AOD-9604 vs Retatrutide
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Anti-Obesity Drug 9604, Tyr-hGH Fragment 177-191
AOD-9604 is a synthetic fragment of human growth hormone, copying just the last 15 amino acids of the hormone (residues 176 to 191) plus a tyrosine cap. The idea was to keep the fat-burning end of growth hormone while leaving out the part that raises IGF-1 or messes with blood sugar. It was developed by Metabolic Pharmaceuticals in Australia and tested as an anti-obesity drug, but it is not approved by the FDA or any major regulator, and development stopped after it missed its weight-loss targets.
Also: LY3437943, Triple G
Retatrutide is the heavy hitter of the new weight-loss drugs: a once-weekly injectable peptide that hits three receptors at once - GIP, GLP-1, and glucagon - earning it the nickname triple-G agonist. In a phase 2 trial it produced some of the largest weight loss ever recorded for a drug, up to roughly 24 percent of body weight at the top dose. It is investigational, made by Eli Lilly, and not yet FDA approved as of 2026.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | AOD-9604 | Retatrutide |
|---|---|---|
| Category | Weight Loss | Weight Loss |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | In lab and animal studies, AOD-9604 appears to nudge fat cells toward breaking down stored fat (lipolysis) and away from making new fat (lipogenesis), echoing the lipolytic tail-end of the full growth hormone molecule. Unlike real growth hormone, it does this without meaningfully raising IGF-1, the downstream growth signal that drives growth hormone's anabolic and blood-sugar effects. The exact receptor it works through is not pinned down, and a clean, growth-hormone-receptor-independent pathway remains a working hypothesis rather than settled science. In short, the proposed selling point is fat-burning signaling without the classic growth hormone baggage, but the molecular details are still fuzzy. | Retatrutide combines three hormone signals into one molecule. The GLP-1 component curbs appetite and slows stomach emptying, the GIP component supports insulin response and may improve how fat tissue handles nutrients, and the added glucagon receptor activity is the novel piece: glucagon can increase energy expenditure and fat burning in the liver. The idea is that two arms cut how much you eat while the third raises how much you burn, which is why retatrutide is thought to push weight loss further than GLP-1-only drugs like semaglutide or even the dual GIP/GLP-1 agonist tirzepatide. The exact contribution of each receptor in humans is still being worked out, so consider the glucagon-driven energy-expenditure story a strong hypothesis rather than fully nailed down. |
| Common Dosing | 300 mcg daily Once daily, usually morning fasted | 4-12 mg weekly Once weekly, same day each week |
| Administration | Subcutaneous injection or oral (studied both) | Subcutaneous injection weekly |
| Typical Duration | 12-24 weeks in studies | Long-term use expected |
| Best Time to Take | Morning (fasted) | Morning, same day each week |
Possible Side Effects May vary by individual |
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| Research Summary | The animal and cell data look encouraging, but the human story is where it falls apart. Across roughly six randomized, double-blind, placebo-controlled trials involving about 900 people, a safety review published in the Journal of Endocrinology and Metabolism (Moré et al.) found AOD-9604 was well tolerated, did not raise IGF-1, did not harm glucose metabolism, and triggered no detectable antibodies. The catch: it did not deliver clinically meaningful weight loss. The largest Phase IIb obesity trial failed to beat placebo on its main endpoint, and Metabolic Pharmaceuticals halted clinical development around 2007. So the honest summary is a peptide with a clean safety record in humans and essentially no proven efficacy for fat loss in humans. | The key human evidence is the phase 2 trial by Jastreboff and colleagues, published in the New England Journal of Medicine in 2023, which randomized 338 adults with obesity (without type 2 diabetes) over 48 weeks. Mean weight reduction reached about 24 percent at the 12 mg dose, and weight loss had not clearly plateaued by week 48, hinting the ceiling could be even higher. Among participants with prediabetes at baseline, a large majority returned to normal blood sugar. Side effects were dominated by gastrointestinal issues like nausea, vomiting, and diarrhea, the familiar pattern for this drug class, and were mostly dose-dependent. These are genuinely strong phase 2 results, but they are phase 2: larger and longer phase 3 trials are underway to confirm safety and durability, and retatrutide sold outside of trials is not an approved, quality-controlled medicine. |
Frequently Asked Questions: AOD-9604 vs Retatrutide
What is the difference between AOD-9604 and Retatrutide?
AOD-9604 is a weight loss peptide that aod-9604 is a synthetic fragment of human growth hormone, copying just the last 15 amino acids of the hormone (residues 176 to 191) plus a tyrosine cap. the idea was to keep the fat-burning end of growth hormone while leaving out the part that raises igf-1 or messes with blood sugar. it was developed by metabolic pharmaceuticals in australia and tested as an anti-obesity drug, but it is not approved by the fda or any major regulator, and development stopped after it missed its weight-loss targets. Retatrutide is a weight loss peptide that retatrutide is the heavy hitter of the new weight-loss drugs: a once-weekly injectable peptide that hits three receptors at once - gip, glp-1, and glucagon - earning it the nickname triple-g agonist. in a phase 2 trial it produced some of the largest weight loss ever recorded for a drug, up to roughly 24 percent of body weight at the top dose. it is investigational, made by eli lilly, and not yet fda approved as of 2026. The main differences lie in their mechanisms of action and clinical applications.
Which is better, AOD-9604 or Retatrutide?
Neither is universally "better" - the choice depends on your specific goals. AOD-9604 is typically used for weight loss purposes, while Retatrutide is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can AOD-9604 and Retatrutide be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using AOD-9604 and Retatrutide together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.