Research peptides

MK-677 Dosage: Common Protocol and What Trials Used

MK-677 dosage: the 12.5-25 mg oral common protocol, and the 25 mg/day figure three published human trials actually used, with what they found.

Written bySebastian Hunter, Founder and EditorI'm a 42-year-old senior advisor and distance runner who came to peptides as a sceptic. I'm not a doctor: I read the research, run my own experiment and keep honest notes. Read full bio

Published September 27, 2026

The short version

MK-677 has no FDA-approved dose, because it has no approved product. Community and vendor dosing guides most often describe 12.5-25 mg by mouth once daily, commonly before bed, for an 8-12 week cycle with a 4-week break. That is common practice, not trial-established. Its upper bound matches the 25 mg the published 2008 trial used, though that trial dosed each morning rather than at bedtime. Trials tested older adults and obese men, not the younger, muscle-focused people most vendors market it to.

The common-practice protocol is 12.5-25 mg by mouth once daily for 8-12 weeks, then a 4-week break, dosed at bedtime rather than on the 2008 trial's morning schedule. It is not trial-established.
All three published human trials used 25 mg once daily, orally. Current dosing guides converge on the same figure.
One trial dose-ranged 2, 10 and 25 mg/day and found 25 mg produced the largest hormone response.
The longest trial ran 2 years in healthy adults aged 60-81, not the younger, muscle-focused people most vendors market to.

MK-677 has no FDA-approved dose, because it has no approved product. This page reports the dose three published human trials used, in the populations they studied. It is not a recommendation. For what MK-677 is, its mechanism and its legal status, see the main MK-677 page.

US legal status - Research use only

Sold for laboratory research use only. Not approved by the FDA for human use, and cannot be lawfully marketed as a supplement or a medicine. Products sold this way are not made to pharmaceutical quality standards, and their contents are not verified by anyone.

MK-677 dosage: the common protocol

Community and vendor dosing guides most often describe 12.5-25 mg by mouth once daily, commonly before bed. The cycle is 8-12 weeks with a 4-week break between cycles. This is common practice, not a dose any trial or regulator has established. The trial that established the 25 mg figure dosed it each morning, continuously with no cycle-off. Common practice instead moves dosing to bedtime and cycles it.

Common protocol

What is commonly used, not a dose established in trials. No regulator has set a dose for MK-677. Sources differ, so the ranges below span them.

Dose: 12.5-25 mg
How often: once daily by mouth; the published 2008 trial dosed each morning, while compounding-pharmacy protocols commonly move dosing to before bed
Route: By mouth
Cycle length: 8-12 weeks
Break between cycles: 4 weeks
Timing: Once daily. The randomized trial that established the 25 mg dose gave it each morning between 7 and 9am; compounding-pharmacy protocols commonly move dosing to before bed instead, to align with the nocturnal GH pulse and blunt waking hunger.
Commonly paired with: BPC-157

A 2008 randomized, placebo-controlled trial (Nass et al., Annals of Internal Medicine) gave 65 healthy older adults 25 mg oral MK-677 once daily each morning for up to 2 years continuously, with no cycle-off - GH rose 1.8-fold and fat-free mass increased significantly. That is the dose this page's 25 mg upper bound traces to, but the trial's morning dosing and continuous (uncycled) use contradict common telehealth-prescribed practice, which starts at 12.5 mg and doses at bedtime in 8-12 week courses with a break. Both are kept: the numeric range spans trial and clinic figures, and agreement is marked 'varies' because the timing and cycling advice genuinely conflict.

Plan a cycle in the protocol builder

MK-677 doses used in human studies

A dose-ranging trial in 32 healthy adults aged 64-81 tested oral MK-677 at 2 mg, 10 mg or 25 mg once daily. Each dose ran for two separate periods of 14 and 28 days Chapman 1996 - Chapman IM, Bach MA, Van Cauter E 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;81(12):4249-57., in the references below. The 25 mg dose produced the largest effect. Mean 24-hour growth hormone concentration rose 97% at 2 weeks. Serum IGF-1 rose from 141 to 265 micrograms/L by 4 weeks, into the normal range for young adults.

Two later trials both used the top dose from that comparison, 25 mg once daily, in different populations:

Trial	Population	Dose	Duration
Chapman et al. 1996 Chapman 1996 - Chapman IM, Bach MA, Van Cauter E 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;81(12):4249-57., in the references below	32 healthy adults, aged 64-81	2, 10 or 25 mg/day, oral	Two periods of 14 and 28 days
Svensson et al. 1998 Svensson 1998 - Svensson J, Lönn L, Jansson JO 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;83(2):362-9., in the references below	24 obese men, aged 18-50, BMI >30	25 mg/day, oral	8 weeks
Nass et al. 2008 Nass 2008 - Nass R, Pezzoli SS, Oliveri MC 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;149(9):601-11., in the references below	65 healthy adults, aged 60-81	25 mg/day, oral	2 years (primary endpoints at 1 year)

Not studied: younger, healthy adults training for muscle

MK-677 is marketed heavily to people training for muscle and recovery, but none of the three trials above enrolled that population. The Nass 2008 trial notes fat-free mass increased over 1-2 years in older adults without a corresponding increase in strength or function Nass 2008 - Nass R, Pezzoli SS, Oliveri MC 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;149(9):601-11., in the references below. No published human trial I can cite has tested whether 25 mg/day, or any other dose, does anything different in a younger, healthy, training adult.

Reconstitution and liquid concentration: use the calculator

MK-677 is taken as an oral capsule or liquid, so there is no injection or vial reconstitution step. Working out the concentration of a liquid formulation is a separate question from the dose itself. The dosage calculator does that arithmetic. It does not supply a dose.

What is not established

No FDA-approved dose or label, because MK-677 has never been approved for any indication.
No trial in young, healthy adults training for muscle, the people most vendors target.
No trial ran past 2 years, so no long-term safety data exist past that window.
The common protocol above comes from community and vendor dosing guides, not from any trial cited here. It is current common practice, not a trial finding, even though it lands on the same 25 mg figure.

Who should not use it, and the risks

No FDA-reviewed contraindication list exists for MK-677. These groups were not studied here and should not use it without a clinician directly involved. This is general context from the trials above and from FDA’s own safety flag on the main page:

anyone with a personal or family history of heart failure or cardiac risk factors
anyone with diabetes or impaired glucose tolerance
anyone pregnant or breastfeeding
children

FDA flags a congestive-heart-failure signal from a separate hip-fracture trial. The trials on this page report:

a fasting glucose rise from 5.4 to 6.8 mmol/L by 4 weeks in the dose-ranging trial Chapman 1996 - Chapman IM, Bach MA, Van Cauter E 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;81(12):4249-57., in the references below
reduced insulin sensitivity with a smaller fasting glucose rise in the 2-year trial Nass 2008 - Nass R, Pezzoli SS, Oliveri MC 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;149(9):601-11., in the references below
impaired oral glucose tolerance at 2 and 8 weeks in the obese-male trial Svensson 1998 - Svensson J, Lönn L, Jansson JO 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;83(2):362-9., in the references below
increased appetite, transient lower-leg swelling and muscle pain, a small rise in cortisol, and bone-remodeling changes over 1-2 years Nass 2008 - Nass R, Pezzoli SS, Oliveri MC 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;149(9):601-11., in the references below
reduced total testosterone in the 8-week obese-male trial Svensson 1999 - Svensson J, Carlsson B, Carlsson LM et al. Discrepancy between serum leptin values and total body fat in response to the oral growth hormone secretagogue MK-677. Clin Endocrinol (Oxf). 1999;50(4):451-6., in the references below

No trial measured effects past 2 years.

Side effects in detail, including hair loss: MK-677 side effects.

Where to buy MK-677 (Ibutamoren) for research

Each vendor is checked against my vendor checklist.

I don't list a vendor for MK-677 (Ibutamoren) yet. Before buying from anyone, work through the vendor checklist.

See all vendors and how they compare →

Common questions

What is the usual MK-677 dose?

Community and vendor dosing guides most often describe 12.5-25 mg by mouth once daily, commonly before bed. The cycle is 8-12 weeks with a 4-week break. That is common practice reported by dosing guides. Its upper bound matches the 25 mg the published human trials used. Those trials dosed every morning, continuously with no cycle-off, and tested older adults and obese men, not the younger people most taking MK-677 today. See the next question for the trial detail.

What dose of MK-677 was used in human trials?

25 mg, taken orally, once daily, is the dose used in the three published human trials this page cites. One of them was a dose-ranging trial of 2, 10 and 25 mg once daily. It found 25 mg produced the largest increase in growth hormone and IGF-1.

Is there an FDA-approved MK-677 dose?

No. The FDA has never approved MK-677 (ibutamoren) for any indication, so there is no FDA-reviewed dose or label. The 25 mg figure comes from published human trials, not regulatory approval.

How long were people given MK-677 in these trials?

A dose-ranging trial in older adults ran two separate 14- and 28-day periods. A trial in obese men ran 8 weeks. The longest trial, in healthy adults aged 60 to 81, ran 2 years, with its primary endpoints assessed at 1 year.

Were these trials testing MK-677 for muscle building in young, healthy people?

No. The trials studied healthy older adults (60-81 years old) and obese men (18-50 years old) with blunted growth hormone secretion. They did not study young, healthy people training for muscle gain, who are the people most vendors market MK-677 to. None of the three trials measured muscle strength or athletic performance as an outcome.

How do I work out reconstitution or liquid concentration?

MK-677 is taken as an oral capsule or liquid, not injected, so there is no needle-and-vial reconstitution step. If you are working out the concentration of a liquid formulation, that is separate from the dose itself. Use the dosage calculator for it.

Who should not use MK-677?

No FDA-reviewed contraindication list exists, because no such review has happened. As general context from the trials and FDA safety data on the main MK-677 page, these groups were not studied and should not use it outside a clinician's direct supervision. They are people with a personal or family history of heart failure or cardiac risk factors, and people with diabetes or impaired glucose tolerance (fasting glucose rose in trial participants). They also include anyone pregnant or breastfeeding, and children.

What are the main risks?

FDA's safety listing flags a congestive heart failure signal from a separate hip-fracture trial. The trials on this page report a fasting glucose increase with reduced insulin sensitivity and increased appetite. They also report transient lower-leg swelling and muscle pain, a small rise in cortisol, reduced total testosterone, and bone-remodeling changes. No trial ran long enough to establish long-term safety.

When should I stop and get medical care?

Get emergency care (call 911 in the US) for shortness of breath, rapid swelling, chest pain, or signs of a severe allergic reaction. For a suspected overdose or a reaction that is not an emergency, contact Poison Control at 1-800-222-1222. This page is not a substitute for a clinician who knows your medical history.

References (6 sources)

Bibliographic detail is fetched from PubMed, not written by me - so a citation here cannot drift from the paper it names. Study design comes from PubMed's own tags rather than my judgement.