AOD-9604

How it works

• It copies the last 15 amino acids of growth hormone, with a tyrosine added at the front for stability. A bond between two cysteines closes part of it into a ring.
• In rat fat tissue, the unmodified parent fragment switched on a fat-breakdown enzyme (hormone-sensitive lipase) and blocked a fat-building enzyme.
• In obese mice, AOD-9604 reduced weight gain and increased fat burning.
• In lab tests, it did not bind the growth-hormone receptor. In mice, unlike growth hormone, it did not raise blood sugar.
• Its exact target in the body is unknown.

Evidence

Caveats

• All human safety data come from the developer's own trials. These gave it by mouth for up to 24 weeks, or as a few single doses into a vein. No trial tested repeated injections under the skin.
• The full efficacy results of both obesity trials were never published in a peer-reviewed journal.
• In the 12-week trial, five serious events occurred, all in people taking it, including four skin or breast cancers. Investigators judged them unrelated; a later safety review said this could not be assessed.
• Reported side effects included headache and, at the highest oral dose, diarrhea and gas. A few people given it into a vein reported euphoria.
• The developer's summary reported no rise in IGF-1 and no effect on blood sugar handling. Independent researchers have not checked this.
• Animal studies raised questions about bone turnover in rats and liver-cell changes in monkeys.
• The peptide tends to break down and clump, which may raise the risk of immune reactions when it is injected. It has turned up in vials seized in the US.
• There are no safety data in pregnancy.

References

1. Ng FM, et al. J Mol Endocrinol. 2000;25:287-298.
2. Heffernan MA, et al. Int J Obes Relat Metab Disord. 2001;25:1442-1449.
3. Valentino MA, et al. Clin Pharmacol Ther. 2010;87:652-662.
4. Stier H, et al. J Endocrinol Metab. 2013;3:7-15.
5. Kwon DR, Park GY. Ann Clin Lab Sci. 2015;45:426-432.