Quickstart highlights
Dosing & reconstitution guide
This product is supplied ready to use; no reconstitution is required.
Protocol overview
Duration
8–16 weeks
Route
Oral
Timing
Before bed (less daytime lethargy)
Dosing protocol in research
| Phase | Dose | Frequency |
|---|---|---|
| Start | 10 mg | once daily |
| Standard (studies) | 25 mg | once daily |
Values as described in literature and research protocols; not dosing advice.
Storage instructions
- Store dry, cool and dark in the original packaging.
- Avoid repeated freezing and thawing.
Important notes
- Not a peptide but an oral secretagogue.
- On the WADA prohibited list.
How this works
MK-677, also known as ibutamoren, is a non-peptide compound that mimics the action of the hunger hormone ghrelin. Merck & Co originally developed the substance for research into muscle-wasting conditions and growth hormone deficiency. It is studied because, unlike most growth hormone secretagogues, it does not require injection.
The substance binds to the ghrelin receptor (GHS-R) in the hypothalamus and the pituitary gland. This binding activates a signaling pathway that increases the pulsatile release of endogenous growth hormone (GH). Subsequently, this leads to an increase in Insulin-like Growth Factor 1 (IGF-1) in the blood. Unlike exogenous growth hormone, MK-677 does not disrupt the natural pulsation of GH. The compound has a half-life of approximately 24 hours, meaning a once-daily dose is sufficient for stable levels. It generally does not significantly affect cortisol levels during long-term use.
Human studies on MK-677 have been conducted for up to two years, including in elderly patients with hip fractures and patients with growth hormone deficiency. Researchers observed increases in bone density and lean mass, but no significant change in total fat mass. The substance is on the WADA prohibited list as a 'growth hormone secretagogue' and is not approved for medical use by the EMA or FDA. Long-term effects on cardiovascular health in healthy adults remain an open question in scientific literature.
Potential benefits & side effects
Effects described in research
- Increase in lean mass (human studies)
- Possibly deeper sleep
- Raised IGF-1
Common side effects
- Strongly increased appetite
- Water retention
- Lethargy
- Raised fasting glucose
Common side effects include significantly increased appetite and temporary water retention in the extremities. Studies also report an increase in fasting blood sugar levels and reduced insulin sensitivity, posing risks to glucose metabolism. Some users report lethargy and intense dreams during research.
Contraindications
- Pregnancy or breastfeeding
- Active or prior cancer
- Under 18 years of age
- Uncontrolled diabetes
Lifestyle factors
- Administration on an empty stomach (2 h after / 30 min before food) is most often described.
- Carbohydrates and fat around administration blunt the GH pulse.
- Adequate sleep supports natural nocturnal GH release.
Intake
- Take the tablet with water at the same time each day.
- Bedtime intake is often described to limit daytime lethargy.
Recommended source
Quality varies widely between suppliers. Look for an independent HPLC/MS lab report per batch, purity ≥ 98% and clear storage and shipping conditions.
As a reference we use the MK-677 (Ibutamoren) from PeptideWinkel, which publishes lab reports per batch.
Ask a question about MK-677 (Ibutamoren)
Answer based on our catalogue. Not medical advice — products are for research purposes only.
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Frequently asked questions
Do I need to inject MK-677?
No, ibutamoren is orally bioavailable. In scientific research, it is usually administered as a liquid or capsule.
Is MK-677 a SARM?
No, MK-677 is often mislabeled as a SARM, but it acts on the ghrelin receptor and not the androgen receptor.
What is the effect on blood sugar?
Research shows that MK-677 can increase fasting blood glucose and decrease insulin sensitivity, necessitating monitoring in clinical settings.