Important limitations
- Individual claims and source links have not yet completed editorial verification.
- Evidence level, applicable study model, formulation, route and population remain unassigned.
MK-677
MK-677, alternatively known as Ibutamoren or Oratrope, is an orally administered compound that acts as a specific agonist for the ghrelin receptor.
Dosing & scaling, explained
No mass-based amount example with adequate calculation context is available for this compound. This is educational source context, not a protocol or recommendation.
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No independently verified schedule
Evidence context
No clinical amount or schedule is inferred from this material. Source verification is pending, and every displayed amount remains educational context rather than guidance.
Storage, handling and interpretation
Product identity
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Storage & handling
Follow the product label, certificate and validated laboratory SOP; no universal storage assumption is applied here.
Prepared solutions
Label concentration and preparation date, use sterile technique where applicable, and follow a validated stability protocol.
Reported protocols for MK-677
What published studies and recent community write-ups report about amounts, timing and course length. 9 clinical and 3 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical9 rows | |||||
| Dose-ranging trial in healthy older adults32 healthy men and women aged 64-81 | 2, 10 or 25 mg (or placebo) | Once daily | Oral | Two study periods of 14 and 28 daysNot described | Journal of Clinical Endocrinology and Metabolism (PubMed)1996 |
| Two weeks at 25 mg raised the mean 24-hour growth hormone concentration by 97% by amplifying existing pulses, and IGF-1 climbed from 141 to 265 ng/mL by four weeks, back into the young-adult range. Fasting glucose also rose from 5.4 to 6.8 mmol/L at four weeks and prolactin increased 23%, while cortisol did not change. | |||||
| Sleep study in young and older adults8 young adults (18-30) and 6 older adults (65-71) | 5 or 25 mg (young); 2 then 25 mg (older) | Once daily at bedtime | Oral | 7-day periods (young) or 14-day periods (older)At least 14 days between periods | Neuroendocrinology (PubMed)1997 |
| At 25 mg, young subjects had about 50% more stage IV sleep and over 20% more REM sleep than on placebo, and older subjects had nearly 50% more REM sleep with shorter REM latency. Fourteen people in total took part, so the sleep benefit that community users prize rests on a very small base. | |||||
| Diet-induced catabolism crossover8 healthy volunteers aged 24-39 on an 18 kcal/kg per day diet | 25 mg | Once daily during the last 7 days of each 14-day diet period | Oral | 7 days of drug within each 14-day period14-21 day washout between periods | Journal of Clinical Endocrinology and Metabolism (PubMed)1998 |
| Nitrogen balance swung from about minus 1.5 g per day on placebo to plus 0.3 g per day on MK-677 while calories stayed restricted, and IGF-1 that had fallen with dieting rose to 264 ng/mL. The effect was measured over one week in eight people and the authors framed it as a lead for catabolic illness rather than for healthy adults. | |||||
| Two-month trial in obese men24 obese men aged 18-50 with BMI above 30 | 25 mg | Once daily | Oral | 8 weeksNone | Journal of Clinical Endocrinology and Metabolism (PubMed)1998 |
| IGF-1 rose about 40% and fat-free mass increased on both DXA and a four-compartment model, but total and visceral fat did not change and the rise in basal metabolic rate seen at two weeks had faded by eight. Oral glucose tolerance was impaired at both time points even though fasting glucose and insulin were unchanged. | |||||
| Postmenopausal osteoporosis trial with alendronate292 women aged 64-85 with low femoral neck bone density | 25 mg (alone or with alendronate 10 mg) | Once daily | Oral | 12 months, with bone density followed to 18 monthsNone | Journal of Clinical Endocrinology and Metabolism (PubMed)2001 |
| MK-677 raised IGF-1 by 39-45% and increased both bone formation and resorption markers, and adding it to alendronate improved femoral neck density by 4.2% versus 2.5% for alendronate alone. Spine, total hip and whole-body density were no better than with alendronate alone, and the authors weighed that against growth hormone side effects in the MK-677 groups. | |||||
| Two-year trial in healthy older adults65 healthy adults aged 60-81 at the University of Virginia | 25 mg (10 mg tablets available for blinded dose reduction) | Once daily between 7 and 9 a.m. | Oral | 12 months double-blind, then a second year with re-randomization (2 years total)None; four participants were dropped to 10 mg for raised glucose or joint pain | Annals of Internal Medicine (PubMed)2008 |
