What is Thymosin beta-4 (full-length)?

The short answer

Thymosin beta-4 is a peptide, a short chain of amino acids.

What it is
Thymosin beta-4 (full-length): Actin-sequestering protein (43-aa).
What people look into
Muscle and exercise, skin and hair

4 sources
Status as of October 4, 2026
How we source
Ellum doesn't sell peptides.

By Ellum EditorialUpdated October 8, 2026AI use

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Peptides: Thymosin beta-4 (full-length) (1 selected) · edit

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What it is

Also known as: tb4, tβ4

Regulatory status

Not FDA-approved How we label status

As of October 4, 2026, Thymosin beta-4 (full-length) is not FDA-approved for any use and is not on FDA's 503A bulks list.

See Thymosin beta-4 (full-length) in the Index →

Federal (FDA): Not FDA-approved
503A compounding: Not listed; not on 216.23 as of 2026-10-07 (as of October 7, 2026)
PCAC history: Not voted; PCAC 2026-07-23 covered the LKKTETQ fragment (TB-500) only
WADA 2026: S2.3

US enforcement actions

1 US enforcement action, in 2026.

Actions by US federal and state agencies whose documents name Thymosin beta-4 (full-length). Each row links to the government's own document.

Scroll sideways to see all columns.

Date	Agency	Action	Document
January 20, 2026	FDA	Warning letter	FDA document, warning letter, January 20, 2026, on fda.gov

References

Sources as of October 4, 2026