AOD-9604 and retatrutide were both built to treat obesity, twenty years apart. AOD-9604, a fragment of human growth hormone, went through a sponsor's trial programme in Australia in the early 2000s, was given by mouth and by vein, and was dropped for obesity in 2007; it survives on the research market as an injection nobody tested. Retatrutide is a weekly injection from Eli Lilly that acts on three metabolic receptors and has published phase 2 and phase 3 weight results. Both are sold in research vials and compared online. This page sets the two records side by side (sources opened 2026-10-26) and converts the figures into syringe units. It reports figures; it suggests none.
The single-compound records are on AOD-9604 dosage and retatrutide dosage. Vial arithmetic for any volume is in the calculators for AOD-9604 and retatrutide.
Side by side
| AOD-9604 | Retatrutide | |
|---|---|---|
| What it is | Growth hormone residues 177–191 plus an N-terminal tyrosine | Single peptide agonist at GIP, GLP-1 and glucagon receptors |
| Developer and years | Metabolic Pharmaceuticals, trials 2001–2006 | Eli Lilly, phase 2 published 2023, phase 3 reporting 2026 |
| Status | Obesity development stopped February 2007; no label | Investigational; application planned for Q1 2027 |
| Human dose record | Oral 0.25–54 mg; IV 25–400 mcg/kg; 893 subjects | 1–12 mg SC weekly; 338 in phase 2, 2,335 enrolled in TRIUMPH-1 |
| Published weight result | Not in the trial summary | −24.2% at 48 weeks on 12 mg (phase 2); −28.3% at 80 weeks (TRIUMPH-1) |
| ClinicalTrials.gov / PubMed, 2026-10-26 | 0 / 23 | 34 / 207 |
| Circulating figure (2026-09-18) | 250–500 mcg SC daily, often 300 mcg | 0.25–4 mg weekly, below the trials' first step |
| Research vials | 2, 5, 10 mg | 5, 10, 20 mg |
The two records are almost mirror images. AOD-9604 has human trials but by routes nobody now uses, and no published weight result; retatrutide has the published weight results and the route people use, but no approval and no research-market figure that matches its trials.
What each record holds
AOD-9604. The sponsor's six double-blind placebo-controlled trials comprised two intravenous studies (single infusions of 25 to 400 mcg/kg in 15 healthy men and 25 to 100 mcg/kg in 23 obese men) and four oral studies, the largest giving 0.25, 0.5 or 1 mg tablets daily for 24 weeks to 502 adults. The 2013 summary reports that IGF-1 did not change at any dose and glucose tolerance did not worsen, and does not report weight. The fragment's fat-metabolism claim rests on rat work, including 500 mcg/kg by mouth for 19 days (Ng et al., Horm Res 2000, PMID 11146367). It is named in section S2.2.3 of the 2026 World Anti-Doping Agency Prohibited List, among growth hormone fragments (as recorded on this site's AOD-9604 vs MOTS-c page, read 2026-10-17).
Retatrutide. The phase 2 abstract, read tonight, describes six arms against placebo in adults with a BMI of 30 or more, or 27 to 30 with a weight-related condition; at 48 weeks 83% on 12 mg had lost 15% or more of body weight, against 2% on placebo. Gastrointestinal events were the most common, dose-related and partly reduced by a 2 mg rather than 4 mg starting dose, and heart rate rose with dose, peaking at 24 weeks. Lilly's TRIUMPH releases, recorded on this site's retatrutide page, report the phase 3 results; the escalation ladder is on the retatrutide dose schedule page.
The arithmetic of a week
| AOD-9604 (circulating) | Retatrutide (trials) | |
|---|---|---|
| Per injection | 250–500 mcg | 1–12 mg |
| Injections per week | 7 | 1 |
| Weekly mass | 1.75–3.5 mg | 1–12 mg |
A daily 300 mcg of AOD-9604 adds up to 2.1 mg a week, the same mass as retatrutide's 2 mg starting step. The coincidence means nothing pharmacologically: the two molecules act on unrelated targets, AOD-9604's injected figure has no trial behind it, and retatrutide's 2 mg is a starting step in an escalation, not a maintenance dose.
Units per draw
Units on a U-100 syringe = milligrams ÷ concentration in mg/mL × 100.
| Amount | 10 mg/mL | 5 mg/mL | 2.5 mg/mL | 2 mg/mL |
|---|---|---|---|---|
| 250 mcg (AOD-9604) | 2.5 units | 5 units | 10 units | 12.5 units |
| 300 mcg (AOD-9604) | 3 | 6 | 12 | 15 |
| 500 mcg (AOD-9604) | 5 | 10 | 20 | 25 |
| 2 mg (retatrutide first step) | 20 | 40 | 80 | 100 |
| 4 mg (retatrutide) | 40 | 80 | 160 (more than one syringe) | 200 |
| 12 mg (retatrutide) | 120 (more than one syringe) | 240 | 480 | 600 |
Where the concentrations come from: 10 mg/mL is a 10 mg vial with 1 mL of water or a 20 mg vial with 2 mL; 5 mg/mL a 5 mg vial with 1 mL or a 10 mg vial with 2 mL; 2.5 mg/mL a 5 mg vial with 2 mL; 2 mg/mL a 2 mg AOD-9604 vial with 1 mL. The scales barely overlap: AOD-9604's figures are small draws at any concentration, retatrutide's trial doses fill or overflow a syringe unless the vial is concentrated. Mixing figures are on AOD-9604 reconstitution and retatrutide reconstitution; per-dose retatrutide tables are on retatrutide units, and AOD-9604 against another weight-loss compound is on AOD-9604 vs tesamorelin.
What is not established
No study has compared AOD-9604 with retatrutide or given them together. AOD-9604 has no published human weight result and no human data by injection; retatrutide has no approved dose, and the figures circulating for research vials sit below every trial's first step. Medibact's AOD-9604 guide and retatrutide guide cover the compounds. Decisions about administering anything belong with a clinician.
Sources and dates
Opened 2026-10-26: the abstract of Jastreboff et al. 2023 (PMID 37366315) through NCBI E-utilities, and the PubMed record of Ng et al. 2000 (PMID 11146367); ClinicalTrials.gov v2 API searches for retatrutide (34), AOD-9604 and AOD9604 (0 each); PubMed counts for retatrutide (207), AOD-9604 or AOD9604 (23) and both (0); DailyMed search for aod-9604 (0); PubChem CID 71300630. From this site's pages with their read dates: the Stier, Vos and Kenley 2013 trial summary and vendor figures (2026-09-18), Lilly's TRIUMPH releases, enrolment and submission plan (2026-09-18), the end of AOD-9604's obesity programme (site compound notes), the Prohibited List section (2026-10-17). Unit arithmetic by this site. Corrections go to the contact page.