| Fat-free mass rose 1.1 kg on MK-677 while falling 0.5 kg on placebo, but visceral and total fat did not change, limb fat and body weight (plus 2.7 kg) increased, and the extra lean mass brought no gain in strength or function. Fasting glucose rose about 5 mg/dL, insulin sensitivity fell, cortisol increased and the common complaints were appetite, ankle swelling and muscle pain; the GH and IGF-1 response persisted through year two without tolerance. | |||||
| Alzheimer's disease trial (negative)563 adults with mild to moderate Alzheimer's disease | 25 mg | Once daily | Oral | 12 monthsNone | Neurology (PubMed)2008 |
| Serum IGF-1 rose 60% at six weeks and 73% at twelve months, proving the drug hit its target, yet none of the four clinical scales differed from placebo. This is the largest MK-677 trial ever run and it was clearly negative for its purpose. | |||||
| Hip fracture phase 2b trial (terminated early)123 elderly patients recovering from hip fracture | 25 mg | Once daily | Oral | 24 weeks plannedTrial stopped early | Archives of Gerontology and Geriatrics (PubMed)2011 |
| IGF-1 rose 51 ng/mL more than on placebo and gait speed improved slightly, but stair-climbing power and most other functional measures did not, and the study was terminated after a safety signal of congestive heart failure in a small number of treated patients. An earlier 161-patient, six-month trial in the same setting had also raised IGF-1 by 84% without clear functional benefit, and the FDA cites this heart failure signal in its compounding listing. | |||||
| Pediatric growth hormone deficiency, phase 2 (LUM-201)82 prepubertal children with moderate idiopathic growth hormone deficiency selected by a predictive marker test | 0.8, 1.6 or 3.2 mg/kg per day (comparator: injected growth hormone 34 mcg/kg per day) | Once daily | Oral | 6-month primary analysis, treatment continued to 24 monthsNone | Lumos Pharma2023 |
| The 1.6 mg/kg dose produced an annualized height velocity of 8.2 cm per year at six months and 8.0 at twelve, within the sponsor's 2 cm per year margin of injected growth hormone, and 3.2 mg/kg added little. These are company topline figures from an open-label study not designed to prove non-inferiority, and the program remains investigational. | |||||
| Community-reported3 rows | |||||
| Community bedtime protocol with step-up | 10 mg for weeks 1-2, then 15 mg, then 25 mg if glucose monitoring stays clean | Once daily at bedtime | Oral capsules (10 or 25 mg) or liquid (typically 25 mg/mL) | 8-16 weeks4-8 weeks off | Community resource2026 |
| This 2026 guide notes that the common 25 mg bedtime dose matches the two-year trial and that community cycling is more conservative than the continuous trial protocol because of insulin sensitivity. It describes 1-3 kg of water weight in the first month and tells readers that persistent pitting edema warrants stopping and a cardiac check, particularly over age 60. | |||||
| Community dose tiers and long-term low dose | 10 mg (low), 15 mg (standard) or 25 mg (high) | Once daily, 30 minutes before bed | Oral | 8-16 weeks on, or continuous at 10 mg4-8 weeks off, or no break at 10 mg with quarterly HbA1c checks | Community resource2026 |
| This protocol page frames 10 mg as the sleep and recovery dose and 25 mg as the mass dose, with hunger and water retention scaling with dose and fading after 2-4 weeks. It cites the two-year trial's rise in fasting glucose as the reason to cycle or to monitor, and lists diabetes, heart failure and active cancer as reasons not to use it. | |||||
| Aggregated community protocols | 25 mg standard; 10-15 mg beginner; 12.5-25 mg sleep-focused; 10-12.5 mg extended | Once daily, morning or before bed | Oral | 8-16 weeks (8-12 for beginners; 3-6 months for the extended low-dose pattern)Breaks between cycles are described as the recommended approach, though some users run continuously | Community resource2026 |
| Compiled from about 300 forum reports in early 2026, this page records that awareness of the hip fracture heart failure signal is patchy in the community and that some users take metformin or berberine to offset glucose effects. It points out that the two-year trial kept IGF-1 elevated without body composition gains, which undercuts the case for extended use. | |||||
How a course is commonly described
- Days 1-7Clinical
Growth hormone and IGF-1 rise from the first dose, and in the sleep study a week at 25 mg was enough to increase deep and REM sleep. Community reports put the appetite surge and deeper sleep in the first few nights, which is why most guides dose at bedtime.
- Weeks 2-4Clinical
IGF-1 reaches the young-adult range by two to four weeks at 25 mg, and this is also when fasting glucose was already higher in the dose-ranging trial. Community guides place water retention in the face, hands and ankles here and advise cutting sodium or dropping to 10 mg.
- Weeks 8-16: community cycle endCommunity-reported
Most community cycles stop between 8 and 16 weeks, then pause for 4-8 weeks. Guides give insulin sensitivity rather than receptor tolerance as the reason, since trials showed no loss of GH response over two years, and recommend fasting glucose every 4-6 weeks and HbA1c every 3 months while on 25 mg.
