Peptide LibraryMK-677 dosage in published studies and labels
These are the doses used for MK-677 in FDA labelling and published clinical studies, reported as each source states them, one row per regimen. They describe what was studied or approved for a specific population. They are not a recommendation, and none of them is a dose for any individual.
Research and educational reference only. This is not medical advice, and no figure on this page is a dosing recommendation.
Last checked against primary sources:
Studied regimens and sources
MK-677 (ibutamoren mesylate) has no approved dosage, but it has been studied in randomised human trials. The year-long trials gave 25 mg by mouth once daily, in Alzheimer's disease, postmenopausal osteoporosis and healthy older adults (the last for up to 2 years); shorter studies used 2–50 mg. It reliably raised growth hormone and IGF-1 and increased fat-free mass, but it did not slow Alzheimer's disease, did not improve most functional measures after hip fracture or strength and function in healthy older adults, and it raised fasting glucose and reduced insulin sensitivity. A hip-fracture trial was stopped early over a heart failure safety signal. MK-677 is not a peptide: it is an orally active small-molecule agonist of the ghrelin receptor.
Clinical Trial Evidence
| Human dosing established | Yes |
|---|---|
| Studied dose range | 2–50 mg once daily studied in adults; 25 mg once daily in the year-long trials |
| Route | Oral |
| Frequency | Once daily in every trial reviewed here; two sleep and hormone studies gave it at bedtime |
| Duration studied | 4 days to 2 years; 12 months in the Alzheimer's and osteoporosis trials, up to 2 years in healthy older adults |
| Titration | The year-long trials gave 25 mg daily without escalation. In the 2-year trial the dose was reduced, blinded, to 10 mg daily in 4 participants because of raised fasting glucose or joint pain. |
| Half-life | Not reported in an indexed human study; the trials dosed once daily |
| Evidence level | Clinical Trial Evidence |
| Last reviewed | 2026-10-05 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| Two-year trial in healthy older adults (Nass et al., 2008)Clinical trial · Double-blind randomised placebo-controlled modified-crossover trial | 65 healthy adults aged 60–81: men, and women on or off hormone replacement therapy | 25 mg (reduced, blinded, to 10 mg daily in 4 participants) | Oral | Once daily | 12 months for the primary endpoints; 2 years in total, modified crossover | Growth hormone and IGF-1 rose to young-adult levels. Fat-free mass increased 1.1 kg against a mean 0.5 kg fall on placebo; abdominal visceral fat and total fat mass did not differ from placebo, and strength and function did not change. Body weight rose 2.7 kg, fasting glucose rose 0.3 mmol/L and insulin sensitivity fell. | Nass R et al. Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trial. Ann Intern Med. 2008. |
| Alzheimer's disease, 12 months (Sevigny et al., 2008; NCT00074529)Clinical trial · Multicentre double-blind randomised placebo-controlled trial | 563 patients with mild to moderate Alzheimer's disease randomised; 416 completed 12 months | 25 mg | Oral | Once daily | 12 months | Serum IGF-1 rose 60.1% at 6 weeks and 72.9% at 12 months, but there was no difference from placebo on CIBIC-plus, ADAS-Cog, ADCS-ADL or CDR sum of boxes. The authors concluded it was ineffective at slowing progression. | Sevigny JJ et al. Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trial. Neurology. 2008. |
| Hip fracture, phase IIb, terminated early (Adunsky et al., 2011; NCT00128115)Clinical trial · Phase IIb multicentre double-blind randomised placebo-controlled trial | 123 elderly patients recovering from hip fracture (62 on MK-0677, 61 on placebo) | 25 mg | Oral | Daily | 24 weeks planned; the trial was terminated early | IGF-1 rose 51.4 ng/mL versus placebo and gait speed improved, but stair-climbing power and most other functional measures did not. The trial was terminated early because of a safety signal of congestive heart failure in a limited number of patients, and the authors concluded MK-0677 has an unfavourable safety profile in this population. | Adunsky A et al. MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb study. Arch Gerontol Geriatr. 2011. |
| Postmenopausal osteoporosis, with and without alendronate (Murphy et al., 2001)Clinical trial · Multicentre double-blind randomised placebo-controlled trial | 292 women aged 64–85 with low femoral neck bone mineral density | 25 mg, alone or with alendronate 10 mg | Oral | Once daily | 12 months, with bone mineral density followed to 18 months | IGF-1 rose 39–45% and bone turnover markers increased. Combined with alendronate it raised femoral neck bone mineral density more than alendronate alone (4.2% vs 2.5%), but not lumbar spine, total hip or total body density. Growth hormone-mediated side effects were reported in the MK-677 groups. | Murphy MG et al. 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. J Clin Endocrinol Metab. 2001. |
| Obese men, 8 weeks (Svensson et al., 1998)Clinical trial · Double-blind randomised placebo-controlled parallel-group trial | 24 otherwise healthy obese men aged 18–50 (12 on MK-677, 12 on placebo) | 25 mg | Oral | Daily | 8 weeks | IGF-1 rose about 40% and fat-free mass increased; total and visceral fat did not change significantly. Basal metabolic rate rose at 2 weeks but not at 8 weeks. Oral glucose tolerance tests showed impaired glucose homeostasis at 2 and 8 weeks. | Svensson J et al. Two-month treatment of obese subjects with the oral growth hormone (GH) secretagogue MK-677 increases GH secretion, fat-free mass, and energy expenditure. J Clin Endocrinol Metab. 1998. |
| Dose-ranging study in healthy older adults (Chapman et al., 1996)Clinical trial · Double-blind randomised placebo-controlled dose-ranging trial | 32 healthy adults aged 64–81 | 2, 10 or 25 mg, or placebo | Oral | Once daily | Two study periods of 14 and 28 days | Growth hormone rose in a dose-dependent manner; 25 mg raised mean 24-hour growth hormone by 97% and restored IGF-1 to young-adult levels. Fasting glucose rose from 5.4 to 6.8 mmol/L at 4 weeks. | Chapman IM et al. 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. J Clin Endocrinol Metab. 1996. |
| Adults with childhood-onset growth hormone deficiency, rising dose (Chapman et al., 1997)Clinical trial · Double-blind rising-dose study with a placebo crossover arm | 9 severely growth hormone-deficient men aged 17–34, treated with growth hormone in childhood | 10 mg, then 50 mg in 5 participants; the other 4 received placebo and 10 mg in crossover | Oral | Once daily | 4 days per treatment period, two periods at least 28 days apart | IGF-1 rose 52% on 10 mg and 79% on 50 mg, and 24-hour mean growth hormone rose 79–82%. Fasting and postprandial insulin and postprandial glucose increased. | Chapman IM et al. Oral administration of growth hormone (GH) releasing peptide-mimetic MK-677 stimulates the GH/insulin-like growth factor-I axis in selected GH-deficient adults. J Clin Endocrinol Metab. 1997. |
| Sleep study in young and older adults (Copinschi et al., 1997)Clinical trial · Double-blind placebo-controlled crossover in young adults; sequential dosing without placebo in older adults | 8 healthy young adults aged 18–30 and 6 older adults aged 65–71 | Young adults: 5 mg, 25 mg and placebo in crossover. Older adults: 2 mg, then 25 mg | Oral, at bedtime | Once daily at bedtime | 7-day periods in young adults; 14-day periods in older adults | In young adults 25 mg increased stage IV sleep by about 50% and REM sleep by more than 20% versus placebo. In older adults REM sleep rose by nearly 50% and REM latency fell; the older group had no placebo period. | Copinschi G et al. Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man. Neuroendocrinology. 1997. |
| NCT00395291 — haemodialysis patients, crossover, results postedClinical trial · Randomised blinded placebo-controlled crossover pilot study with posted results | Adults with end-stage renal disease on haemodialysis (26 started treatment, 22 completed both periods) | 25 mg | Oral | Once daily | About 30 days per period, crossed over with placebo after a 30-day washout | IGF-1 rose by a mean 92.7 ng/mL after MK-0677 versus 6.7 ng/mL after placebo (p < 0.001). The posted serious adverse events for the MK-0677 period include one case of congestive heart failure; the published report (Campbell et al., 2018) found no serious adverse effects attributable to MK-0677. | NCT00395291 — Growth Hormone Secretagogue MK-0677 Effect on IGF-1 Levels in ESRD Patients |
| NCT05364684 — non-alcoholic fatty liver disease pilot, results postedClinical trial · Single-arm open-label phase 2 pilot study with posted results | 12 adults aged 21–60 with a BMI of 25 or more and non-alcoholic fatty liver disease; 7 completed | 25 mg, given as LUM-201 (ibutamoren mesylate) | Oral | Once daily | 6 months | Liver fat measured by MR spectroscopy did not fall: the mean change was +3.9 percentage points (SD 6.7; p = 0.4) in the 7 who completed. 7 of 12 reported increased appetite and 4 of 12 hyperglycaemia; there were no serious adverse events. | NCT05364684 — The Impact of Ibutamoren on Nonalcoholic Fatty Liver Disease |
| NCT04614337 — OraGrowtH210, LUM-201 in children with growth hormone deficiency, results postedClinical trial · Phase 2 randomised open-label active-controlled trial with posted results | Prepubertal children aged 3–12 with idiopathic growth hormone deficiency, not previously treated (18, 22 and 22 on the three LUM-201 doses; 20 on injected growth hormone) | 0.8, 1.6 or 3.2 mg/kg per day, given as LUM-201 (ibutamoren mesylate) | Oral | Once daily | 6-month primary analysis within a 24-month study | Six-month annualised height velocity was 6.8, 8.2 and 7.7 cm per year on the three LUM-201 doses, against 10.6 cm per year on daily injected growth hormone at 34 mcg/kg. | NCT04614337 — Phase 2 Study of LUM-201 in Children With Growth Hormone Deficiency (OraGrowtH210 Trial) |
