Recovery · peptide
TB-500
Synthetic fragment related to Thymosin beta-4
Also sold as: TB500 · Thymosin Beta-4 Fragment · Tβ4 fragment · TB4
A synthetic peptide fragment marketed for tendon, muscle, and soft-tissue healing, sold as a research chemical with essentially no controlled human evidence.
What the evidence says
Graded on the compound profile, not restated here.
TB-500
A synthetic peptide marketed for tendon, muscle, and soft-tissue healing, based on an actin-binding fragment of the natural protein Thymosin beta-4. Sold as a research chemical with essentially no controlled human evidence.
- DPreclinicalTendon and ligament healingSignal in animal models; not demonstrated in humans.
- DPreclinicalMuscle and soft-tissue recoveryPreclinical only.
- DPreclinicalWound healingAnimal and cell data only.
- DPreclinicalCardiac / tissue regenerationPreclinical signal, no human trials of TB-500.
- UUnknownAny long-term safety outcomeUnknown — no controlled human safety data exist.
The single most useful thing to know before buying TB-500 is that it is not Thymosin beta-4, despite being sold under both names.
TB-500 is a synthetic fragment based on the actin-binding region of that protein. Thymosin beta-4 is the full 43-amino-acid human peptide, and it is the one that reached investigational human trials. The fragment has not. Evidence cited for one is routinely used to sell the other.
Every outcome on the TB-500 compound profile is graded D — promising in animals, not demonstrated in humans — or U.
Identity is the check that matters
Fragment products are where substitution is hardest to detect. A purity assay confirms the sample is homogeneous; only mass spectrometry confirms it is the molecule on the label, and the fragment and the full protein have very different masses.
A vendor that publishes HPLC purity but no identity confirmation has answered the easier question.
What “research use only” means for the transaction
The RUO designation is an FDA-defined signal about what testing and oversight you are not getting. It is not a formality, and it is not a legal shield for the seller or the buyer. Sterility in particular is not implied by any purity number.
Before you buy
- Confirm you are buying the fragment, not full-length Thymosin beta-4. Vendors use the names interchangeably; they are different molecules with different literature.
- Require mass-spec identity on a lot-matched COA — fragment products are where identity substitution is easiest to hide.
- Check net peptide content. Vial weight includes counterions and residual solvent.
- Confirm the strength on the COA matches the label, since blend and fragment vials vary between vendors.
What is sold
- Forms
- 2 mg vial · 5 mg vial · 10 mg vial
- Typical price
- $41.99–$74.99 depending on strength Indicative only. Not a live price.
- Storage
- Supplied lyophilized. Once reconstituted, shelf life is set by refrigeration and the preservative in your diluent rather than by how many doses are left.
Last reviewed 2026-08-24.