Claimed effect · MK-677 (ibutamoren)

Does MK-677 (ibutamoren) help with growth hormone / IGF-1 elevation?

A
Grade A — established in humansMultiple RCTs · effect size: large
Short answerEstablished in humans. Multiple RCTs point the same way: a large effect. Oral daily dosing reliably restores growth hormone and IGF-1 in older adults to the levels of healthy young adults, and raised IGF-1 by 60–73% in a 563-person trial. This effect is not in dispute.

What the studies show

Oral daily dosing reliably restores growth hormone and IGF-1 in older adults to the levels of healthy young adults, and raised IGF-1 by 60–73% in a 563-person trial. This effect is not in dispute.

“Daily administration of MK-677 significantly increased growth hormone and insulin-like growth factor I levels to those of healthy young adults without serious adverse effects.”

Verbatim, from the abstractNass 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):601–611

Several well-run randomised trials in people, pointing the same way. You can plan around this. It still says nothing about whether the effect is worth the side effects for you.

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In context

MK-677 is a small molecule, not a peptide, that mimics the hunger hormone ghrelin and raises growth hormone and IGF-1 when taken by mouth. Unusually for a grey-market compound, it has been through proper trials. In 65 healthy older adults over a year it raised fat-free mass by about 1.1 kg against a 0.5 kg loss on placebo, with no change in total or visceral fat. In 563 people with Alzheimer's disease it raised IGF-1 by 73% and did nothing for the disease. It has never been approved anywhere and is prohibited in sport.

MK-677 (ibutamoren) is not approved. Legal status differs by country — see the regulation section or the jurisdiction pages.

Questions

Is MK-677 (ibutamoren) proven to help with growth hormone / IGF-1 elevation?
Yes, as far as human trials can show it: Multiple RCTs. LYO grades this outcome A.
What studies are behind the grade?
Oral daily dosing reliably restores growth hormone and IGF-1 in older adults to the levels of healthy young adults, and raised IGF-1 by 60–73% in a 563-person trial. This effect is not in dispute.
Is MK-677 (ibutamoren) approved for this?
No. MK-677 (ibutamoren) is not approved; it is not an approved medicine for any indication in the jurisdictions LYO covers.

Other outcomes for MK-677 (ibutamoren)

Written and maintained by LYO Research — how pages are written and checked. Reviewed 10 September 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →