Sermorelin vs Tesamorelin

How Sermorelin and Tesamorelin differ

Sermorelin and Tesamorelin are different molecules derived from the same parent, human growth hormone-releasing hormone (GHRH), a 44-residue hypothalamic hormone. Sermorelin is the N-terminal 29-residue fragment of that hormone, and the names GRF(1-29) and GHRH(1-29) both refer to it. Tesamorelin is an analog of the full 44-residue hormone, carrying a trans-3-hexenoyl group on its N-terminus. Sermorelin carries no such group; its N-terminus is free. Both act at the pituitary GHRH receptor.

In the literature reviewed for Sermorelin, the most widely known "GHRH" findings are not Sermorelin findings. One such human trial used Tesamorelin, and its abstract names that compound.^[7] Nothing from that Tesamorelin literature transfers to Sermorelin. Other human "GHRH" trials in the literature reviewed for Sermorelin used a different molecule, a norleucine-substituted analog.^[9][10] On the evidence available, those trials do not apply to Sermorelin either. In an August 2026 PubMed search, most of the 331 records naming Sermorelin used it as a diagnostic reagent rather than as the compound under study.^[11] The literature reviewed for Sermorelin reports no human safety data from studies in adults.

In the literature reviewed for Tesamorelin, its two phase 3 trials used imaging surrogates as primary endpoints, not clinical outcomes. Those two papers and the pooled analysis of both were manufacturer-sponsored, with sponsor-affiliated co-authors. In the first of the two randomized placebo-controlled phase 3 trials, withdrawal because of an adverse event was higher on Tesamorelin than on placebo.^[12]

The trial registry adds to the confusion. Some records returned by a Sermorelin search name the intervention only as GHRH.^[8] At least two completed records in that search name Tesamorelin, directly or by its development code.^[8]

Saying sermorelin acetate is FDA approved is false, and saying it was never FDA approved is equally false. It held two US approvals, each for one indication: a diagnostic one in 1990 and a therapeutic one in 1997.^[1][2] Both were withdrawn at the sponsor's request, as of June 2009.^[1][2] The FDA approved tesamorelin acetate in 2010 for one therapeutic indication.^[4][5] That approval is current, and it belongs to tesamorelin acetate and that one indication. The sermorelin acetate record likewise belongs to that molecule alone, so neither record extends to the other. Both compounds, as supplied for research, are bulk material rather than finished medicines. Sermorelin acetate was the active ingredient of prescription medicines, since withdrawn; tesamorelin acetate is the active ingredient of a prescription medicine sold under another name. Neither material supplied here is one of those medicines: each is a research-grade preparation and holds no marketing authorization. The label of the medicine containing tesamorelin acetate lists glucose intolerance or new diabetes among its warnings; HbA1c reached 6.5% or above in 5% of participants on the drug against 1% on placebo.^[13]

Have Sermorelin and Tesamorelin been compared directly?

No direct comparison of Sermorelin with Tesamorelin was found in a PubMed search run in October 2026.^[6] That search covers PubMed only.