MK-677 / Ibutamoren half-life and steady state
24 h modelled half-life, peaking 1 h after a dose. What that means for how long it lasts, how much it builds up, and when bloodwork is worth drawing.
- Also known as
- Nutrobal
- Class
- GH Secretagogues
- Modelled half-life
- 24 h
- Time to peak
- 1 h
- Formulation
- Oral
- Cleared per dosing interval
- 50% gone, 50% still present after 24 h
- Time to steady state
- ~5 days (about five half-lives)
- Accumulation at that cadence
- 2× a single dose
- Peak-to-trough at steady state
- 1.94×
- Regulatory status
- Research
- Monitoring panel
- IGF-1 every 6–8 weeks, fasting glucose, HbA1c, prolactin, cortisol, lipid panel. Baseline before starting.
- Storage
- Room temperature and dry, in the original container with whatever desiccant came in it, out of light.
- Once opened
- Unchanged once opened, as long as it stays dry.
- What ruins it
- Humidity is the real enemy — a bathroom cabinet is the worst place in the house for these.
- Handling caveat
- General handling practice for this formulation. Your supplier’s own insert or COA overrides anything here.
MK-677 is the odd one out in this set, and its twenty-four-hour half-life is why. Every other growth hormone secretagogue here is an injected peptide cleared in minutes to hours, dosed for a pulse. MK-677 is an orally active non-peptide with a day-long half-life, so a daily dose produces continuous elevation of growth hormone signalling rather than a pulse. That is a genuinely different pharmacology wearing the same category label.
The arithmetic: a twenty-four-hour interval against a twenty-four-hour half-life means each dose lands on half the last, so the level roughly doubles and plateaus after about five days. Unlike the peptides, MK-677 therefore has a real steady state, and the curve below shows it building. That is also the source of most of what people report from it — the appetite effect, the water retention, the sleep changes — because a continuously elevated signal produces continuous effects, not a nightly pulse.
Continuous is the thing to weigh rather than a detail. Sustained growth hormone and IGF-1 signalling has metabolic consequences: fasting glucose and HbA1c commonly drift upward, and insulin sensitivity can fall. That is why the monitoring panel the app records for MK-677 is the longest of any compound on this page — IGF-1, fasting glucose, HbA1c, prolactin, cortisol and a lipid panel, with a baseline before starting. It is not an approved medicine, it never completed development for any indication, and it is banned in competitive sport. The pharmacokinetics are the clearest thing about it; the risk-benefit is not.
One dose
pkCurve function — a
one-compartment absorption-and-elimination model with the absorption rate fitted so the
peak lands at the published time to peak.Dosed once daily
Charted at once daily because that is the once-daily bedtime schedule in the app's own dosing rows. It is what the numbers below are indexed to, not a recommendation about frequency — that is a prescribing decision.
The arithmetic behind those numbers
fraction left after one interval = 2^(−1.00) = 0.500
accumulation ratio = 1 ÷ (1 − 0.500) = 2
time to steady state ≈ 5 × half-life = 5 days
peak-to-trough = simulated, 2.007 ÷ 1.0348 = 1.94
The accumulation ratio is a closed form; the peak-to-trough figure is not. The generator adds up enough repeated curves for the total to stop changing, then reads the highest and lowest points of the last interval — which is what steady state means in practice. The vertical axis is relative, not a concentration: the shape and the ratios carry across people, the absolute levels do not.
The dosing rows this cadence came from
Off-label or community practice Reproduced from the app's entry so you can see what the chart above is indexed to. Which row applies to a particular person, if any, is a clinical decision this page does not make.
| Label | Amount | Route and frequency |
|---|---|---|
| Starting | 10mg/day | Oral at bedtime |
| Standard | 15–25mg/day | Oral at bedtime |
When to draw bloodwork
The panel the app records for MK-677 / Ibutamoren is: IGF-1 every 6–8 weeks, fasting glucose, HbA1c, prolactin, cortisol, lipid panel. Baseline before starting.. The pharmacokinetic point is the timing rather than the list: after any change, a level takes about 5 days to settle, so a panel drawn sooner measures something still moving. And because the peak-to-trough swing here is 1.94×, when in the interval you draw changes the result materially — a result without a stated draw time relative to the last dose is hard to compare with anything. Whether a result means anything is a question for the clinician who ordered it, read against the reference range your own lab printed. The lab-marker pages cover what the individual analytes measure.
Related: the interactive half-life calculator to try other cadences.
The app draws this curve from the doses you actually logged — your dates, your cadence — and projects seven days forward from the last one.
Save this dose to your log