Research context · 2 mg s.c. once daily
Doses of Tesamorelin Studied in the Trials
What was administered, to whom, by which route, and for how long — the research record on dose, half-life, and stability. No human dosing instructions.
The short version
Across the studies, tesamorelin was given as a 2 mg shot under the skin once a day — that single regimen carried almost all of the evidence, including FDA approval [1][7]. A few studies tested a smaller 1 mg dose. The peptide clears the blood fast (within roughly half an hour), but the growth-hormone signal it sets off lasts long enough that once a day was enough [16]. This page describes what researchers measured in their trials. It is not a dosing guide, and tesamorelin dosage outside the approved HIV use has not been established in large studies.
Doses studied in the tesamorelin trials
The dominant regimen across the entire literature is 2 mg subcutaneously once daily. It was the dose used in both pivotal Phase 3 trials and is the FDA-approved regimen [1][2]. The 412-patient NEJM trial, the 52-week program, the pooled 806-patient analysis, and the JAMA hepatic-fat trial all administered 2 mg/day [1][2][7][3]. That consistency is part of why the dose is well characterized: nearly every efficacy and safety figure summarized on this site comes from the same 2 mg once-daily exposure, which makes the results directly comparable across studies.
A 1 mg subcutaneous once-daily arm has appeared in narrower studies — including a cognition trial in older adults and as a lower arm in a type-2-diabetes safety trial — but the extensively characterized paradigm is the once-daily 2 mg dose [4]. A later, higher-concentration once-daily reformulation also exists; the 2 mg once-daily paradigm remains the one supported by the bulk of the trial evidence. No trial in the corpus tested a substantially higher dose in pursuit of a larger effect, so the dose-response curve above 2 mg is not characterized in the published record.
Duration and the populations studied
Treatment duration in the registration program ran to 26 weeks for the primary visceral-fat endpoint, extended to 52 weeks in the long-term phase [1][2]. The JAMA hepatic-fat trial ran for 6 months [3], the healthy-men mechanistic study for 2 weeks [4], and the 2026 meta-analysis pooled five RCTs of varying length [13]. Across these durations the visceral-fat effect appeared by the 26-week assessment and held through a year of continued dosing [2].
The population matters as much as the schedule. Every pivotal efficacy trial enrolled HIV-positive adults on antiretroviral therapy with abdominal fat accumulation [1][2][7]; the only non-HIV human exposures in the corpus are the mechanistic healthy-men study [4] and a cognition trial in older adults. Read that way, the dose record is a record of what was given to a specific patient group — not a general-population dosing guide.
Route studied
Only one route appears in the clinical record: subcutaneous injection at an abdominal site [1]. It is the only route studied in the trials and the only FDA-approved route. There is no published clinical evidence for oral, intranasal, or other delivery of tesamorelin — the molecule is a 5,135.9-Da peptide, and oral peptides of that size are not absorbed intact, which is consistent with the injectable-only record. The abdominal subcutaneous site is also where the visceral-fat endpoint was measured, though the injection's effect is systemic rather than local: the drug acts on the pituitary, not on the fat beneath the needle [4].
Half-life and the sustained IGF-1 effect
Population pharmacokinetic modeling reported an apparent plasma clearance of approximately 1,060 L/h, with no clinically relevant demographic covariates and a roughly 13% increase in absorbed fraction by day 14 versus day 1 [16]. Secondary sources (the FDA label and Mayo Clinic) describe a terminal half-life on the order of 26 to 38 minutes.
The pharmacology that matters is the gap between molecule and effect. The peptide clears in minutes, but the IGF-1 elevation it triggers persists across a once-daily dosing interval — the basis for the once-daily schedule used in every trial [16]. This is why a fast-clearing peptide can still drive a sustained, day-long hormonal signal.
Stability and formulation notes
The trans-3-hexenoic acid N-terminal modification is what gives the molecule its usable shelf life in the body: it blocks the DPP-IV cleavage that inactivates native GHRH within minutes [8]. Pharmaceutically, tesamorelin is supplied as a lyophilized (freeze-dried) powder that requires reconstitution before injection; the FDA label specifies refrigerated storage and use of the reconstituted solution within a defined window. Research-grade material sold for laboratory use lacks the purity and potency oversight of the approved product, a point flagged across recent peptide reviews [15].