Comparison
TB-500 vs TUDCA
Side-by-side of TB-500 and TUDCA. 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.
TUDCA
TUDCA is the taurine-conjugated form of ursodeoxycholic acid, a bile-acid molecule with replicated effects on liver function, ER stress, and bile flow.
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
TUDCA
- •Bile-acid molecule (taurine-conjugated UDCA) with chemical chaperone activity at the endoplasmic reticulum
- •Established pharmaceutical use for cholestasis and primary biliary cholangitis at 500-750 mg/day
- •Reduces ER stress and stabilizes misfolded proteins; the mechanistic basis for emerging ALS / retinal applications
- •Modest improvements in NAFLD markers and insulin sensitivity at 500-1,750 mg/day in small trials
- •Mitochondrial protection signal in animal models drives the longevity-supplement positioning
- •Generally well-tolerated; mild GI effects are the main dose-dependent issue
Side-by-side
| Attribute | TB-500 | TUDCA |
|---|---|---|
| Category | peptide | supplement |
| Also known as | Thymosin Beta-4 fragment, TB4-Frag, Thymosin Beta 4 | tauroursodeoxycholic acid, taurine-conjugated UDCA |
| Half-life (hr) ↗ | 2 | 4 |
| Typical dose (mg) ↗ | 2.5 | 500 |
| Dosing frequency | 2x weekly (anecdotal protocols) | daily, divided into 2 doses with food |
| Routes | subcutaneous, intramuscular | oral |
| Onset (hr) | - | 1 |
| Peak (hr) | - | 2 |
| Molecular weight | 4963.4 | 499.7 |
| Molecular formula | C212H350N56O78S | C26H45NO6S |
| 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. | Bile-acid signaling via FXR/TGR5 receptors; chemical chaperone reducing ER stress and unfolded protein response; mitochondrial protection through reduced outer-membrane permeabilization. |
| Legal status | Not FDA approved; research-use-only grey market; banned by WADA | OTC dietary supplement (US); pharmaceutical in Italy and several Asian countries |
| WADA status | banned | allowed |
| DEA / Rx | Not FDA approved; not scheduled; research-chemical status | OTC supplement |
| Pregnancy | Insufficient data | Insufficient data for supplement use; UDCA used in cholestasis of pregnancy |
| CAS | 885340-08-9 | 14605-22-2 |
| PubChem CID | 62707662 | 9848818 |
| Wikidata | Q7799921 | Q418751 |
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)
TUDCA
Common side effects
- mild GI upset
- diarrhea (dose-dependent)
- constipation (rare)
- nausea
Contraindications
- complete biliary obstruction
- pregnancy / lactation (insufficient supplement-dose data)
- active GI disease without medical supervision
Interactions
- cyclosporine, oral contraceptives, fat-soluble vitamins: modest absorption changes via altered bile-acid pool(minor)
- phenylbutyrate: synergistic for ALS use (Relyvrio combination); consult clinician(moderate)
Which Should You Take?
TUDCA 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 liver function, pick TUDCA.
- → If your priority is healthspan extension, pick TUDCA.
Edge case: If you want to avoid research-only / gray-market sourcing, TUDCA is the more accessible choice.
Default choice: TUDCA. 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 TUDCA?
TB-500 and TUDCA 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 TUDCA?
TB-500 half-life is 2 hours; TUDCA half-life is 4 hours.
Can you stack TB-500 with TUDCA?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper