Skip to content
Tesamorelin.app

Mechanism Explorer

Tesamorelin mechanism of action

Tesamorelin acts one step upstream of growth hormone. It stimulates the pituitary's own GH release through the GHRH receptor; it is not growth hormone itself[1]. Step through the pathway below. Each step cites its source.

By Tesamorelin.app editorial teamSources reviewed How we source

Tesamorelin signalling pathwayTesamorelin binds the growth hormone-releasing hormone receptor on a pituitary somatotroph cell. The receptor is coupled to G proteins that activate adenylyl cyclase, leading to growth hormone synthesis and pulsatile release. Growth hormone then raises circulating IGF-1 and IGFBP-3. The ghrelin receptor, a different receptor, is shown for contrast.TesamorelinGHRH(1–44) analoguePituitary somatotroph cellGHRHRAdenylyl cyclaseactivated via G proteinsGH synthesis & releasepulsatileIGF-1 and IGFBP-3 risemeasured in circulationTSH, LH,ACTH, PRLno clin. changeGhrelin receptor (GHSR)a different receptor;target of ipamorelin
Schematic, not to scale. Only relationships stated in the cited sources are drawn.

Step 1 of 7

Why “upstream” matters

Tesamorelin works through the GHRH receptor, so the growth hormone it produces comes from the pituitary itself and is released in pulses[1,4]. Measured effects such as the rise in IGF-1 follow from that pituitary response[1].

A different receptor from ghrelin mimetics

Some other peptides that raise growth hormone act on a separate receptor, the growth hormone secretagogue receptor (GHSR, also called the ghrelin receptor). That receptor is coupled to G(q) and also binds other GH-releasing peptides[5]. Ipamorelin is one such compound[6]. See tesamorelin vs ipamorelin.

References

  1. 1.EGRIFTA WR (tesamorelin) for injection, Prescribing Information. Revised 03/2025; DailyMed SPL version 2 (published 2026-08-03). DailyMed · accessed 2026-11-11
  2. 2.UniProtKB P01286. Somatoliberin (GHRH), Homo sapiens. UniProt · accessed 2026-11-11
  3. 3.UniProtKB Q02643. Growth hormone-releasing hormone receptor (GHRHR), Homo sapiens. UniProt · accessed 2026-11-11
  4. 4.Stanley TL, et al. Effects of a growth hormone-releasing hormone analog on endogenous GH pulsatility and insulin sensitivity in healthy men. J Clin Endocrinol Metab. 2011;96:150-8. PubMed · PMID 20943777 · doi:10.1210/jc.2010-1587 · accessed 2026-11-11
  5. 5.UniProtKB Q92847. Growth hormone secretagogue receptor type 1 (GHSR), Homo sapiens. UniProt · accessed 2026-11-11
  6. 6.Raun K, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139:552-61. PubMed · PMID 9849822 · doi:10.1530/eje.0.1390552 · accessed 2026-11-11