- Months 6-24: trial exposureClinical
The osteoporosis, Alzheimer's and healthy-aging trials ran 25 mg daily for 12 to 24 months without breaks. Over that span lean mass rose about 1 kg without functional gain, weight and limb fat went up, glucose and cortisol drifted higher, and the hip fracture study was halted for heart failure at under six months.
- StoppingCommunity-reported
No trial describes a taper. Community pages report that water retention clears within one to two weeks of stopping and that appetite normalizes, and the two-year trial's crossover arm showed body composition drifting back once participants moved to placebo.
- MK-677 has more human trial data than most compounds on this site, and nearly all of it used 25 mg once daily, so the community dose is not extrapolated. What the trials did not show is any functional or cognitive benefit, and the longest ones recorded higher glucose, lower insulin sensitivity, higher cortisol and, in frail patients, heart failure.
- Ibutamoren mesylate sits in the FDA's compounding Category 2 (503B since December 2022, 503A since September 2023) because of the heart failure signal in the hip fracture trial, and ibutamoren is prohibited at all times by WADA under S2.2.4. No regulator has approved it for any indication.
- Community cycling rules exist to manage blood sugar, not receptor fatigue: the trials found no tolerance to the GH response over two years. Products sold as MK-677 are unregulated research chemicals of unverified identity and dose, which is a different exposure from the Merck-manufactured tablets used in every trial above.
Sources for this section (15)
- Stimulation of the growth hormone (GH)-insulin-like growth factor I axis by daily oral administration of a GH secretogogue (MK-677) in healthy elderly subjects
- Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man
- MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism
- Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure
- Effect of alendronate and MK-677 (a growth hormone secretagogue), individually and in combination, on markers of bone turnover and bone mineral density in postmenopausal osteoporotic women
- The effects of MK-0677, an oral growth hormone secretagogue, in patients with hip fracture
- Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial
- Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial
- MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study
- Lumos Pharma Announces Topline Data from Phase 2 OraGrowtH210 and OraGrowtH212 Trials of LUM-201 in PGHD Met All Primary and Secondary Endpoints
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks
- The 2026 Prohibited List, World Anti-Doping Code
Plus 3 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
Overview
MK-677 (ibutamoren) is an orally active small molecule, not a peptide, that mimics ghrelin at the growth hormone secretagogue receptor and raises growth hormone and IGF-1 for roughly a day after each dose. Merck studied it through the late 1990s and 2000s in healthy older adults, obese men, dieting volunteers, postmenopausal women with osteoporosis, hip fracture patients and people with Alzheimer's disease, almost always at 25 mg once daily; it reliably restored IGF-1 to young-adult levels but did not improve function, failed in Alzheimer's disease, raised fasting glucose and cortisol, and a hip fracture trial was stopped early over congestive heart failure. It has never been approved for any use, Lumos Pharma is now testing it as LUM-201 for childhood growth hormone deficiency, the FDA lists ibutamoren mesylate in compounding Category 2 because of the heart failure signal, WADA prohibits it at all times, and it is sold online as a research chemical alongside SARMs.
What researchers are exploring
These themes organize the educational information currently available. Individual claims remain under source review and are not treatment claims.
- 1
MK-677 and Its Classification
Understanding MK-677's place among growth hormone secretagogues
- 2
Advantages of MK-677 Over SARMs
Benefits of MK-677 compared to selective androgen receptor modulators
- 3
MK-677 and Somatopause
Effects on age-related GH decline
- 4
MK-677 and Body Composition
Impact on lean mass, fat metabolism, and bone density
- 5
MK-677 and Bone Density
Effects on bone remodeling and fracture resistance
- 6
MK-677 and Neurological Function
Potential applications in Alzheimer's disease prevention
What is known and what still needs verification
Available context is organized without assigning unsupported study models or evidence grades.
- Not graded
MK-677 and Its Classification
Understanding MK-677's place among growth hormone secretagogues
- Not graded
Advantages of MK-677 Over SARMs
Benefits of MK-677 compared to selective androgen receptor modulators
Chemistry identifiers
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
Also listed as
Ibutamoren, MK-0677, L-163,191, Ibutamoren mesylate (the salt used in trials), LUM-201 (Lumos Pharma pediatric program code), UNII GJ0EGN38UL, CHEMBL13817, GTPL5867
InChIKey
UMUPQWIGCOZEOY-JOCHJYFZSA-N
IUPAC name
2-amino-2-methyl-N-[(2R)-1-(1-methylsulfonylspiro[2H-indole-3,4'-piperidine]-1'-yl)-1-oxo-3-phenylmethoxypropan-2-yl]propanamide
Limitations and unknowns
Sources
1 link carried over from the earlier page, awaiting verification.