TB-500 (5mg)

A synthetic heptapeptide: acetyl-Leu-Lys-Lys-Thr-Glu-Thr-Gln. Esposito's group synthesized that fragment and matched it to material sold as TB-500.^[1]

Full-length thymosin beta-4 is a 43-residue actin-sequestering protein. Older Tβ4 papers describe that protein. They do not automatically describe this vial.^[1][2]

Tβ4 reviews talk about cell migration, angiogenesis, and actin binding. They often point to an actin-binding motif that sits inside the 17-23 stretch.^[2] That is why fragment catalogs and Tβ4 papers end up in the same binder.

Sharing a motif is not identity. If the methods line says thymosin beta-4 and the dominant ion is Ac-LKKTETQ, the paper and the vial have already split.^[1]

No. Steroids are fused-ring lipids. TB-500 is a peptide fragment.^[1] Forum threads that call it a steroid usually also treat full-length Tβ4 and the fragment as one reagent.

Those threads also borrow oral claims from Tβ4 reviews. Published identity work does not give the fragment that exception.^[1][2] Route is a protocol variable you have to validate on the heptapeptide. Pasting a protein paper into a fragment notebook does not finish the job.

Copy a Tβ4 scratch-wound protocol and score closure at 12 hours and 24 hours. The endpoint is still a Tβ4 endpoint from those regenerative-peptide reviews.^[2]

Run the same stock on a mass spec. If the dominant species is the acetylated heptapeptide Esposito described, write Ac-LKKTETQ in the methods.^[1] A 6-hour imaging read can be plating noise. A clean 24-hour plate on the wrong molecule is still the wrong molecule.

BPC-157 is a 15-residue gastric-juice-derived peptide. TB-500 is the acetylated 17-23 Tβ4 fragment.^[1] Both sit in tissue-repair catalogs. The sequences do not match.

The FDA listed thymosin beta-4-related bulk substances among compounding materials that may present significant safety risks.^[3] That is a regulatory flag. For a longer catalog side-by-side, see BPC-157 vs TB-500.

TB-500 peptide for sale and tb-500 price searches treat the trade name as settled. Check whether the Certificate of Analysis sequence and HPLC-MS ions match Ac-LKKTETQ.^[1] Tetrava lists 5 mg and 10 mg lyophilized vials.

A low cart total does not fix a full-length Tβ4 label on a fragment vial. File the FDA compounding safety-risk page next to the lot paperwork.^[3]

Esposito's group was a Ghent anti-doping lab treating TB-500 as an analytical unknown in a product suspected of doping potential.^[1] They synthesized the fragment, then used liquid chromatography-mass spectrometry to show that the sold material matched Ac-LKKTETQ. Characterization. Not a wound-closure trial.

Store sealed lyophilized vials per your peptide SOP. Record lot, operator, and COA file so the fragment identity stays on every plate.