| NCT06948214 — phase 3, LUM-201 in children with growth hormone deficiency, recruitingClinical trial · Phase 3 randomised placebo-controlled trial, recruiting | Prepubertal children aged 3–11 with growth hormone deficiency, not previously treated (150 planned) | 1.6 mg/kg per day, given as LUM-201 (ibutamoren mesylate) | Oral | Once daily | 12 months | Annualised height velocity at 12 months versus placebo. No results have been posted. | NCT06948214 — Phase 3 Study of LUM-201 in Children With Growth Hormone Deficiency |
Where sources disagree
- MK-677 is not a peptide. Ibutamoren mesylate is an orally active small molecule that activates the ghrelin receptor, and the trials themselves describe it as a nonpeptide growth hormone secretagogue. It is sold alongside peptides but shares neither their structure nor their handling: it is swallowed, not injected, and there is nothing to reconstitute.
- No regulator has approved ibutamoren for any use. Merck took it through phase 2 trials as MK-0677, none of which led to an approved product, and it is now in development by Lumos Pharma as LUM-201 for children with growth hormone deficiency. DailyMed does carry two listings for ibutamoren mesylate powder from AX Pharmaceutical, but both are bulk-ingredient listings, categorised as a bulk ingredient for animal drug compounding, with no prescribing information or dose. A DailyMed listing is not an FDA approval.
- Oral doses of 10–25 mg once daily are widely published for MK-677, and unlike most compounds sold alongside peptides those figures do match trial doses: 25 mg once daily is the dose in every year-long trial (Nass 2008, Sevigny 2008, Murphy 2001), and 10 mg appears in short dose-ranging studies. What does not carry over is the population. The trials enrolled older adults and people with obesity, Alzheimer's disease, hip fracture, osteoporosis, kidney failure or growth hormone deficiency; the only studies in healthy young adults that this review found lasted 7 days.
- The fat-free mass gain is real in the trials but did not translate into function. In healthy older adults fat-free mass rose 1.1 kg over a year while strength and function did not change, abdominal visceral fat and total fat mass did not differ from placebo, and body weight rose 2.7 kg. In obese men over 8 weeks fat-free mass rose while total and visceral fat were unchanged.
- Both large patient trials missed their goals. In 563 people with Alzheimer's disease, 12 months of 25 mg daily raised IGF-1 by 72.9% but did not slow decline on any of the four cognitive, functional or global measures. After hip fracture, IGF-1 rose but most functional measures did not improve, and the phase IIb trial was terminated early because of a safety signal of congestive heart failure. An earlier 161-patient hip-fracture trial (Bach et al., 2004) also found no significant difference in functional performance, and a 24-week fibromyalgia trial of 25 mg daily (NCT00116129) completed in 2008 without posting results.
- The trials report consistent metabolic effects. Over a year in healthy older adults fasting glucose rose 0.3 mmol/L on average, HbA1c rose and insulin sensitivity fell, and the dose was cut to 10 mg in two participants because of raised fasting glucose; glucose tolerance was impaired in obese men within 2 weeks. Increased appetite, mild transient leg oedema and muscle pain were the most frequent side effects. In the fatty liver pilot, 7 of 12 participants reported increased appetite and 4 had hyperglycaemia.
- A half-life of about 24 hours is widely quoted for MK-677. No primary source reviewed here states a human half-life: the Merck assay paper describes mapping the plasma time course after a single 5 mg dose but reports no half-life in its abstract, so none is given here. The trials simply dosed once daily.
- Current development is paediatric and weight-based. As LUM-201, ibutamoren was given at 0.8–3.2 mg/kg once daily to children with growth hormone deficiency, and no dose matched daily injected growth hormone on 6-month height velocity. Those mg/kg doses do not convert into the fixed adult doses above.
- Case reports in people taking MK-677 as a performance-enhancing supplement describe liver injury that resolved after stopping, and gynaecomastia with hypogonadism from supplements that also contained RAD-140, cardarine and undisclosed hormones. Single case reports do not establish cause, but they show that what is sold as MK-677 is not necessarily what the trials administered.