Independent reference & toolkit 100 compounds graded · Last reviewed June 2026

Compare · GH secretagogue

GHRP-6 vs MK-677

Both are gh secretagogue compounds. Here's how they line up on the evidence — graded the same way.

GHRP-6MK-677
Evidence 6/10 7/10
ClassGH secretagogueGH secretagogue
SummaryAn old growth-hormone-releasing peptide that reliably raises GH and appetite in humans, but whose marketed muscle, fat-loss, and disease claims lack solid trials.MK-677 reliably raises growth hormone and IGF-1, but disease trials failed and one was stopped for a heart-failure signal. Investigational, never approved.
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GHRP-6

GHRP-6 is one of the oldest lab-made peptides designed to nudge the body into releasing growth hormone. The basics of what it does in people are genuinely well understood: it raises growth hormone (GH, a hormone that helps the body grow and repair tissue), and it makes people hungry. What is…

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MK-677

MK-677, also called ibutamoren, is one of the odder entries you'll find in any peptide reference — because it isn't actually a peptide. It's a man-made molecule that tricks the body into releasing more of its own growth hormone. And unlike most of the products sold to the fitness and "anti-aging"…

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