AOD-9604 vs Tesamorelin
AOD-9604 is a synthetic hexadecapeptide corresponding to the C-terminal lipolytic domain of human growth hormone, developed on the premise that fat-metabolism effects could be separated from growth hormone receptor signalling and IGF-1 elevation. Tesamorelin is a synthetic growth hormone-releasing hormone analogue that works in the opposite direction, deliberately raising endogenous pulsatile growth hormone and therefore IGF-1, and it holds approval for HIV-associated lipodystrophy on the strength of large randomised trials with visceral adipose tissue as the primary endpoint. They are compared because both are marketed around fat loss and both derive from growth hormone biology. No study has administered them together or in parallel arms, and the two evidence bases differ so sharply in design that the comparison is closer to a contrast in regulatory history than a comparison of effects.
No study has compared them directly.
Everything below is drawn from separate studies that used different models, endpoints and species. That is a real limit on what can be concluded, not a formality.
No published study has given AOD-9604 and tesamorelin to the same subjects or compared them in parallel arms, in any species or model. Searches of PubMed and Europe PMC returned only narrative reviews in which both compounds appear in separate sections: a sports-medicine review of approved and unapproved peptide therapies, an orthopaedic peptides review, and an endocrinology review of GH-IGF1 axis peptides used outside regulated indications. Reviews that list two compounds do not compare them experimentally. Any comparison is therefore indirect and drawn from literatures that differ fundamentally in kind: tesamorelin has multicentre randomised placebo-controlled trials with imaging-based primary endpoints and two independent 2026 meta-analyses, whereas AOD-9604 has no standalone peer-reviewed efficacy trial at all, its human record consisting of a pooled safety and tolerability analysis. The nearest thing to a comparison inside the AOD-9604 literature is a chronic rodent study that ran intact human growth hormone alongside the fragment, reporting that both reduced body-weight gain and increased fat oxidation in obese mice while the fragment did not bind the growth hormone receptor.
Side by side.
| AOD-9604 | Tesamorelin | |
|---|---|---|
| Evidence maturity | Early clinical | Approved drug |
| Studies cited here | 17 | 15 |
| Published 2023 or later | 4 | 11 |
| Newest paper | 2026 | 2026 |
| Molecular class and origin | A synthetic 16-amino-acid peptide corresponding to the C-terminal domain of human growth hormone, Tyr-hGH 177-191, commonly written as hGH fragment 176-191. It is a fragment of a hormone rather than an analogue of a releasing factor. | A synthetic 44-amino-acid analogue of growth hormone-releasing hormone, acting at the GHRH receptor on the anterior pituitary to stimulate endogenous, pulsatile growth hormone secretion. |
| Relationship to the GH axis | Designed to sit outside it. Binding experiments in the preclinical literature indicated no interaction with the growth hormone receptor, and the pooled human safety analysis reported no effect on serum IGF-1 and no negative effect on carbohydrate metabolism on oral glucose tolerance testing. | Designed to drive it. IGF-1 elevation is an expected consequence, and glucose homeostasis, arthralgia and IGF-1 elevation are recorded as safety signals in the research entry. |
| Regulatory status | No approved therapeutic formulation. The 2014 non-clinical package of genotoxicity and chronic toxicology studies was assembled to support a food-ingredient position rather than a drug indication, and later analytical work identified the peptide in seized, unlabelled preparations. | An approved drug for HIV-associated lipodystrophy, supported by multicentre phase 3 trials and included in anti-doping screening methods as a prohibited GHRH analogue. |
| Human efficacy evidence | None published as a standalone peer-reviewed report. Human obesity trials were conducted, but only their pooled safety and tolerability data appeared in the literature; body-composition outcomes have not been independently replicated in an indexed journal. | Randomised placebo-controlled trials with imaging endpoints. In a 412-participant trial visceral adipose tissue fell 15.2% with tesamorelin and rose 5.0% with placebo, and in a 61-participant NAFLD trial hepatic fat fraction fell by an absolute 4.1% with 35% of recipients reaching a fraction below 5% versus 4% on placebo. |
| Meta-analytic position | No meta-analysis of efficacy exists, because no eligible randomised efficacy reports exist to pool. | Two 2026 meta-analyses. One pooled four randomised trials and 909 participants, reporting reductions in visceral adipose tissue and waist circumference and an increase in lean body mass, alongside higher discontinuation and growth hormone-related adverse effects; the other pooled five trials, reporting a visceral fat mean difference of -27.71 cm2 and a lean body mass increase of 1.42 kg. |
| Population the evidence describes | Genetically obese and diet-induced obese rodents for efficacy, plus a small rabbit intra-articular osteoarthritis study for the cartilage claims. The human data describe tolerability rather than any population's response. | Almost entirely people living with HIV and excess abdominal fat. Extension beyond that population is limited: cognitive trials have been small and inconsistent, the largest recent HIV neurocognitive trial found no significant between-group difference, and a trial of tesamorelin with exercise for physical function has a published protocol but no results. |
| What the recent literature consists of | Anti-doping analytical chemistry, including a validated urinary detection method and identification of the peptide in seized preparations, plus narrative reviews of peptides in orthopaedics and sports medicine. | Meta-analyses of the HIV lipodystrophy trials, MASLD reviews, preclinical GHRH-agonist neurobiology in Alzheimer's models, and a trial protocol for physical function. |
And what it does not.
These two compounds are grouped by marketing rather than by evidence, and nothing published compares them. What each literature separately supports is very different in weight. Tesamorelin has randomised placebo-controlled multicentre trials with imaging-based primary endpoints, an approval, and two independent 2026 meta-analyses converging on modest visceral and hepatic fat reduction with a lean-mass increase, alongside recorded adverse effects including arthralgia, myalgia, paraesthesia, higher discontinuation and IGF-1 elevation. Its evidence describes people living with HIV and excess abdominal fat, and attempts to extend it to cognition and physical function have so far been small, inconsistent or unreported. AOD-9604 has a coherent preclinical story from 1993 to 2001 in rodents, a pooled human safety and tolerability analysis showing no IGF-1 effect and no carbohydrate-metabolism signal, and a non-clinical toxicology package, but no published standalone efficacy trial in humans for any indication. The absence of an efficacy report is not evidence that the compound does nothing, and the presence of an approval for the other compound is not evidence that it works in populations it was never tested in. Neither has controlled evidence for cosmetic fat loss in otherwise healthy people, and for AOD-9604 the cartilage and injectable-use claims rest on a single small rabbit study with no human confirmation.
Common questions.
- Do these two compounds both act through growth hormone?
They act in opposite relationships to the axis. Tesamorelin is a growth hormone-releasing hormone analogue that raises endogenous pulsatile growth hormone and consequently IGF-1. AOD-9604 was developed on the premise of separating lipolytic activity from that axis: preclinical binding experiments indicated no interaction with the growth hormone receptor, and the pooled human safety analysis reported no effect on serum IGF-1.
- Has AOD-9604 completed a published randomised efficacy trial?
Not as a standalone peer-reviewed report. Human obesity trials were conducted and their pooled safety and tolerability data were published in 2013, covering six randomised double-blind placebo-controlled studies, but body-composition efficacy outcomes have not appeared as an indexed standalone publication or been independently replicated.
- What did the tesamorelin trials measure when they reported fat loss?
Imaging-based fat compartments in people living with HIV and abdominal fat accumulation. A 412-participant randomised trial reported a 15.2% fall in visceral adipose tissue against a 5.0% rise on placebo, and a 61-participant NAFLD trial reported an absolute 4.1% reduction in hepatic fat fraction with 35% of recipients falling below a 5% fraction versus 4% on placebo. Two 2026 meta-analyses pooled these and related trials.
- Is there evidence for either compound in people without HIV-associated lipodystrophy?
Very little. The tesamorelin evidence base is concentrated almost entirely in people living with HIV; cognitive trials outside that setting have been small and inconsistent, and a trial testing tesamorelin alongside exercise for physical function has a published protocol but no reported results. For AOD-9604 no published standalone efficacy report exists in any population.
- Where do the cartilage and joint claims for AOD-9604 come from?
From one small animal experiment. A collagenase-induced knee osteoarthritis study in 32 rabbits compared weekly intra-articular saline, hyaluronic acid, AOD9604, and AOD9604 with hyaluronic acid, reporting less cartilage degeneration and shorter lameness in the treated groups. There is no human confirmation, and orthopaedic reviews covering the peptide note the absence of clinical trials.
For research purposes only. Not for human consumption, diagnosis, treatment, or prevention of any condition. Nothing on this page is medical advice, and no comparison here should be read as a recommendation of either compound.