TB-500
Also called Thymosin Beta-4 fragment
What to know about TB-500
TB-500 is a marketed name generally associated with a short thymosin-beta-4-related fragment. Much of the cited literature instead studies full-length thymosin beta 4, so the substances should not be treated as interchangeable.
- How it may work
- Full-length thymosin beta 4 binds actin and has been studied for cell migration, blood-vessel growth, and tissue-remodelling signals. Evidence for a short TB-500 fragment is much thinner.
- What research found
- Animal work with full-length thymosin beta 4 reported faster dermal repair. That does not directly establish outcomes for commercial TB-500 material or in humans.
- What is not settled
- Identity, purity, human exposure, immune reactions, and long-term safety for TB-500 products are poorly characterized.
- Research and product status
- TB-500 is not a licensed U.S. medicine. WADA prohibits thymosin beta 4 and derivatives in sport.
Research reference
- Research amount range
- 2–5 mg per administration — not a starting amount
- Reference frequency
- 2x per week — catalogue input, not a personal schedule
- Evidence route
- No human administration route established by this catalogue's evidence tier.
- Reported timing context
- Commonly run as a twice-weekly loading period, then less often.
- What people report
- Reports describe a gradual timeline over weeks rather than days.
- Model accumulation timescale
- ~12.5 days — about five half-lives with regular repeated exposure; not time to a result
- Storage
- Storage and in-use limits depend on the exact formulation and packaging. A compound name alone cannot establish temperature, diluent, or shelf life. Details
- Reported course context
- 4–6 loading weeks
- Reported break context
- 2–4 weeks Why
A research and community reference, not medical advice. Figures are descriptive, vary between sources, and are not a recommendation for use.
When results may show
- When change was measured
- The commonly cited repair literature studied full-length thymosin beta 4, often in animal models, rather than confirming a human time-to-result for the short material commonly sold as TB-500.
- When to assess
- There is no direct human outcome study that validates a loading period or a week at which TB-500 should be judged. Timelines borrowed from full-length thymosin beta 4 are not interchangeable evidence.
- Conditions and limitations
- No study establishes that local injection, exercise timing, or pairing with BPC-157 is required. A marketed fragment and full-length thymosin beta 4 can differ in identity, exposure, and effect.
- When to stop
- No human target, maintenance schedule, or evidence-based quit rule has been established for TB-500. Lack of change is not evidence that a longer or larger course will work.
Research timing is descriptive, not a promise or personal instruction. A severe or persistent reaction needs prompt clinical review. This is not medical advice.
Combination evidence and cautions
What is known and unknown about TB-500 alongside other compounds or medicines.
Key properties
- Formula
- C212H350N56O78S
- Mol. weight
- 4,963.4 Da
- CAS
- 77591-33-4
- PubChem CID
- 45382195
External references
Structure note
A diagram is a reference representation of the named chemical structure. It does not establish the composition, purity, or identity of any particular vial.
Estimates for the parent protein; fragment data is thin.
Human pharmacokinetics for the fragment are thin and no trial fixes an injected schedule; circulating amounts are community-derived, so no schedule table is shown.
Modelled level — 2x per week
1× is the peak after a single dose.
- Steady-state peak
- 1.65× single dose
- Time to steady state
- 12.5days
- Administrations
- 2/ week
Read off the modelled curve, not an even-interval formula
About five half-lives
Where these numbers come from
- Thymosin β4 preclinical repair literatureThe fragment's human pharmacokinetics are thin; figures derive from the parent protein and community-reported use.