Ibutamoren

ID: ibutamoren

Aliases: MK-677, MK-0677, LUM-201, Nutrobal

Type: compound

Route/form: oral

Status: investigational_or_research

Evidence level: human RCT

Best data tier: human controlled/review

Support scope: human

Source types: case_report, human_rct

Linked sources: 4

Broad outcomes: Brain / mood / sleep, Fat loss / metabolic health, Hormones / fertility / sexual health, Muscle growth / performance / recovery, PEDs / AAS / thermogenics

Reading note: These are curation notes anchored to linked sources, not a clinical recommendation or protocol.

Targets / mechanism

• ghrelin receptor agonist
• growth hormone secretagogue
• GH/IGF-1 axis

Optimization domains

• SARM adjacent
• growth hormone
• body composition
• sleep
• metabolic

Research basis

• MK-677 is mechanistically a ghrelin receptor agonist and oral GH secretagogue, not a SARM.
• Randomized human studies show GH/IGF-1, fat-free-mass, catabolism, and sleep-architecture signals.
• The oral route and endocrine biomarker response make it a useful comparator to injectable GH secretagogues and somatropin.

Limits, risks, and missing evidence

• Lean-mass signals can include water and do not automatically imply strength or functional benefit.
• Hunger, edema, insulin resistance/glucose effects, sleepiness, and endocrine interactions can dominate practical risk.
• Case-report biomarker changes from combined use should not be treated as clean MK-677 efficacy data.

Risk flags

• not a SARM
• GH IGF axis
• glucose
• edema
• unapproved context

Linked papers, labels, and reviews

1. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults
   human_rct / pubmed_mk677_older_adults_2008
   Two-year randomized trial of MK-677/ibutamoren in older adults.
2. MK-677 reverses diet-induced catabolism
   human_rct / pubmed_mk677_catabolism_1998
   Randomized human study of oral GH secretagogue MK-677 in diet-induced catabolism.
3. Prolonged oral treatment with MK-677 improves sleep quality in man
   human_rct / pubmed_mk677_sleep_1997
   Human sleep/GH-axis study for MK-677; useful because ghrelin/GH effects can include sleep architecture and appetite/glucose tradeoffs.
4. LGD-4033 and MK-677 use impacts body composition and circulating biomarkers
   case_report / pubmed_lgd_mk677_case_report_2022
   Self-administration case report with body composition, lipid, liver enzyme, and hormone changes.