AOD-9604 / HGH Frag (176-191)

AOD-9604 is a short synthetic copy of the tail end of human growth hormone (hGH), the residues numbered 176-191, with an extra tyrosine added at the front. It was built by an Australian company, Metabolic Pharmaceuticals, on the idea that the fat-releasing part of growth hormone could be separated from the parts that drive tissue growth and raise blood sugar. Between the late 1990s and 2007 it went through six randomised, double-blind, placebo-controlled human trials involving roughly 900 adults, most of them clinically obese (Stier 2013). Those trials found it well tolerated, but the programme never produced an approved obesity drug, and today it is sold through compounding pharmacies and research-chemical vendors rather than as a licensed medicine.

• Body-fat reduction, which is the indication the six human trials were designed around
• Attempts to get growth-hormone-style fat loss without the joint swelling and insulin resistance of full-length hGH
• Off-label use alongside diet and training in physique and weight-management circles
• Joint and cartilage support, based on a rabbit osteoarthritis study rather than any human data
• Repurposing research into nerve pain under the development name LAT8881, which is separate from the fat-loss claims

Think of growth hormone as a long instruction sheet with several different orders written on it: release stored fat, grow tissue, push blood sugar up. AOD-9604 is a photocopy of just the last paragraph, the one about releasing fat. Because the rest of the sheet is missing, it does not bind the growth hormone receptor and does not raise IGF-1, the growth signal that full hGH switches on. The catch is that a single paragraph taken out of context turned out to be a much weaker instruction than the marketing suggests.

1. Week 1-2Human trials measured blood markers rather than how people felt, so no reliable early subjective effect is described in the literature.
2. Week 3-4Rodent studies saw reduced body-weight gain and increased fat oxidation around this point, but rodent timing does not transfer to people.
3. Week 12The 300-subject 12-week trial (METAOD005) ran to this point; the published reporting covers safety, with no peer-reviewed efficacy figures available.
4. Week 24The largest trial (METAOD006, 502 obese adults) ended here, and no approved weight-loss product came out of it.
5. Beyond 24 wksNo published human data exists past 24 weeks, so long-term effects are unknown rather than reassuring.

• Headache, reported as mild to moderate across the pooled trials (Stier 2013)
• Gastrointestinal complaints including diarrhoea and flatulence (Stier 2013)
• Infections, recorded as a common adverse event category in the same pooled analysis
• Five serious adverse events occurred during the 12-week trial — four cancer diagnoses (basal cell carcinoma, squamous cell carcinoma, breast cancer and malignant melanoma) plus a benign lipoma; the investigators judged them unrelated to treatment, and that is a judgement rather than a settled question
• No anti-AOD9604 antibodies were detected in the subset assayed, and no drug-related withdrawals or drug-related serious adverse events occurred in any of the six trials (Stier 2013)
• Injection-site reactions are not characterised in the published trials, because the human studies used oral and intravenous dosing rather than the subcutaneous route used off-label today

• You are pregnant, trying to conceive, or breastfeeding; no human reproductive safety data exists
• You have a current or past cancer diagnosis, or an unexplained growing lump, given the cancer cases recorded during the 12-week trial and the general caution around growth-hormone-derived compounds
• You are a competitive athlete in a sport that follows the World Anti-Doping Agency code, where growth hormone fragments are prohibited at all times
• You are under 18 or still growing
• You are not working with a physician who knows you are taking it and can monitor you

• Assuming the human evidence supports fat loss. The six trials establish tolerability; they did not produce an approved weight-loss drug, and no peer-reviewed efficacy paper is available to check the marketing claims against.
• Treating it as interchangeable with full growth hormone or with a growth-hormone secretagogue. It does not bind the growth hormone receptor and does not raise IGF-1, so the downstream effects people expect from hGH are not there.
• Reconstituting with tap or spring water, or shaking the vial. Use bacteriostatic water, run it slowly down the side of the vial, and swirl rather than shake so the peptide is not sheared.
• Leaving reconstituted vials at room temperature. Keep lyophilised powder cold and dark, refrigerate after reconstitution, and discard on the timeline your pharmacist gives rather than stretching one vial over months.
• Stacking it with several other unapproved peptides at once, which makes any side effect impossible to attribute and compounds the impurity risk the FDA has flagged for compounded peptide products.