MK-677 (Ibutamoren)
Get a source-linked, educational explanation from this profile.
Complete Research Guide
Open each section for the available evidence. Gaps are stated rather than inferred.
Overview
MK-677 (Ibutamoren) is listed as endocrine / gh secretagogue.
- •GH/IGF-1 elevation
- •Body composition
- •Bone density
- •Sleep quality
Regulatory status: Not FDA-approved; investigational IND (Merck).
Structure & Properties
Compound: MK-677 (Ibutamoren); also known as Nutrobal, MK-0677.
Pharmacologic class: Endocrine / GH Secretagogue.
Known delivery routes: Oral.
Sequence, molecular weight, salt form, and excipient details are formulation-specific and are not listed unless verified by a manufacturer or laboratory COA.
How It Works
Oral ghrelin mimetic / GHS-R1a agonist — selectively stimulates GH and IGF-1; oral bioavailability; increases REM sleep.
- •Sustained IGF-1 elevation
- •Oral dosing convenience
- •Improved sleep depth
Human Research
Evidence grade: Pre-clinical / Observational
Evidence is primarily preclinical or observational; human effectiveness and long-term safety are not established.
Laboratory Research
Phase II/III completed; not submitted for approval
Preclinical findings describe biological plausibility, not proven benefit in people. Animal and laboratory doses do not translate directly to human use.
Processing & Interactions
Timing and exposure
Once daily, evening — aligns with sleep-onset GH pulse and helps offset next-day appetite. Take with or without food; some prefer with a small carb snack to reduce vivid dreams.
Potential interactions and combinations to avoid
- •GHRPs (Ipamorelin, GHRP-2/6, Hexarelin) — additive ghrelin activation
- •Insulin sensitizers without glucose monitoring — MK-677 lowers insulin sensitivity
Absorption, half-life, metabolism, and clearance can vary by formulation and route. Use prescribing information when an approved product exists.
Safety & Precautions
Known or reported risks
- •Insulin resistance
- •Water retention
- •Increased appetite
- •Lethargy
- •IGF-1 oncogenicity concern
Contraindications
- •Type 2 diabetes (caution)
- •Active malignancy
- •Heart failure
- •Pregnancy
- •Active malignancy or history of hormone-sensitive tumor (GH/IGF-1 axis stimulation)
- •Active or untreated diabetic retinopathy
- •Insulin resistance, prediabetes, or poorly controlled type 2 diabetes
- •Untreated hypothyroidism or uncorrected adrenal insufficiency
- •Acromegaly, pituitary adenoma, or intracranial hypertension
- •Carpal tunnel syndrome, peripheral edema, or fluid-retentive heart failure
- •Critical illness after acute surgery, trauma, or respiratory failure
- •Severe obstructive sleep apnea (may worsen with soft-tissue growth)
- •Congestive heart failure or reduced ejection fraction
- •Elevated fasting glucose or HbA1c above target
- •Increased appetite risk in binge-eating disorder
- •Not FDA-approved for human therapeutic use — no verified purity, sterility, or potency standards
- •Immunocompromised or transplant patients (unverified sterility and immunogenicity risk)
- •Concurrent participation in drug-tested sport (WADA prohibited or non-cleared substance)
- •Known hypersensitivity or prior reaction to this compound or any excipient/diluent
- •Pregnancy, attempting conception, or breastfeeding unless prescribed and monitored by a physician
- •Children and adolescents with open growth plates (unless under specialist endocrine care)
- •Active or recently treated malignancy without oncology clearance
- •Use without a confirmed diagnosis, baseline labs, and licensed clinical supervision
Unknown long-term toxicity should be assumed where controlled human data are limited. Seek urgent care for a severe or unexpected reaction.
Administration & Studied Formulations
Reference range: 10–25 mg/day
Frequency: Once daily (evening)
Cycling: 8–12 weeks on / 4 weeks off; monitor IGF-1 and glucose.
Oral
Once daily evening.
Capsule or liquid. With or without food; small carb snack can reduce vivid dreams.
Dosing information is educational context, not a personal recommendation. Approved products must follow their label and prescriber instructions.
Applications & Related Therapies
Potentially complementary measures
- •Standalone works well; short cycles with CJC-1295 acceptable
Clinical use should account for diagnosis, approved alternatives, nutrition, activity, sleep, rehabilitation, current medicines, and appropriate monitoring.
Expect fluid retention and appetite increase in first 2–3 weeks.
