Full-length Tβ4 vs the fragment (LKKTETQ) — which is in the vial I'm buying?

N
Joined 2026
25 posts
27d ago · 717 views

Bit of a noob-ish question but I can't find a clear answer. When I buy 'TB-500' from a peptide vendor, am I getting:

  • Full-length Thymosin beta-4 (~43 amino acids, the native peptide)
  • The 17-23 fragment (LKKTETQ, 7 amino acids, the synthetic 'active site' people call TB-500)
  • Something else

Vendor copy is usually vague. Some COAs I've seen specify the fragment. Others just say 'TB-500' with no sequence listed. Should I be insisting on the full-length, or is the fragment the standard community product?

4 Replies

L
Joined 2026
12 posts
26d ago

You're almost certainly getting the fragment. 'TB-500' in community parlance has been the 17-23 fragment (LKKTETQ-style) for a decade. Full-length Tβ4 exists (marketed as Thymosin beta-4) and is way more expensive — different product, different price point. If the vendor is charging fragment prices you're getting a fragment.

H
Joined 2025
205 posts
hexaclinicContributor
26d ago

Ask for a sequence on the COA. If they can't give you one, walk. 'TB-500' is a trade name, not a sequence specification. A real COA lists what's in the vial.

Q2 stack
  • CJC-1295 no DAC · 100 mcg · pre-bed · sub-Q
  • Ipamorelin · 200 mcg · pre-bed · sub-Q
  • BPC-157 · 500 mcg · 2x/day · sub-Q
S
Joined 2026
115 posts
25d ago

Most of the community data, such as it is, is on the fragment. So if you want your experience to map to the forum reports, fragment is what you want. Full-length Tβ4 is a more ambitious purchase with a different literature behind it.

N
Joined 2026
25 posts
24d ago

Clarifying, thanks. Going to ask the vendor for the sequence line on the COA before reordering.

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