Peptide basics

MK-677 vs sermorelin: six trials and no approval against an approval and no trials

This page reports registrations, phases, approvals, publications and readership for two compounds. Neither the trial count nor the approval record described below is a statement about hormonal effect, body composition, sleep, or any other outcome.

What this comparison measures

This pair is unusual because the two headline measures disagree. On registered trials MK-677 has the larger record; on regulatory status sermorelin does. Reporting only one of those would produce a confident and wrong summary, so this page reports both and refuses to collapse them into a ranking.¹²⁶

Registered human trials

In the snapshot of 1 August 2026, a registry search under the name ibutamoren returned 8 loose matches, of which 6 were verified as naming the compound an intervention. The same search for sermorelin returned 27 loose matches, of which none were verified.¹²

MK-677's verified studies are mostly phase 2 and span several unrelated questions — a terminated study in patients recovering from hip fracture, a study in Alzheimer's disease, a study in end-stage renal disease, and a more recent study in nonalcoholic fatty liver disease. They do not form a single programme.¹⁴¹⁰

Why sermorelin's registry count is zero

Sermorelin is the 1-29 fragment of growth-hormone-releasing hormone, and registry search engines expand that name into the wider GHRH family. A search therefore surfaces studies of GHRH and of related analogues such as tesamorelin, none of which administer sermorelin under that name.²

This is a limit of name-based counting, and it should be stated rather than hidden. The count reported here is a count of the name in intervention fields. It is not a count of every study that has ever administered GHRH(1-29), and a reader interested in the molecule class rather than the trade name should treat the zero accordingly.²

Regulatory status

Sermorelin acetate is the active ingredient of approved US applications under the brand GEREF, recorded in Drugs@FDA under NDA 019863 and NDA 020443. The openFDA index lists the products under both applications with a marketing status of discontinued.⁶⁷

An approval that has been granted and a product that is currently marketed are different facts. Sermorelin has the first and, in this record, not the second — which is why the site records it as approved while its trial and publication record stays close to empty.⁶⁷

MK-677 has no approved product. Ibutamoren mesylate appears in FDA's category 2 for bulk substances used in compounding under both the 503A policy, added 29 September 2023, and the 503B policy, added 29 December 2022. FDA's stated reason references a randomised trial in patients recovering from hip fracture that was terminated early over a potential safety signal.⁵⁴

Publication trend, 2017 to 2026

A PubMed title/abstract search across 2017 to 2026 returns 22 records for ibutamoren and 17 for sermorelin. Both series sit in low single figures every year, and neither shows a trend that a count this small could support.⁸⁹

MK-677's most-cited human study predates this window: a randomised trial in healthy older adults published in 2008 that measured body composition and clinical outcomes. Nearly every discussion of the compound traces back to it, which is a familiar pattern for compounds whose literature is thin and old.³

MK-677 has six registered studies, a furthest phase of 2, no approved product, and a category-2 listing under both FDA compounding policies.

Sermorelin is the rare case of an approved application with no registered trial record — and its approved products are recorded as discontinued.

Attention against evidence

Between February and July 2026, the ibutamoren Wikipedia article averaged 8,291 views a month with a peak of 10,564; the sermorelin article averaged 8,297 with a peak of 8,819. The two compounds are read at almost the same rate.¹²¹¹

Equal attention across two records that differ this much in shape is the reason this site reports several measures rather than one. A reader who knows only that both are widely read knows nothing about either.¹²

Common questions