# AOD-9604 vs Tesamorelin: hGH Fragment versus GHRH Analog Comparison

> Tesamorelin (Egrifta) has Phase 3 visceral-fat data; AOD-9604 is an hGH fragment with rodent lipolysis studies and no PubMed-indexed obesity RCT.

Source: https://peptpedia.org/compare/aod-9604-vs-tesamorelin | Published: 2026-08-27 | Last updated: 2026-08-27

## Executive Summary

Tesamorelin is an FDA-approved GHRH analog with Phase 3 evidence that 2 mg daily reduced visceral adipose tissue 15.4% versus placebo at 26 weeks in 806 HIV-infected patients, sparing abdominal subcutaneous fat (PMID: 20554713). AOD-9604 is a synthetic C-terminal hGH fragment studied for lipolysis in rodents (PMID: 11146367, PMID: 11713213) and for cartilage histology in a rabbit osteoarthritis model (PMID: 26275694). PubMed does not index a randomized obesity trial of AOD-9604; a 2004 pipeline review reported Phase IIa work underway (PMID: 15134286). One is a GHRH analog with a labeled indication. The other is an unapproved fragment with preclinical metabolic and joint data.

## Side-by-Side Comparison

| Property | AOD-9604 | Tesamorelin |
| --- | --- | --- |
| Other names | Anti-Obesity Drug 9604; Tyr-hGH fragment (C-terminal analog) | Egrifta; Egrifta SV; TH9507 |
| Peptide class | Modified C-terminal fragment of human GH | Stabilized GHRH(1-44) analog |
| Sequence notes | 16-amino-acid analog of the hGH lipolytic domain (Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe) | Trans-3-hexenoic acid N-terminal GHRH analog |
| Molecular weight | 1815.08 g/mol | 5135.85 g/mol |
| Primary mechanism (published) | Rodent lipolysis and reduced weight gain without the insulin-sensitivity impairment of intact hGH; lipolysis not mediated directly through β3-AR (PMID: 11146367, PMID: 11713213) | Pituitary GHRH-receptor agonism → endogenous GH/IGF-I → selective VAT reduction in HIV lipodystrophy trials |
| IGF-1 | Rodent work framed as avoiding intact-hGH diabetogenic/IGF-axis effects; no PubMed-indexed human IGF-I RCT | Pooled Phase 3: IGF-I +108 versus −7 ng/mL versus placebo at week 26 (PMID: 20554713) |
| Half-life (as reported) | Short plasma half-life; no formal human PK paper among the citations here | 26-38 minutes after subcutaneous injection; studied as once-daily 2 mg |
| Evidence tier | Rodent metabolic studies; rabbit intra-articular OA model; no PubMed-indexed obesity RCT | Multiple Phase 3 RCTs plus a liver-fat RCT |
| Regulatory status | Not approved as a drug in any country; a GRAS food-ingredient listing is not a drug approval | FDA-approved (Egrifta/Egrifta SV) for excess abdominal fat in HIV-associated lipodystrophy |
| Administration as studied | Oral 500 µg/kg daily in obese Zucker rats (PMID: 11146367); intraperitoneal chronic dosing in mice (PMID: 11713213); weekly intra-articular injections in rabbits (PMID: 26275694) | 2 mg subcutaneous daily in human Phase 3 (PMID: 18057338, PMID: 20554713) |
| Key studies | Ng 2000 Zucker rats; Heffernan 2001 obese and β3-AR knockout mice; Kwon 2015 rabbit OA; Wilding 2004 development review | Falutz NEJM 2007; Falutz pooled JCEM 2010 (n=806); Stanley JAMA 2014 |
| Human RCT status | No PubMed-indexed randomized obesity trial located | Completed Phase 3 program; labeled indication |

## Mechanism Differences: GH Fragment versus GHRH Analog

[AOD-9604](https://peptpedia.org/peptide/aod-9604) and [tesamorelin](https://peptpedia.org/peptide/tesamorelin) are both discussed in fat-loss research, but they are not the same pharmacologic class.

