Tesamorelin
A stabilised GHRH(1-44) analogue — the most clinically characterised secretagogue here.
Growth hormone axis · 7 min read · updated 13 Aug 2026
Research use only. The ranges below are what published studies and community protocols report. They are reference material for laboratory research, not medical advice or a recommendation for human or veterinary use.
The compound
Tesamorelin
View- Type
- GHRH Analog
- CAS
- 218949-48-5
- Formula
- C₂₂₁H₃₆₆N₇₂O₆₇S
- Mass
- 5135.9 Da
At a glance
- Class
- GHRH analogue
- Structure
- Human GHRH(1-44) with an N-terminal trans-3-hexenoyl group
- Molecular weight
- 5135.9 Da
- CAS
- 218949-48-5
- Regulatory status
- Approved for HIV-associated lipodystrophy
- Vial sizes stocked
- 2 mg, 10 mg
Tesamorelin is full-length human GHRH — all 44 residues, not the truncated 1-29 fragment — with a hexenoyl group attached to the N-terminus. That modification blocks DPP-4 cleavage at the vulnerable N-terminal position, giving the molecule enough plasma stability to be practical while keeping the native receptor interaction intact.
It is the only secretagogue in this section with a full approval and a mature trial dataset. The registration studies targeted visceral adipose tissue in HIV-associated lipodystrophy, where 2 mg daily reduced visceral fat by roughly 15% over 26 weeks (about 18% by 52 weeks in the extension), with the effect reversing on withdrawal. The visceral-selectivity is the striking part: subcutaneous fat was largely unchanged.
Because it acts at the GHRH receptor on the pituitary, GH release remains pulsatile and feedback-regulated, in the same way as the CJC/ipamorelin combination — but with far better characterised pharmacology behind it.
Why visceral fat specifically
Visceral adipose tissue is more lipolytically responsive to GH than subcutaneous adipose, carrying higher GH-receptor density and greater hormone-sensitive lipase activity. Raising pulsatile GH therefore acts disproportionately on the visceral depot. It is one of the cleaner examples of a systemic hormone producing a compartment-selective effect.
Beyond lipodystrophy
- NAFLD / hepatic steatosis — a randomised trial reported reduced hepatic fat fraction over 12 months, consistent with the visceral-depot mechanism.
- Cognition — a study in older adults with mild cognitive impairment used 1 mg daily over 20 weeks and reported executive-function changes. Small, and not replicated at scale.
- IGF-1 dynamics — tesamorelin raises IGF-1 into the upper physiological range at 2 mg daily, which is the exposure marker used across the trials.
How it differs from the CJC/ipamorelin pairing
- One receptor, not two. There is no ghrelin-receptor arm, so no somatostatin suppression and no appetite or flushing component.
- Both are short-acting at the GHRH receptor — tesamorelin's subcutaneous plasma half-life is only about 8–11 minutes — so once-daily dosing reflects the regimen the trials established, not a longer duration of action than no-DAC CJC-1295.
- A real clinical dataset with defined endpoints, defined dose and defined duration — the reason its protocol table is short and specific rather than a range.
Storage
- Lyophilised: 2–8 °C, or −20 °C for extended storage.
- Reconstituted: 2–8 °C, used within about 28 days, protected from light. Never freeze.
- The room-temperature storage sometimes quoted for reconstituted tesamorelin comes from the EGRIFTA WR label — a cyclodextrin-stabilised commercial formulation whose label permits 20–25 °C for at most 7 days and explicitly says not to refrigerate it. That claim belongs to that formulation, not to a generic lyophilisate in bacteriostatic water: keep research material refrigerated.
- A 10 mg vial reconstituted for daily 2 mg dosing runs out in five days — well inside the stability window. A 1 mg daily protocol takes ten days. Either is comfortable.
Cautions
- Injection-site erythema and pruritus are the most common reported effects.
- Glucose tolerance can deteriorate, as with any sustained increase in GH exposure. This was monitored throughout the registration trials.
- Arthralgia, peripheral oedema and paraesthesia occur and are dose-related — the standard GH-axis pattern.
- IGF-1 rises into the upper physiological range at 2 mg daily; exposure above that has not been characterised.
References & credit
- 1Falutz J et al., NEJM 2007 — Registration trial — tesamorelin and visceral adipose tissue in HIV-associated lipodystrophy.
- 2Stanley TL et al., JAMA 2014 / Lancet HIV 2019 — Hepatic fat fraction endpoints.
- 3Baker LD et al., Archives of Neurology 2012 — GHRH administration and cognition in mild cognitive impairment — the 1 mg protocol.
This article was written in-house. Where a dose range reflects community practice rather than a published trial, the community references we consulted are credited above and the article says which is which.