Tissue Repair
TB-500
Thymosin Beta-4 fragment
Chases the same goal as BPC-157, helping the body heal, but works throughout the body rather than at one injury site, which is why the two often get used together. Same evidence gap too: animals only, no human trials.
Synthetic Ac-LKKTETQ fragment of thymosin beta-4. Direct human efficacy, safety and pharmacokinetic evidence for the exact TB-500 fragment has not been established.
How well studied
Tier Guide: A = Well studied, B = Some good studies, C = Early evidence & D = Barely studied
Little to no real testing in humans at all. Mostly theory, lab results, or anecdote.
UK status
How you could legitimately come across it here, if at all
The UK position is genuinely unsettled or disputed in our own notes, so we are not going to state it as fact either way.
Evidence strength and UK regulatory status answer different questions.
Heightened caution: this compound carries unresolved regulatory, safety or supply-chain concerns in the UK. Nothing here is a recommendation to use it.
Overview
How it works
Rather than working in one spot, this helps repair cells travel to wherever they're needed around the body. That's the main difference from BPC-157.
TB-500 contains the acetylated LKKTETQ motif from residues 17-23 of thymosin beta-4. Biological claims are largely extrapolated from the parent protein or preclinical fragment work.
Reported benefits
- Preclinical work around the LKKTETQ motif and full-length thymosin beta-4 is relevant context
- Direct human clinical benefit for the exact TB-500 fragment has not been established
Who it's typically used for
Timeline to results
Safety & UK access
Dosage
No established human dose for the Ac-LKKTETQ fragment sold as TB-500. Trials of full-length thymosin beta-4 are a different molecule and are not a dosing basis for this one.
Side effects
- Injection site reactionsreported anecdotally; no human trial of this fragment exists
- Dizzinessreported anecdotally
- Nauseareported anecdotally
- Sourcing purityunverified across grey-market supply
Getting it in the UK
The UK position is genuinely unsettled or disputed in our own notes, so we are not going to state it as fact either way.
Where it turns up
- Specialist unlicensed supply
- Unregulated online market
- Not routinely available in the UK
Not authorised as a UK medicine, and the regulatory picture is actively contested: our notes record ongoing regulator scrutiny of clinics supplying it. We are not stating whether it can be lawfully supplied to you. Most online supply sits outside any regulated system.
Not MHRA-licensed; some UK private clinics prescribe via the unlicensed-medicines route, same regulatory scrutiny context as BPC-157
MHRA: the UK regulator that assesses whether a medicine is safe and works before it can be authorised for use here. Something not being MHRA-licensed does not automatically mean it is illegal, and it does not mean it is safe.
This is background information about UK regulation, not advice about what you can or should obtain.
Evidence & sources
Why this rating?
The A to D rating shown above comes from our earlier editorial review and is still waiting to be migrated into the structured review record below. That is a gap in our record-keeping, not a sign the rating is wrong.
Evidence fingerprint
No route and indication scope has been published for this profile yet, so no fingerprint is shown.
Sources
Structured source audit not yet published for this profile. The references behind this page are being catalogued one compound at a time, and this one has not been through that process yet.
Content freshness
- Last reviewed
- 24 Sept 2026
- Regulatory status last checked
- 21 Aug 2026