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

Compare · GH secretagogue

MK-677 vs Sermorelin

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

MK-677Sermorelin
Evidence 7/10 8/10
ClassGH secretagogueGH secretagogue
SummaryMK-677 reliably raises growth hormone and IGF-1, but disease trials failed and one was stopped for a heart-failure signal. Investigational, never approved.Sermorelin is a synthetic GHRH fragment that nudges the pituitary to release growth hormone; human data is old and thin, with no modern anti-aging RCTs.
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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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Sermorelin

Sermorelin is one of the oldest peptides in the "growth hormone" group, and unlike most of its cousins it actually held FDA approval at one point. People often lean on that history to suggest it does more than the evidence really backs up.

Read the full evidence-graded Sermorelin profile →

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