Comparison
TB-500 vs Urolithin A
Side-by-side of TB-500 and Urolithin A. 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.
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.
Urolithin A
Urolithin A supplement guide: pomegranate-derived metabolite, 500-1000 mg Mitopure dosing, mitophagy and muscle endurance evidence.
Effects at a glance
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
Urolithin A
- •Gut-microbiome-derived metabolite of pomegranate and walnut ellagitannins
- •Roughly 40% of adults are 'urolithin producers' from dietary intake; ~60% are non-producers
- •Ryu 2016 (Nature Medicine) reported lifespan extension in C. elegans and muscle benefits in aged rodents
- •Andreux 2019 first-in-human trial (n=60) established safety and mitochondrial gene-expression upregulation
- •Singh 2022 (n=66, 4 months, 1000 mg/day) reported improved muscle endurance in older adults
- •Most human trial portfolio is Amazentis-funded; independent replication is thin
Side-by-side
| Attribute | TB-500 | Urolithin A |
|---|---|---|
| Category | peptide | supplement |
| Also known as | Thymosin Beta-4 fragment, TB4-Frag, Thymosin Beta 4 | UA, Mitopure, ellagitannin metabolite |
| Half-life (hr) ↗ | 2 | 17 |
| Typical dose (mg) ↗ | 2.5 | 500 |
| Dosing frequency | 2x weekly (anecdotal protocols) | daily, morning with food |
| Routes | subcutaneous, intramuscular | oral |
| Onset (hr) | - | 2 |
| Peak (hr) | - | 4 |
| Molecular weight | 4963.4 | 228.2 |
| Molecular formula | C212H350N56O78S | C13H8O4 |
| Mechanism | 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. | Induces mitophagy via potentiation of PINK1/Parkin signaling, leading to selective degradation of damaged mitochondria. Secondary anti-inflammatory effects via NF-kB modulation. |
| Legal status | Not FDA approved; research-use-only grey market; banned by WADA | OTC dietary supplement (US GRAS 2018; EFSA Novel Food 2021) |
| WADA status | banned | allowed |
| DEA / Rx | Not FDA approved; not scheduled; research-chemical status | OTC supplement (not scheduled) |
| Pregnancy | Insufficient data | Insufficient data; not routinely recommended |
| CAS | 885340-08-9 | 1143-70-0 |
| PubChem CID | 62707662 | 5488186 |
| Wikidata | Q7799921 | Q27101321 |
Safety profile
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)
Urolithin A
Common side effects
- mild GI upset (rare)
- soft stools (rare)
Contraindications
- pregnancy and lactation (insufficient data)
- active chemotherapy (consult oncology)
Interactions
- chemotherapy agents: theoretical interaction with mitochondrial-targeting agents; consult oncologist(moderate)
Which Should You Take?
Urolithin A comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. TB-500 is the right call when one of the conditionals below applies.
- → If your priority is post-training recovery, pick TB-500.
- → If your priority is tendon repair, pick TB-500.
- → If your priority is healthspan extension, pick Urolithin A.
- → If your priority is muscle hypertrophy, pick Urolithin A.
Edge case: If you want to avoid research-only / gray-market sourcing, Urolithin A is the more accessible choice.
Default choice: Urolithin A. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for TB-500 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 TB-500 and Urolithin A?
TB-500 and Urolithin A differ in category (peptide vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, TB-500 or Urolithin A?
TB-500 half-life is 2 hours; Urolithin A half-life is 17 hours.
Can you stack TB-500 with Urolithin A?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper