AOD-9604 vs Tesamorelin: differences, evidence and safety

Tesamorelin, FDA-approved as Egrifta, cut deep belly fat by 15.2% in a 412-person phase 3 trial in people with HIV. AOD-9604, a growth-hormone fragment, was well tolerated in trials of about 900 volunteers, but it is not FDA-approved and failed a 24-week weight-loss trial.

The evidence gap is wide. Tesamorelin rests on two phase 3 randomized trials and an FDA label, but its approval covers one use only: excess abdominal fat in adults with HIV-associated lipodystrophy, a condition where fat collects around the organs. AOD-9604’s six human trials were run and funded by its developer, and no peer-reviewed report of the weight results from its two larger trials was found on PubMed (searched 2026-10-17). Both are prohibited in sport at all times.

Item	AOD-9604	Tesamorelin
US FDA	Not approved; obesity development ended in 2007 (Misra 2013)	Approved as Egrifta, 2010-11-10, BLA 022505 (Drugs@FDA); latest label 2025-03-25
Compounding	Nomination withdrawn; listed as “withdrawn” on FDA’s Category 2 page (current 2026-04-22), with no new category given; next step: none announced	A biologic since 2020-03-23, so not eligible for 503A/503B exemptions (FDA)
WADA (2026 List)	Prohibited at all times, S0 non-approved substances (USADA on S0)	Prohibited at all times, peptide hormones class (USADA)
WADA 2027 List	Not yet checked against WADA’s published 2027 List (WADA)
Strongest evidence	Human RCTs run by the sponsor; weight results not peer-reviewed; the 24-week trial failed	Approved label backed by two phase 3 RCTs
Human trials	6 sponsor trials, about 900 people (Stier 2013); 0 on ClinicalTrials.gov	24 on ClinicalTrials.gov, e.g. NCT00123253, NCT02196831
Last checked	2026-10-17

AOD-9604 vs tesamorelin at a glance

Feature	AOD-9604	Tesamorelin
What it is	Modified fragment of human growth hormone (Tyr-hGH 177–191)	Modified copy of human GHRH (44 amino acids)
Class	Growth-hormone fragment	GHRH analogue
Mechanism	Fat breakdown in fat tissue (animal); no IGF-1 rise in human trials	Binds GHRH receptors; raises the body’s own GH
Main research focus	Obesity (stopped 2007); cartilage in animals	HIV-associated belly fat; liver fat
Human evidence	6 sponsor trials, about 900 people	24 registered trials; 2 phase 3 RCTs
Approval	None (FDA)	FDA-approved (Egrifta); EU application withdrawn
WADA	S0, prohibited at all times	Peptide hormones class, prohibited at all times
Routes studied	IV and oral (human); into the joint (rabbit)	Injection under the skin
Timelines in studies	12 and 24 weeks	26 to 52 weeks; 12 months for liver fat
Main safety concerns	Long-term effects unknown; FDA flags immunogenicity and impurity risks in compounded forms	IGF-1 rise, glucose intolerance, fluid retention, injection-site reactions

What is AOD-9604?

AOD-9604 is a 16-amino-acid peptide based on the tail end of human growth hormone (amino acids 177–191, plus a tyrosine). Its developer, Metabolic Pharmaceuticals, designed it to keep growth hormone’s fat-reducing action without its unwanted effects (Stier 2013). In obese rats, oral AOD-9604 cut body-weight gain by more than half, 15.8 g against 35.6 g [Animal] (Ng 2000). The company then tested it in about 900 people. Development for obesity ended in 2007 after a 24-week trial failed to show significant weight loss (Misra 2013). It has no FDA approval.

What is tesamorelin?

Tesamorelin is the full 44-amino-acid sequence of human growth-hormone-releasing hormone (GHRH) with a short fatty chain attached. It is sold as Egrifta, and its label indication is the “reduction of excess abdominal fat in HIV-infected adult patients with lipodystrophy” (Egrifta WR label). It was approved on 2010-11-10, and the latest label supplement, for the Egrifta WR form, is dated 2025-03-25 (Drugs@FDA). Our comparison of tesamorelin with ipamorelin and sermorelin covers how it differs from other growth-hormone releasers.

How they work differently

• AOD-9604: works on fat tissue itself. In obese mice it raised fat burning (fat oxidation) and reduced weight gain [Animal] (Heffernan, Int J Obes 2001).
  Tesamorelin: works upstream, on the pituitary gland. It binds GHRH receptors “with similar potency as the endogenous GRF” and triggers pulses of the body’s own growth hormone (label).
• AOD-9604: did not raise IGF-1 (insulin-like growth factor 1, the hormone behind most of growth hormone’s growth effects) in human trials (Stier 2013).
  Tesamorelin: raises IGF-1 by design. After 26 weeks, 47% of treated patients had IGF-1 above 2 standard deviation scores (label).
• AOD-9604: in mice lacking the beta-3 adrenergic receptor, a fat-cell receptor that triggers fat breakdown, its long-term effects disappeared, though single doses still raised energy use [Animal] (Heffernan, Endocrinology 2001).
  Tesamorelin: depends on a working growth-hormone axis, and the label rules it out for people whose hypothalamic-pituitary axis is disrupted.

Evidence head-to-head

Each cell gives the best evidence found for that option. Figures from different trials are cross-trial: different people, designs and endpoints, so the numbers cannot be compared directly.

Outcome	AOD-9604 best evidence	Tesamorelin best evidence
Visceral (belly) fat	No human data found. Animal: less fat in obese mice (Heffernan 2001)	Human RCT (n=412): −15.2% vs +5.0% on placebo at 26 weeks (Falutz 2007)
Body weight	Human RCT: 2.6 kg vs 0.8 kg at 12 weeks; 24-week RCT (n=536): no significant loss (Misra 2013)	Approved label: not indicated for weight loss; trunk fat −1.0 to −0.8 kg, lean mass +1.3 to +1.2 kg (label)
Liver fat	No study found	Human RCT (n=61): liver fat −4.1 points vs placebo, p=0.018 (Stanley 2019)
Blood sugar	Human RCT: no glucose-tolerance difference at 24 weeks, P=0.63 (Stier 2013)	Label: HbA1c ≥6.5% in 5% vs 1% on placebo
Joint cartilage	Animal: better cartilage scores in rabbit knee arthritis (Kwon 2015)	No study found
Long-term safety	No data beyond 24 weeks found	Label: long-term heart safety not established

Tesamorelin’s main benefit has been replicated. In the second phase 3 trial, visceral fat fell 14% against a 2% fall on placebo (Egrifta label). In a separate six-month trial, visceral fat changed by −34 cm² on tesamorelin against +8 cm² on placebo, and liver fat by a median −2.0 points against +0.9 (p=0.003) [Human RCT] (Stanley 2014). AOD-9604’s strongest result, the 12-week weight loss, is reported in a journal review of company results (Misra 2013), not in a peer-reviewed trial report. Its developer funded all six trials, and one author of the safety paper held a stake in the developer’s parent company (Stier 2013). The two sources also disagree on the size of the 24-week trial: 502 adults (Stier) or 536 (Misra).

Which fits which goal?

Tesamorelin has more evidence for reducing visceral belly fat and liver fat, but only in adults with HIV. Two phase 3 trials and later liver studies back it, and the FDA approved it for that use. Its label excludes weight-loss use (label). Our page on tesamorelin evidence and safety in women covers who was studied.

AOD-9604 has more evidence for leaving IGF-1 and blood sugar unchanged, because its trials measured those things directly (Stier 2013). For weight loss, its longest trial failed. For joints, the evidence is a single rabbit study.

Searches that add retatrutide to this pair are reaching for a different class, the incretin drugs, compared in retatrutide vs CagriSema: trials, FDA timeline and safety. A clinician is the person to decide whether any of these fits an individual.

Can AOD-9604 and tesamorelin be taken together?

Searches often pair the two, sometimes with MOTS-c or ipamorelin in a blend. ClinicalTrials.gov lists no registered trial of AOD-9604 at all (searched 2026-10-17), so none of these blends has a registered trial there. No controlled human study of the combination was found on PubMed or ClinicalTrials.gov (searched 2026-10-17). Whether the two add to each other’s effects, or whether combining them changes the safety picture, is unknown. MOTS-c is compared with another metabolic compound in MOTS-c vs 5-Amino-1MQ: evidence and safety, and tesamorelin is set against an ipamorelin pairing in tesamorelin vs CJC-1295 + ipamorelin for fat loss.

Safety and regulatory status

United States. Tesamorelin is a prescription biologic. Its label lists IGF-1 rises, glucose intolerance (HbA1c ≥6.5% in 5% vs 1% on placebo), hypersensitivity in 4%, fluid retention (swelling, joint pain, carpal tunnel syndrome) and injection-site reactions in 25% vs 14% on placebo (Egrifta WR label). Joint pain affected 13% vs 11%, and swelling of the limbs 6% vs 2%. It must not be used in pregnancy, with active cancer, or with a disrupted hypothalamic-pituitary axis. As a biologic it is not eligible for the compounding exemptions (FDA).

AOD-9604 has no FDA approval. In the sponsor’s 24-week trial, 78.7% of participants had at least one adverse event and 3.6% a serious one; the authors judged its profile “indistinguishable from placebo” across the six trials (Stier 2013). FDA writes that compounded AOD-9604 “may pose significant risk for immunogenicity” (an immune reaction against the drug) and that it lacks enough information to know whether it causes harm in people (FDA Category 2 page). Being moved to that page’s withdrawn-nominations table is not an approval.

European Union. Tesamorelin’s EU application was withdrawn on 2012-06-21. Reviewers at the time cited IGF-1-related cancer and diabetic eye-disease concerns, fat loss “not shown to be clinically meaningful in terms of actual health benefits”, and no long-term safety data (EMA).

Sport. Tesamorelin is prohibited at all times (USADA). AOD-9604 falls under S0, which covers substances “not approved by any government regulatory authority” (USADA).

Anyone who suspects a side effect from AOD-9604, tesamorelin or any other drug or product can report it to the FDA through MedWatch.

How long do effects take in studies?

• Tesamorelin: visceral fat fell over 26 weeks in both phase 3 trials. Between weeks 26 and 52, patients who stayed on the drug kept their loss, while those switched to placebo regained 24–25 cm² (label). The liver-fat result was measured at 12 months (Stanley 2019).
• AOD-9604: the weight difference was reported at 12 weeks; at 24 weeks it was not significant (Misra 2013).