Comparison
AOD-9604 vs TB-500
Side-by-side of AOD-9604 and TB-500. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
AOD-9604
AOD 9604 peptide: 16-amino-acid hGH fragment 176-191. Preclinical lipolytic activity, phase 2 obesity trial showed no weight loss vs placebo.
TB-500
TB-500 peptide, a 17-aa thymosin beta-4 fragment. Preclinical tendon and wound healing via actin sequestration. Typical dosage 2 to 5 mg weekly. No human RCTs.
Effects at a glance
AOD-9604
- •Modified 16-amino-acid synthetic fragment of human growth hormone (residues 176-191)
- •Preclinical models show lipolytic activity in adipose tissue without GH-axis growth effects
- •Phase 2 obesity trial (Heffernan 2001) showed no significant weight-loss difference versus placebo
- •Anecdotal protocols use 250 to 500 mcg subcutaneously daily on an empty stomach
- •No FDA approval; the obesity drug development program was discontinued in 2007
- •Granted GRAS status in some jurisdictions for compounded use; not validated for fat loss in humans
TB-500
- •17-amino-acid fragment of endogenous Thymosin Beta-4, an actin-sequestering peptide
- •Preclinical models show accelerated tendon, ligament, and dermal wound healing
- •Equine veterinary use for soft-tissue injury is the most documented real-world application
- •Anecdotal human protocols use 2 to 5 mg twice weekly subcutaneously for 4 to 6 weeks
- •WADA banned under S2 (peptide hormones, growth factors) since 2018
- •No completed phase II or III human RCTs as of 2026; long-term safety unestablished
Side-by-side
| Attribute | AOD-9604 | TB-500 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | hGH fragment 176-191, Human Growth Hormone Fragment 176-191 | Thymosin Beta-4 fragment, TB4-Frag, Thymosin Beta 4 |
| Half-life (hr) ↗ | 0.5 | 2 |
| Typical dose (mg) ↗ | 0.3 | 2.5 |
| Dosing frequency | daily | 2x weekly (anecdotal protocols) |
| Routes | subcutaneous | subcutaneous, intramuscular |
| Onset (hr) | 1 | - |
| Peak (hr) | 2 | - |
| Molecular weight | 1815.17 | 4963.4 |
| Molecular formula | C78H125N23O23S2 | C212H350N56O78S |
| Mechanism | Modified C-terminal fragment of human growth hormone proposed to stimulate beta-3 adrenergic receptor signaling in adipocytes, increasing lipolysis and fatty-acid oxidation without engaging the GH receptor or activating IGF-1. | Sequesters G-actin monomers, modulates cell migration and angiogenesis, and upregulates VEGF and myosin transcription. Promotes endothelial differentiation and stem-cell migration to injury sites in preclinical models. |
| Legal status | Not FDA approved; research-use-only grey market in most jurisdictions | Not FDA approved; research-use-only grey market; banned by WADA |
| WADA status | unknown | banned |
| DEA / Rx | Not FDA approved; not scheduled; research-chemical status | Not FDA approved; not scheduled; research-chemical status |
| Pregnancy | Insufficient data; not recommended | Insufficient data |
| CAS | 221231-10-3 | 885340-08-9 |
| PubChem CID | 71300630 | 62707662 |
| Wikidata | Q4654106 | Q7799921 |
Safety profile
AOD-9604
Common side effects
- injection-site reactions
- transient mild headache (anecdotal)
- minimal in clinical trials
Contraindications
- pregnancy
- lactation
- no established human safety profile for chronic use
Interactions
- beta-blockers: theoretical antagonism of beta-3 adrenergic lipolytic signaling(minor)
TB-500
Common side effects
- injection-site irritation
- fatigue (anecdotal)
- lethargy in early dosing (anecdotal)
Contraindications
- pregnancy
- active malignancy (theoretical angiogenic concern)
- no established human safety profile
Interactions
- BPC-157: Frequently co-administered in anecdotal healing protocols; no controlled interaction data(minor)
Which Should You Take?
TB-500 comes out ahead for most readers on the criteria we weight: 3 catalogued goals, research-only / gray-market sourcing, with a Tier-C outcome catalogued. AOD-9604 is the right call when one of the conditionals below applies.
- → If your priority is fat loss, pick AOD-9604.
- → If your priority is body composition, pick AOD-9604.
- → If your priority is post-training recovery, pick TB-500.
- → If your priority is tendon repair, pick TB-500.
Edge case: Half-lives differ materially (AOD-9604 ~0.5 hr vs TB-500 ~2 hr). TB-500 reaches steady state faster; AOD-9604 is easier to dial in if tolerability is uncertain.
Default choice: TB-500. Wider use case, and broader goal coverage. Reach for AOD-9604 only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between AOD-9604 and TB-500?
AOD-9604 and TB-500 differ in category (peptide vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, AOD-9604 or TB-500?
AOD-9604 half-life is 0.5 hours; TB-500 half-life is 2 hours.
Can you stack AOD-9604 with TB-500?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper