MK-677 half-life
MK-677 (ibutamoren) is an orally active growth hormone secretagogue, a non-peptide taken by mouth rather than injected. Its terminal half-life in humans is roughly 24 hours, so the blood level falls by about half over the course of a day, which is what makes once-daily dosing workable. Because each dose only partly clears before the next, a steady once-a-day schedule builds up to a stable level over the first several days.
What a half-life actually means
A half-life is the time it takes for half of what is in your blood to be gone. It does not mean the compound is finished at that point. Half goes, then half of what is left goes, and so on.
That is why the last traces take so much longer to disappear than the first. Most references treat something as effectively cleared after about five half-lives, which for MK-677 is roughly 5 days.
How MK-677 clears
| Half-lives | Time since dose | Roughly left |
|---|---|---|
| 1 | 24 hours | 50% |
| 2 | 2 days | 25% |
| 3 | 3 days | 12.5% |
| 4 | 4 days | 6.25% |
| 5 | 5 days | 3.125% |
These are round numbers from a single half-life figure. Real clearance shifts with dose, body composition, liver and kidney function, and what else you are taking. Treat it as a shape, not a schedule.
Why the timing matters
A short half-life means levels swing between doses, so timing and frequency do most of the work. A long half-life means levels build for days or weeks before they settle, so a change you make today might not show up for a while, and stopping does not clear things straight away.
MK-677 sits at about 24 hours, so it behaves like the medium end of that range.
See your own levels, not a table
NextDose models your actual blood level from the doses you log, then calibrates the curve to your bloodwork. Built on 30,000+ research papers, clinical trials and FDA records.
Get NextDose.AIWhen levels level off
On a repeating schedule the amount in your body climbs until what you take in each interval matches what clears in it. That plateau is called steady state, and it arrives after roughly five half-lives whatever the dose. For MK-677 that is about 5 days of consistent dosing.
The typical starting schedule is 1x daily before bed, at 10 mg/day. Until that plateau, every dose lands on top of more of the last one than it will later, which is why the first weeks of a protocol can feel different from the same dose a month in.
Skipping doses resets part of that climb. One missed dose costs roughly one half-life of accumulation, so the shorter the half-life the more a gap matters.
Mixing and measuring MK-677
Oral capsule or liquid — no reconstitution
Store at 15-25°C (room temp). 2 years sealed, 6 months opened.
Research mentioning MK-677
Indexed records from PubMed and ClinicalTrials.gov that reference MK-677. These are here so you can read the primary material yourself. They are not the source of the half-life figure above.