Cases, Considerations & Ethics
Decision framework: establish the clinical goal, confirm evidence quality and legal status, screen contraindications and interactions, compare approved alternatives, define monitoring and stopping criteria, and use shared decision-making with a licensed clinician.
Case evidence: individual reports cannot establish safety or effectiveness and should not outweigh controlled trials.
Ethics: informed consent should distinguish established care from experimental use, disclose uncertainty and cost, avoid overstated claims, and never substitute research products for medically necessary care.
What is MK-677 (Ibutamoren)?
In plain words
MK-677 is an experimental compound taken by mouth that copies a signal from ghrelin, a hormone involved in hunger and growth hormone release. It prompts the body to release more growth hormone and increase IGF-1, a hormone that helps tissues grow. Researchers study its effects on hormone levels, muscle and fat balance, and sleep. It is not FDA-approved and can cause fluid buildup, increased hunger, tiredness, and reduced ability to control blood sugar.
Technical definition
MK-677 (ibutamoren, also called MK-0677 or Nutrobal) is an orally active, synthetic nonpeptide growth hormone secretagogue that mimics ghrelin by activating the GHS-R1a receptor. This action stimulates endogenous growth hormone (GH) secretion and raises insulin-like growth factor 1 (IGF-1); effects on body composition and sleep architecture, including REM sleep, have been studied. It is an investigational compound and is not FDA-approved.
Function
Dosing
Recommended Time of Day
Before bed — limits daytime hunger and leverages the overnight GH pulse.
See “Timing & Interactions” below for full fasted/fed circumstances, what to avoid combining, and what pairs well.
Administration & Technique
Injection & Application Sites
MK-677 (Ibutamoren) has no injection site — see the routes below.
Diagram is a general illustration, not a medical instruction. Rotate sites every injection, keep 1 in (2.5 cm) between recent sites, and avoid scars, moles, bruises and the navel area.
Cycling
8–12 weeks on / 4 weeks off; monitor IGF-1 and glucose.
Timing & Interactions
- ·GHRPs (Ipamorelin, GHRP-2/6, Hexarelin) — additive ghrelin activation
- ·Insulin sensitizers without glucose monitoring — MK-677 lowers insulin sensitivity
- ·Standalone works well; short cycles with CJC-1295 acceptable
Storage & Reconstitution
Reconstitution Calculator
1 mL = 100 units on a standard U-100 insulin syringe. Draw to the nearest 0.5 unit and confirm dosing with a clinician before injection.
Your Notes
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Benefits
- ·Sustained IGF-1 elevation
- ·Oral dosing convenience
- ·Improved sleep depth
Risks
- ·Insulin resistance
- ·Water retention
- ·Increased appetite
- ·Lethargy
- ·IGF-1 oncogenicity concern
Contraindications
- ·Type 2 diabetes (caution)
- ·Active malignancy
- ·Heart failure
- ·Pregnancy
- ·Active malignancy or history of hormone-sensitive tumor (GH/IGF-1 axis stimulation)
- ·Active or untreated diabetic retinopathy
- ·Insulin resistance, prediabetes, or poorly controlled type 2 diabetes
- ·Untreated hypothyroidism or uncorrected adrenal insufficiency
- ·Acromegaly, pituitary adenoma, or intracranial hypertension
- ·Carpal tunnel syndrome, peripheral edema, or fluid-retentive heart failure
- ·Critical illness after acute surgery, trauma, or respiratory failure
- ·Severe obstructive sleep apnea (may worsen with soft-tissue growth)
- ·Congestive heart failure or reduced ejection fraction
- ·Elevated fasting glucose or HbA1c above target
- ·Increased appetite risk in binge-eating disorder
- ·Not FDA-approved for human therapeutic use — no verified purity, sterility, or potency standards
- ·Immunocompromised or transplant patients (unverified sterility and immunogenicity risk)
- ·Concurrent participation in drug-tested sport (WADA prohibited or non-cleared substance)
- ·Known hypersensitivity or prior reaction to this compound or any excipient/diluent
- ·Pregnancy, attempting conception, or breastfeeding unless prescribed and monitored by a physician
- ·Children and adolescents with open growth plates (unless under specialist endocrine care)
- ·Active or recently treated malignancy without oncology clearance
- ·Use without a confirmed diagnosis, baseline labs, and licensed clinical supervision
Regulatory
Not FDA-approved; investigational IND (Merck)
Veterinary Use (Pets)
No established veterinary protocol for MK-677 (Ibutamoren). Consult a licensed veterinarian before considering off-label use in any species.
Full veterinary reference →Functional Groups
Cited Works
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