Need help or have questions about your order? Call 510-991-8265Questions about your order? Call 510-991-8265

Sign InShop GLPs
Shop GLPs

AOD-9604 Hair and Skin Changes: What the Evidence Actually Shows

By
Published Updated Last reviewed
9 linked public sourcesEditorial, sourcing, and corrections policy

At a glance

  • What it is / 16-amino-acid fragment of hGH (177 to 191 plus an N-terminal tyrosine) [2]
  • FDA approval / None, for any indication [1][4]
  • Human hair or skin studies / None identified
  • GH receptor binding / Not detected in preclinical work [1]
  • Human obesity trial / 24 weeks, oral, 502 randomized, failed primary endpoint [1]
  • FDA safety note / Serious adverse events identified, causality unclear [4]

Does AOD-9604 change hair or skin?

No study has been identified that measured hair density, shedding, skin thickness, collagen or sebum in people taking AOD-9604. The human data described for it come from a 24-week oral obesity study: 534 people enrolled, 502 were randomized, and it did not show a significant benefit on its primary weight-loss endpoint. The 2026 review describing that trial notes the result rests on sponsor-reported phase 2 data rather than peer-reviewed randomized trials [1].

A rabbit knee study examined cartilage after AOD-9604 was injected into the joint. It does not establish an effect on human hair or skin [5].

Why a fragment of growth hormone is not growth hormone

AOD-9604 is hGH amino acids 177 to 191 with an extra tyrosine at the N-terminus, 16 amino acids in total, which is why it is also called hGH fragment 176-191 [2]. Preclinical work found no growth-hormone-receptor binding, and human data on IGF-1 and body composition are too limited to say more [1].

In a laboratory study of cultured human hair follicles, IGF-I stimulated follicle growth in a dose-dependent manner when insulin was absent, while growth hormone had no effect on follicle growth or morphology [6]. Whether AOD-9604 affects IGF-1 or hair follicle cycling in a living person is not established [1].

Shedding has other documented causes

Caloric deprivation and deficiency of protein, minerals, essential fatty acids or vitamins can lead to hair loss [7], and low serum ferritin has been associated with increased shedding in women [8].

Safety and approval status

AOD-9604 never reached FDA approval, and the obesity program was later dropped [1]. FDA lists it among bulk substances nominated but withdrawn, with stated concerns about immunogenicity risk for certain routes of administration, no or only limited safety information, and serious adverse events that may be associated with AOD-9604 although causality is not clear. Removal from FDA's category 2 was not a finding that it is safe [4]. There is no approved dose [1].

Frequently asked questions

Does AOD-9604 cause hair loss?
It is not established whether AOD-9604 causes hair loss. Documented causes of shedding include caloric deprivation and deficiency of protein, minerals, essential fatty acids or vitamins [7], and low serum ferritin has been linked to increased shedding in women [8].
Can AOD-9604 improve skin or collagen?
No skin or collagen benefit has been shown in people. AOD-9604 is a 16-amino-acid fragment of hGH, not growth hormone [2].
Is AOD-9604 the same as HGH fragment 176-191?
Yes. It is hGH amino acids 177 to 191 with an extra tyrosine at the N-terminus, 16 amino acids in total, and is not full-length growth hormone [2].
What dose of AOD-9604 was studied?
There is no approved dose [1]. The human study described in a 2026 review tested an oral obesity drug candidate over 24 weeks, with 534 enrolled and 502 randomized [1]. In obese rats, 500 micrograms per kg per day by mouth for 19 days reduced weight gain to 15.8 g versus 35.6 g in controls; this is animal data, not a human dose [9].

References

  1. Dominikowski A, Rękoś Z, Olejarz M, Szczepanek-Parulska E, Domin R, RuchaŁa M. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration. Front Endocrinol (Lausanne). 2026;17:1822475. The emerging landscape of performance-enhancing peptides modulating GH-IGF1 axis: bridging the gap between clinical evidence and patient self-administration
  2. Cox HD, Smeal SJ, Hughes CM, Cox JE, Eichner D. Detection and in vitro metabolism of AOD9604. Drug Test Anal. 2015;7(1):31-8. Detection and in vitro metabolism of AOD9604
  3. Wilding J. AOD-9604 Metabolic. Curr Opin Investig Drugs. 2004;5(4):436-40. AOD-9604 Metabolic
  4. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks | FDA. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks | FDA
  5. Kwon DR, Park GY. Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model. Ann Clin Lab Sci. 2015;45(4):426-32. Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model
  6. Philpott MP, Sanders DA, Kealey T. Effects of insulin and insulin-like growth factors on cultured human hair follicles: IGF-I at physiologic concentrations is an important regulator of hair follicle growth in vitro. J Invest Dermatol. 1994;102(6):857-61. Effects of insulin and insulin-like growth factors on cultured human hair follicles: IGF-I at physiologic concentrations is an important regulator of hair follicle growth in vitro
  7. Finner AM. Nutrition and hair: deficiencies and supplements. Dermatol Clin. 2013;31(1):167-72. Nutrition and hair: deficiencies and supplements
  8. Rushton DH. Nutritional factors and hair loss. Clin Exp Dermatol. 2002;27(5):396-404. Nutritional factors and hair loss
  9. Ng FM, Sun J, Sharma L, Libinaka R, Jiang WJ, Gianello R. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Horm Res. 2000;53(6):274-8. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone
Evidence overview for AOD-9604 Hair and Skin Changes: What the Evidence Actually Shows