AOD-9604

It's a rare grey-market peptide that actually entered clinical development. It sat the real exams (proper human trials) and failed the decisive one. The fat-burning story that looked good in mice did not show up convincingly when hundreds of real people were tested, so the company that owned it withdrew. That it is 'safe' is true but beside the point. A sugar pill is also safe.

Designed as the isolated lipolytic fragment of human growth hormone (C-terminal residues 176-191 plus an added N-terminal tyrosine). In rodent and in-vitro models it stimulated lipolysis, inhibited lipogenesis and increased beta-3 adrenoceptor expression in adipocytes. Its lipolytic effect was lost in beta-3-AR knock-out mice, implying beta-3-AR signalling is required, though the peptide does not appear to be a direct receptor agonist. Across human trials it did not raise IGF-1 and did not impair glucose metabolism. The intended selling point was fat loss without growth hormone's metabolic downsides. However, the mechanism that worked in mice did not translate into clinically meaningful fat loss in the pivotal human trial.

Research contexts. Not proven uses, and not recommendations.

Substantial for a peptide of this type, but negative on efficacy. Metabolic Pharmaceuticals ran six human clinical trials (2001-2006) involving roughly 893-900 participants. An earlier Phase 2a multicentre RCT in obese adults (about 300 people over 12 weeks) reported a small but statistically significant weight loss (roughly 2.6 kg at the active dose vs ~0.8 kg for placebo). The safety profile was reassuring: adverse events comparable to placebo, no effect on IGF-1, no adverse effect on glucose or insulin. The larger pivotal Phase 2b trial (about 536 people over 24 weeks) did not show statistically significant weight loss over placebo. The company terminated development as a weight-loss drug around 2007. The human data do not support a clinically meaningful effect on body weight or fat mass.

• !Efficacy is the core problem. The pivotal human trial failed and the drug was abandoned in 2007. The marketing pitch ('GH fat-burning without the downsides') was not borne out in people.
• !Marketing emphasises mouse and in-vitro data and the favourable safety profile while omitting the negative human efficacy result.
• !GRAS status is routinely misrepresented online as a weight-loss approval. It is a US food-ingredient self-affirmation category and says nothing about clinical efficacy as a drug.
• !Sold as an unlicensed 'research chemical' labelled 'not for human consumption'. Purity, concentration, sterility and even peptide identity are unverified in grey-market products.
• !Banned in sport under WADA S0 (non-approved substances). Athletes face sanctions.
• !No long-term human safety data beyond the original trial follow-up periods. Injectable use carries sterility and injection-site risks.

Not a licensed medicine in the UK. AOD-9604 has no Marketing Authorisation from the MHRA, EMA or FDA for any indication. It is an unlicensed, investigational compound whose drug development was discontinued. Selling or supplying it with therapeutic or weight-loss claims without authorisation breaches the Human Medicines Regulations 2012. In practice it is sold online as an unlicensed 'research chemical' labelled 'not for human consumption', a framing used to sidestep medicines law. It is also prohibited in sport under the WADA Prohibited List (category S0, non-approved substances).

• · Phase 2a· Completed; small but statistically significant weight-loss signal reported

  Metabolic Pharmaceuticals AOD-9604 obesity programme: early Phase 2a multicentre RCT in obese adults

  About 300 obese adults over ~12 weeks; active dose lost ~2.6 kg vs ~0.8 kg placebo; safety comparable to placebo.

• · Phase 2b· Completed; failed primary efficacy endpoint

  Metabolic Pharmaceuticals AOD-9604 pivotal Phase 2b obesity trial

  About 536 adults over ~24 weeks; failed to show statistically significant weight loss vs placebo; led to termination of drug development around 2007. NCT identifier not confirmed.

1. 01
   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 — Heffernan MA, Summers RJ, Thorburn AW, et al., Endocrinology (2001)

   Landmark preclinical paper establishing the lipolytic effect and beta-3-AR dependence in mice; the strongest positive (animal) evidence. PMID not independently confirmed here, so a PubMed search link is given.

2. 02
   Safety and Tolerability of the Hexadecapeptide AOD9604 in Humans — Stier H, Vos E, Kenley D, Journal of Endocrinology and Metabolism, 2013;3(1-2):7-15

   Pooled safety analysis across the six human trials (~893 subjects): adverse events indistinguishable from placebo, no effect on IGF-1, no adverse effect on glucose/insulin. Supports the safety claims; says nothing positive about efficacy.

3. 03
   The effect of AOD9604 on weight loss in obese adults: results of a randomized, double-blind, placebo-controlled, multicenter study — Stier H, et al., Reported clinical trial (Metabolic Pharmaceuticals Phase 2 programme)

   The early human RCT reporting a small, statistically significant weight-loss signal; the later pivotal Phase 2b trial failed. Exact identifier not confirmed, so a descriptive citation with a PubMed search link is given.

4. 04
   WADA statement on substance AOD-9604, World Anti-Doping Agency (2013)

   Confirms prohibited status in sport under S0 (non-approved substances), 22 April 2013.