinically important.2,1
Dosing & protocol.
Orally active small molecule. Product identity and purity are major concerns in research-chemical markets.
What it actually costs.
Real-world pricing across three quality tiers. Assumes Research chemical oral product.
Research-market products are not approved medicines and are not appropriate for self-treatment. Updated 2026-06-04.
Full safety detail.
Side effects
- Increased appetite
- Weight gain
- Edema
- Lethargy
- Joint pain
- Numbness or tingling
- Carpal-tunnel-like symptoms
- Increased fasting glucose
- Insulin resistance
Contraindications
- Active malignancy or high tumor concern
- Pregnancy and breastfeeding
- Diabetes or uncontrolled prediabetes without specialist supervision
- Heart failure, significant edema, or uncontrolled hypertension
- Competitive athletes subject to anti-doping rules
- Non-FDA-approved human use and research-chemical products3
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Randomized controlled trials
2- 1Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trialNass R et al. · Annals of Internal Medicine · 2008
MK-677 increased fat-free mass and IGF-1 but did not produce broad functional improvement.
- 2Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trialSevigny JJ et al. · Neurology · 2008
MK-677 increased IGF-1 but did not slow Alzheimer disease progression.
Reference material
1- 3The 2026 Prohibited List: International StandardWorld Anti-Doping Agency · World Anti-Doping Agency · 2025
Non-approved substances and GH secretagogues are prohibited in sport.
Common questions.
Quick answers about MK-677 (Ibutamoren), drawn from the data on this page.
What is MK-677 (Ibutamoren)?
MK-677, or ibutamoren, is an orally active non-peptide ghrelin receptor agonist commonly grouped with research peptides because it stimulates GH and IGF-1. It is not FDA-approved for any indication and is sold in many settings as a research chemical; anti-aging, muscle gain, sleep, and fat-loss uses are not approved and have limited clinical outcome evidence. Major concerns include increased appetite, edema, insulin resistance or higher glucose, lethargy, carpal-tunnel-like symptoms, and potential risk in malignancy or heart failure-prone users.
What is MK-677 (Ibutamoren) used for?
Commonly cited benefits of MK-677 (Ibutamoren) include: Raises GH and IGF-1 in trials; Increased fat-free mass in one older-adult trial without broad functional improvement; Can increase appetite as a pharmacologic effect; No FDA-approved therapeutic or wellness use. NutriStack rates the overall evidence as insufficient.
What is a typical dose of MK-677 (Ibutamoren)?
A typical adult dose of MK-677 (Ibutamoren) is No FDA-approved dose; clinical trials commonly used 25 mg/day orally under supervision, but this is not a supplement dose. The commonly recommended form is Not recommended as a supplement; investigational oral drug only. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of MK-677 (Ibutamoren)?
Reported side effects include increased appetite, weight gain, edema, lethargy, joint pain, numbness or tingling. This is educational information; check with a healthcare professional before use.
How strong is the evidence for MK-677 (Ibutamoren)?
NutriStack rates this as Insufficient, meaning the body of evidence reviewed in NutriStack's tiering framework. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
MK-677 (Ibutamoren) in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.