AOD-9604 Side Effects, Withdrawal, and Discontinuation Syndrome: What the Evidence Shows

Is there a withdrawal syndrome when AOD-9604 is stopped?

No withdrawal or discontinuation syndrome has been established for AOD-9604, and whether stopping it causes symptoms is unknown [1]. AOD-9604 is not full-length growth hormone: it is a 16-amino-acid fragment of hGH with an added tyrosine at the N-terminus, which is why it is also called hGH fragment 176-191 [4]. Preclinical work found no growth-hormone-receptor binding, though that is animal and laboratory work rather than a description of what happens in people after stopping [1].

What side effects are documented in humans?

AOD-9604 is not FDA-approved, so there is no FDA-approved label listing adverse-reaction rates or warnings [2].

The main human obesity study described in a 2026 review lasted 24 weeks and tested AOD-9604 as an oral drug candidate: 534 people were enrolled and 502 randomized, and it failed to show a significant benefit on the primary weight-loss endpoint [1]. Earlier phase IIa trials were underway by February 2002 [3]. The 2026 review notes that the 24-week result rests on sponsor-reported phase 2 results rather than a peer-reviewed randomized paper, and describes human evidence on the peptide as limited and largely short-term [1].

On its page about bulk substances that may present significant safety risks when compounded, FDA lists AOD-9604 among substances nominated but later withdrawn by the nominator. FDA says it has identified serious adverse events that may be associated with AOD-9604, though causality is not clear, and gives no details. Removal from the earlier category was not a finding that the substance is safe [2].

What about injected AOD-9604 sold online?

No approved dose exists [1]. The human obesity study tested an oral candidate, not an injected product [1]. For compounded drugs containing AOD-9604, FDA cites immunogenicity risk for certain routes of administration, tied to peptide impurities and characterization problems, and states that it has identified no or only limited safety information on the substance [2]. AOD-9604 has been identified in vials seized by the Belgian authorities and in confiscated vials in the United States [6][4].

Is AOD-9604 approved, covered by FDA compounding policy, or banned in sport?

AOD-9604 is not FDA-approved. FDA's category 1 compounding policy does not cover it, and WADA prohibits it at all times [7][8][9][5].

It was developed by an Australian company as an anti-obesity candidate, and the program was later dropped [3][1]. FDA's GRAS Notice Inventory contains no AOD-9604 notice [10]. GRAS is a food-ingredient concept and would not make an injected or compounded drug lawful or safe [10].

AOD-9604 appears in none of the three categories on FDA's list for state-licensed pharmacies and physicians, or on the list for outsourcing facilities [7][8][9]. It is also not among the six peptides in HHS's draft enforcement-discretion policy for compounding [11][12].

In sport, WADA's Prohibited List names AOD-9604 and hGH 176-191 in section S2.2.3, prohibited at all times in and out of competition, on the 2026 and 2027 Lists [5][13].