**AOD-9604** is a synthetic analog of the C-terminal lipolytic domain of human GH. Ng et al. treated obese Zucker rats with oral AOD9604 500 µg/kg daily for 19 days: body-weight gain was 15.8 ± 0.6 g versus 35.6 ± 0.8 g in controls, adipose tissue showed increased lipolytic activity, and euglycemic clamps did not show the insulin-sensitivity impairment seen with chronic intact hGH (PMID: 11146367). Heffernan et al. then showed that both hGH and AOD9604 reduced body weight and fat in obese mice and increased β3-adrenergic receptor RNA, but that lipolytic actions were *not* mediated directly through the β3-AR. Chronic treatment in β3-AR knockout mice failed to reproduce the body-weight and lipolysis changes seen in wild-type mice, though an acute experiment still increased energy expenditure and fat oxidation in knockouts (PMID: 11713213). In short, the chronic fat-loss signal in mice needs an intact β3-AR pathway, without AOD9604 acting as a simple direct β3-AR agonist.

**Tesamorelin** is a [GHRH analog](https://peptpedia.org/research/tesamorelin-ghrh-analog-pharmacology). It stimulates pituitary GH release. The VAT reduction in HIV lipodystrophy trials is a GH-axis, whole-body effect measured on CT, not a fragment acting on adipocyte lipolysis in isolation (PMID: 18057338, PMID: 20554713).

AOD-9604 is not a GHRH analog, and tesamorelin is not an hGH 176-191 fragment.

## Clinical Evidence: Human Phase 3 versus Preclinical AOD-9604

### Tesamorelin

Pooled Phase 3 (n=806): tesamorelin 2 mg daily for 26 weeks reduced VAT 15.4% versus placebo, preserved abdominal SAT, lowered triglycerides (treatment effect −12.3%), and raised IGF-I (PMID: 20554713). The NEJM trial (n=412) reported VAT −15.2% versus +5.0% placebo (PMID: 18057338). Stanley et al. (n=50) added a liver-fat reduction (median lipid-to-water percentage −2.0% versus +0.9% placebo, P=0.003) (PMID: 25038357). These are human, imaging-based RCTs in HIV-associated abdominal fat accumulation.

### AOD-9604

Published efficacy is preclinical. Ng 2000 and Heffernan 2001 are rodent metabolic studies (PMID: 11146367, PMID: 11713213). Kwon and Park injected AOD9604 weekly into collagenase-induced osteoarthritic rabbit knees, with or without hyaluronic acid, and reported better morphological and histopathological cartilage scores and a shorter lameness period, especially for the combination, versus saline (PMID: 26275694). That work is a rabbit OA model, not a human osteoarthritis or obesity trial.

Wilding’s 2004 development review said Metabolic was developing AOD-9604 for obesity and that Phase IIa trials were underway by February 2002 (PMID: 15134286). The abstract has no Phase IIa or IIb efficacy numbers. A PubMed search for AOD9604 and AOD-9604 on 27 August 2026 did not return a randomized human obesity trial, so press-recap enrollment and kilogram-change figures are left out.

## Safety Findings in the Literature

**Tesamorelin.** Pooled Phase 3: generally well tolerated; no clinically meaningful glucose differences at weeks 26 and 52 despite IGF-I elevation (PMID: 20554713). NEJM: similar overall adverse-event rates, more withdrawals for adverse events on tesamorelin (PMID: 18057338). Stanley: transient fasting-glucose rise at 2 weeks, not significant at 6 months (PMID: 25038357). These data are from the HIV-lipodystrophy 2 mg daily program.

**AOD-9604.** Ng reported no insulin-sensitivity impairment in Zucker rats relative to intact hGH (PMID: 11146367). Kwon reported a rabbit intra-articular series, not a human safety database (PMID: 26275694). There is no PubMed-indexed randomized human safety trial among the citations above. Missing human RCTs do not establish safety.

## Regulatory and Research Status

**Tesamorelin** is FDA-approved (Egrifta/Egrifta SV) for excess abdominal fat in HIV-associated lipodystrophy. That is a labeled drug indication, not a general weight-loss license.

**AOD-9604** has no drug approval in any country. GRAS status, where it applies, is a food-ingredient category and does not show anti-obesity efficacy. Wilding 2004 describes an obesity development program that, in this PubMed search, never produced an indexed pivotal trial (PMID: 15134286).

## Research Verdict

For human visceral-fat evidence, tesamorelin is the studied drug: a defined HIV-lipodystrophy population, with CT VAT as the Phase 3 endpoint. That is not a head-to-head win against AOD-9604 in a trial that was never run, and it is not a general obesity ranking.

AOD-9604 has rodent lipolysis and weight-gain data and a rabbit cartilage model. PubMed does not index a human obesity RCT. The cartilage findings are preclinical.

