What Is MK-677? Dosage, Half-Life & How to Track It
Also known as: Ibutamoren · Ibutamoren Mesylate · Nutrobal
MK-677 is an orally active ghrelin-receptor agonist that raises GH and IGF-1 without an injection. Typical protocols run 10–25 mg once daily, most often 20 mg, taken at a consistent time. Its roughly 24-hour half-life is unusually long for a GH secretagogue — long enough that a single daily oral dose keeps levels elevated around the clock, a fundamentally different exposure pattern than the short, pulsatile GHRPs it is often compared to. Educational information only; MK-677 is not FDA-approved and is not a peptide despite frequently being grouped with them.
What MK-677 is and how it works
MK-677 (ibutamoren) is a small molecule — not a peptide — developed as an oral candidate for growth-hormone deficiency and age-related muscle wasting. Like the injectable GHRPs (ipamorelin, hexarelin, GHRP-2/6), it activates the ghrelin receptor (GHS-R1a) in the pituitary and hypothalamus to trigger GH release. What sets it apart is the route: it survives oral administration and stays active in the blood far longer than a peptide would, which is the entire reason it is swallowed rather than injected.
Because of its ~24-hour half-life, MK-677 does not produce the same discrete daily pulse a subcutaneous GHRP does — instead it keeps GH and IGF-1 modestly and continuously elevated across the day. It was researched for elderly hip-fracture recovery and cachexia; trials showed reliable IGF-1 increases but did not clear the bar for approval, and development for those indications was discontinued.
It never received FDA approval for any use and is not a controlled substance in most jurisdictions the way anabolic steroids are, which has made it widely available online — but availability is not the same as long-term human safety data at typical bodybuilding-community doses, which largely does not exist.
Typical dosing & what a bottle actually gives you
Because MK-677 is orally active, there is no bacteriostatic-water reconstitution step — it ships as capsules or a liquid solution and is measured in mg, not concentration and syringe units the way an injectable peptide is.
- Starting dose: 10 mg once daily
- Common maintenance dose: 20–25 mg once daily
- Most protocols run continuously — MK-677 is not typically pulsed on and off the way GHRPs are
Half-life & what it means for frequency
MK-677’s roughly 24-hour half-life is the single biggest thing separating it from every other GH secretagogue in this library. A short-acting GHRP like ipamorelin clears in about two hours and produces one clean pulse; MK-677 is still substantially present a full day after the last dose, so levels build toward a steady, continuously elevated state rather than a series of discrete spikes.
That is a real trade-off. The always-on exposure is convenient — one pill, once a day, no missed-pulse anxiety — but it is also the mechanistic reason MK-677 is more strongly associated with two dose-limiting side effects, water retention and reduced insulin sensitivity, than the short-pulse peptides are. Constant signaling does not give the body the same off window a natural GH rhythm has.
What to track & common side effects
The most consistently reported effects are increased appetite (often dramatically — this was actually studied for cachexia), water retention or puffiness, and next-day grogginess some describe as an MK-677 hangover. Increased fasting blood glucose and reduced insulin sensitivity show up often enough in longer-running protocols to watch for rather than assume away.
Because it is a once-daily oral with no reconstitution math to get wrong, what is actually worth tracking is behavioral: the daily streak (skipped doses blunt the point of a long-half-life compound), body weight and water trend, and — for anyone running it more than a few months — a fasting glucose check.
How to track MK-677 in Frontload
Log the daily dose and let the streak keep a once-a-day pill from quietly turning into "most days" — MK-677’s whole value proposition depends on consistent daily dosing. Track weight, since water retention shows up fast, and if you are running it long-term, keep fasting glucose in view as the side effect most worth catching early.
Model it yourself · free, no account
Blood-Level Simulator
Model it yourself: pick MK-677, set your daily dose, and watch how a 24-hour half-life builds toward a steady, continuously elevated level — a completely different curve than a short-pulse GHRP — the same pharmacokinetic engine that runs inside the app.
Related compounds
Related reading: Peptide reconstitution math: how much BAC water to add
Frequently asked questions
What is MK-677 used for?
MK-677 (ibutamoren) is an orally active ghrelin-receptor agonist studied for raising growth hormone and IGF-1 — originally researched for elderly muscle wasting and hip-fracture recovery. It is not FDA-approved for any use and is not a peptide, despite often being grouped with GH peptides.
What is the half-life of MK-677?
Roughly 24 hours — unusually long for a GH secretagogue. That is what allows a single daily oral dose to keep GH and IGF-1 continuously elevated, rather than producing the short discrete pulse a subcutaneous GHRP does.
How much MK-677 should you take?
Typical protocols start around 10 mg once daily and move to a 20–25 mg maintenance dose, usually at a consistent time such as before bed. It is dosed continuously rather than cycled on and off the way some GHRPs are.
Does MK-677 cause water retention?
Yes — it is one of the more commonly reported side effects, along with increased appetite and reduced insulin sensitivity at higher or longer-running doses. These trace to MK-677’s continuous, rather than pulsed, elevation of GH.
This is educational information, not medical advice. Doses and protocols above reflect published references and community practice — protocol decisions belong with your prescribing physician. Generic names used throughout. How this reference is built & how the AI is tested →
FRONTLOAD
Track it instead of guessing.
Doses, reconstitution, bloodwork, and an AI coach grounded in your own data. Free to start, on the App Store and Google Play.