MK-677
WELL RESEARCHEDOral growth hormone secretagogue | Ibutamoren
By the INFOPEPTIDOS editorial team · content based on scientific literature.
Updated: August 2026.
Key points
- What it is: oral growth hormone secretagogue (ghrelin receptor agonist).
- Main use: muscle mass, appetite, deep sleep and recovery.
- Typical dose: 10–25 mg once a day, orally.
- Key result: raises GH and IGF-1 steadily for 24 h with a single daily dose.
- Common effects: increased appetite, fluid retention and mild drowsiness.
- Comparison: unlike injectable GH peptides, it is oral and long-acting.
- Status: not FDA-approved (research compound).
Technical data: Molecular formula C27H36N4O5S · Molecular weight 528.7 g/mol. Source: PubChem.
Overview
What is MK-677?
MK-677 (ibutamoren) is an orally active growth hormone secretagogue that mimics ghrelin. Unlike injectable GH-axis peptides, it is taken as a tablet or liquid and steadily raises growth hormone and IGF-1 levels for 24 hours with a single daily dose.
Key benefits
Sustained GH and IGF-1 elevation without injections, with gains in lean mass, bone density, deep sleep and recovery. Its oral convenience makes it very popular versus injectable secretagogues.
Mechanism of action
It acts as a ghrelin receptor (GHS-R) agonist in the pituitary and hypothalamus, stimulating natural GH pulses without suppressing the body's own production. It does not markedly affect cortisol.
Quick start guide
Dosing protocol
| Phase | Dose | Frequency | Duration |
|---|---|---|---|
| Standard | 10–25 mg | 1 time/day (oral) | 8–16 weeks |
Oral route. Start at the low dose to assess appetite and fluid retention. The specific dose must be assessed by a healthcare professional.
🧮 Calculate your exact syringe dose →MK-677 vs injectable secretagogues
| MK-677 | CJC-1295 / Ipamorelin | |
|---|---|---|
| Route | Oral | Injectable (SC) |
| Frequency | Once a day | 1-3 times a day |
| Half-life | Long (~24 h) | Short |
| Convenience | High | Medium |
⚠️ Who should NOT use it
- People with diabetes or insulin resistance (it can raise glucose) — consult first.
- People with active cancer — raising GH/IGF-1 is discouraged.
- Heart failure or edema.
- Pregnancy or breastfeeding.
- Always under the supervision of a healthcare professional.
What to expect
- Week 1-2: increased appetite and deeper sleep.
- Week 2-4: better recovery and some fluid retention.
- Week 4-8: lean mass gains and improved skin tone.
- Week 8-16: sustained muscle gains and greater bone density.
- Side effects: hunger, mild bloating and drowsiness.
- Most effective for: clean bulking, recovery and sleep optimization.
Side effects & safety
- Marked increase in appetite, especially at the start.
- Fluid retention and mild swelling in hands or ankles.
- Drowsiness; taking it before bed helps.
- Possible rise in blood glucose: monitor in prediabetes or diabetes.
- Temporary tingling or numbness in the hands.
- Allergic reaction: rash, itching or swelling.
- Significant swelling, difficulty breathing or signs of heart failure.
- Excessive thirst or urination, or persistently high glucose.
- Severe numbness or tingling in the hands (carpal tunnel).
- If you are pregnant, breastfeeding or have active cancer.
Frequently asked questions
What is MK-677?
MK-677 (ibutamoren) is an oral growth hormone secretagogue that activates the ghrelin receptor and raises GH and IGF-1 for 24 hours.
What is MK-677 used for?
It is researched to increase muscle mass and improve deep sleep, bone density and recovery.
What is the usual MK-677 dose?
Most commonly 10–25 mg once a day, orally. The regimen should be assessed by a professional.
Is MK-677 injected?
No; it is oral (tablet or liquid), which sets it apart from injectable secretagogues such as CJC-1295 or Ipamorelin.
What are the side effects of MK-677?
The most common are increased appetite, fluid retention, drowsiness and a possible rise in glucose.
Is MK-677 approved?
It is not FDA-approved for human use; it is a research compound.
Research areas
- Muscle mass
- Deep sleep
- Bone density
- Recovery
- Growth hormone stimulation
Related peptides
- CJC-1295 — Injectable GHRH analog of the GH axis.
- Ipamorelin — Selective GHRP; injectable secretagogue.
- Sermorelin — GHRH 1-29 analog.
Related articles
Related topics
- MK-677 for muscle mass
- MK-677 and sleep
- MK-677 dose
- MK-677 side effects
- MK-677 and appetite
- MK-677 cycle
Summary
What it is: Oral GH secretagogue (ghrelin agonist).
How it is researched: Oral, 10-25 mg once a day.
Key features: Raises GH and IGF-1 for 24 h without injections. Not FDA-approved.
Related peptides: CJC-1295, Ipamorelin and Sermorelin.
References
- Murphy MG et al. (1998). MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism. J Clin Endocrinol Metab. PubMed · DOI
- Tewari K et al. (2026). Peptide Supplements and Their Therapeutic Applications in Sports Medicine. Am J Sports Med. PubMed · DOI
- Kintz P et al. (2026). Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: II. Case example with ibutamoren (MK-677), a growth hormone secretagogue. Clin Chim Acta. PubMed · DOI
- Cardaci TD et al. (2022). LGD-4033 and MK-677 use impacts body composition, circulating biomarkers, and skeletal muscle androgenic hormone and receptor content: A case report. Exp Physiol. PubMed · DOI
Studies compiled from PubMed for informational purposes; many are preclinical or research-stage and do not constitute medical advice.