MK-677 (Ibutamoren): what it is and what the evidence says
An oral secretagogue studied for its relationship with sustained growth-hormone and IGF-1 signaling. It is a small non-peptide molecule that activates the ghrelin receptor, which amplifies your own GH pulses and keeps IGF-1 elevated.
Last reviewed: August 16, 2026 · How we verify this
The ground it plays on
Hormones work in axes: a signal from the brain tells a gland to release another hormone, and so on down the chain, with brakes that shut the process off. Intervening at one point has consequences both upstream and downstream. That is why this is the group where professional assessment stops being a recommendation and becomes essential.
What it is studied for
Recovery, appetite, sleep, composition.
There is a distinction that almost always gets lost. A compound being studied for something is not the same as achieving it. And even where it works in a dish or in a mouse, that says little about whether it works in a person or whether the benefit is worth the risk. The section below therefore carries more weight than everything above it.
What the human evidence says
It is the compound in its group with the most randomized trials. It raises GH and IGF-1 in a sustained way and increased lean mass in older adults, with no change in strength. In hip fracture and in Alzheimer's disease it did not change clinical outcomes; in children with GH deficiency, phase 2 (LUM-201) met its endpoints and phase 3 began in 2026.
The limitation that matters most
It remains to be shown whether the lean mass gained translates into strength and function, and there are no trials yet in young adults who train. Long-term safety for glucose and the heart is still being studied. In the trials fasting glucose rose and insulin sensitivity fell, and one hip fracture study was stopped over cases of heart failure. There is also one published case of elevated liver enzymes.
Regulatory status
Not approved by any agency. In the United States it is an investigational drug (LUM-201, in a pediatric phase 3 trial since 2026); the FDA keeps it in Category 2 of bulk substances for compounding, and its advisory committee voted in 2024 against adding it to the 503A list. Banned in sport at all times by WADA (section S2), which lists it by name.
Status can change and varies by country. Always verify the rules in force where you live before drawing conclusions.
Cautions and context
May affect fluid retention, appetite and insulin sensitivity; monitoring matters. Fasting glucose, HbA1c, blood pressure, ankle swelling, and liver enzymes are the checks that go along with it.
With prediabetes, diabetes, high blood pressure, heart disease, or a history of cancer, have a professional assess it before you start and follow it with lab work while you are on it.
What this page cannot give you
A reference page can take you this far. You know what MK-677 (Ibutamoren) is and where its research stands, which already puts you ahead of most readers. Four questions remain that no encyclopedia can answer for you, because the answers depend on your own situation:
- What would you measure beforehand, so that later you could tell whether anything actually changed?
- What would you watch along the way, and how consistently?
- What would you ask a professional, and in how much detail, so you do not walk out with a textbook answer?
- What would make you stop?
That is what the course is for
PeptiXtreme is ${CIF.LECCIONES} lessons that hand out no numbers. Each one ends with your starting point, what to watch along the way, the specific questions you take to a professional and the signals that mean stop. It includes per-module exams, a Certificate of Completion with a verifiable certificate ID, a Progress Tracker to follow how you are doing, and a human advisor you can actually write to.
See the course → Or measure your judgment, freeReferences
Every entry links to its record on PubMed, the US National Library of Medicine database. Open them and check. We would rather have a reader who verifies than one who takes our word for it.
- Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults: a randomized trialhuman Ann Intern Med · 2008 · PMID 18981485 →
- MK-677, an orally active growth hormone secretagogue, reverses diet-induced catabolismhuman J Clin Endocrinol Metab · 1998 · PMID 9467534 →
- Effects of oral administration of ibutamoren mesylate, a nonpeptide growth hormone secretagogue, on the growth hormone-insulin-like growth factor I axis in growth hormone-deficient childrenhuman Clin Pharmacol Ther · 2001 · PMID 11452249 →
- Growth hormone secretagogue MK-677: no clinical effect on AD progression in a randomized trialhuman Neurology · 2008 · PMID 19015485 →
- MK-0677 (ibutamoren mesylate) for the treatment of patients recovering from hip fracture: a multicenter, randomized, placebo-controlled phase IIb studyhuman Arch Gerontol Geriatr · 2011 · PMID 21067829 →
- The Safety and Efficacy of Growth Hormone Secretagoguesreview Sex Med Rev · 2018 · PMID 28400207 →
- Hepatotoxicity induced by MK-677human BMJ Case Rep · 2025 · PMID 40675653 →
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Frequently asked questions
What is MK-677 (Ibutamoren)?
An oral secretagogue studied for its relationship with sustained growth-hormone and IGF-1 signaling. It is a small non-peptide molecule that activates the ghrelin receptor, which amplifies your own GH pulses and keeps IGF-1 elevated. It is studied within the area of hormonal/sexual.
Is there human evidence for MK-677 (Ibutamoren)?
It is the compound in its group with the most randomized trials. It raises GH and IGF-1 in a sustained way and increased lean mass in older adults, with no change in strength. In hip fracture and in Alzheimer's disease it did not change clinical outcomes; in children with GH deficiency, phase 2 (LUM-201) met its endpoints and phase 3 began in 2026.
Is it approved by any health agency?
Not approved by any agency. In the United States it is an investigational drug (LUM-201, in a pediatric phase 3 trial since 2026); the FDA keeps it in Category 2 of bulk substances for compounding, and its advisory committee voted in 2024 against adding it to the 503A list. Banned in sport at all times by WADA (section S2), which lists it by name.
What is the dose of MK-677 (Ibutamoren)?
We do not publish dosages. This is not an oversight. No single figure works for everyone: the regimen depends on a person's medical history, on whatever medication they already take, and on the goal they are chasing, which is something a professional weighs with the case in front of them. What you can build is the ability to walk into that appointment knowing what to ask.
Where can I learn to evaluate this properly?
This page tells you what MK-677 (Ibutamoren) is and what the evidence says. The PeptiXtreme course teaches the other half: what you would measure before considering anything, what you would watch, the specific questions you would take to a professional and when you would stop.