Human AOD-9604 efficacy and safety at any metabolic indication remain unpublished in indexed trials. So does any tesamorelin versus AOD-9604 comparison, and so does translation of the rodent lipolysis signal.

## Frequently Asked Questions

### Is AOD-9604 or tesamorelin better for fat loss?

Tesamorelin has Phase 3 CT evidence for visceral fat reduction in HIV lipodystrophy (PMID: 20554713). AOD-9604’s published fat data are rodent studies (PMID: 11146367, PMID: 11713213). No PubMed-indexed human obesity RCT was located, so there is no trial ranking outside tesamorelin’s study population.

### Did AOD-9604 fail a Phase 2b obesity trial?

A 2004 review reported Phase IIa development underway (PMID: 15134286). No PubMed-indexed Phase 2b paper with enrollment and outcomes was found. A 536-person “failed versus placebo” recap is not used as a primary source.

### Can AOD-9604 and tesamorelin be combined?

No published combination trial was found. They act through different mechanisms (GH fragment lipolysis in rodents versus GHRH-receptor agonism in humans), so combined efficacy and safety are unknown.

### Is tesamorelin FDA-approved? Is AOD-9604?

Tesamorelin is FDA-approved as Egrifta/Egrifta SV for excess abdominal fat in HIV-associated lipodystrophy. AOD-9604 is not approved as a drug. Food-ingredient GRAS status is not a therapeutic approval.

### Does AOD-9604 work through the GH receptor like tesamorelin’s GH rise?

Tesamorelin raises endogenous GH and IGF-I via the GHRH receptor (PMID: 20554713). AOD-9604 was studied as a C-terminal hGH fragment that produced lipolysis in rats without intact-hGH’s clamp-measured insulin-sensitivity cost (PMID: 11146367). Heffernan et al. found chronic lipolytic body-weight effects in mice were not a direct β3-AR agonist effect (PMID: 11713213). It is not a GHRH analog.

### What human data exist for AOD-9604 in joints?

The principal indexed study is Kwon and Park 2015: intra-articular AOD9604, with or without hyaluronic acid, in a collagenase-induced rabbit knee OA model, with histologic and lameness endpoints (PMID: 26275694). It is a rabbit study, not a human osteoarthritis trial.

## References

1. Ng FM, Sun J, Sharma L, et al.. "Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone.." *Hormone research* (2000). [PMID 11146367](https://pubmed.ncbi.nlm.nih.gov/11146367/) | [doi:10.1159/000053183](https://doi.org/10.1159/000053183)
2. Heffernan M, Summers RJ, Thorburn A, et al.. "The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice.." *Endocrinology* (2001). [PMID 11713213](https://pubmed.ncbi.nlm.nih.gov/11713213/) | [doi:10.1210/endo.142.12.8522](https://doi.org/10.1210/endo.142.12.8522)
3. Kwon DR, Park GY.. "Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model.." *Annals of clinical and laboratory science* (2015). [PMID 26275694](https://pubmed.ncbi.nlm.nih.gov/26275694/)
4. Wilding J.. "AOD-9604 Metabolic.." *Current opinion in investigational drugs (London, England : 2000)* (2004). [PMID 15134286](https://pubmed.ncbi.nlm.nih.gov/15134286/)
5. Falutz J, Allas S, Blot K, et al.. "Metabolic effects of a growth hormone-releasing factor in patients with HIV.." *The New England journal of medicine* (2007). [PMID 18057338](https://pubmed.ncbi.nlm.nih.gov/18057338/) | [doi:10.1056/NEJMoa072375](https://doi.org/10.1056/NEJMoa072375)
6. Falutz J, Mamputu JC, Potvin D, et al.. "Effects of tesamorelin (TH9507), a growth hormone-releasing factor analog, in human immunodeficiency virus-infected patients with excess abdominal fat: a pooled analysis of two multicenter, double-blind placebo-controlled phase 3 trials with safety extension data.." *The Journal of clinical endocrinology and metabolism* (2010). [PMID 20554713](https://pubmed.ncbi.nlm.nih.gov/20554713/) | [doi:10.1210/jc.2010-0490](https://doi.org/10.1210/jc.2010-0490)
7. Stanley TL, Feldpausch MN, Oh J, et al.. "Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial.." *JAMA* (2014). [PMID 25038357](https://pubmed.ncbi.nlm.nih.gov/25038357/) | [doi:10.1001/jama.2014.8334](https://doi.org/10.1001/jama.2014.8334)

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