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TB-500 protocol

TB-500 is sold as a lab-made copy of part of thymosin beta-4, a natural protein. We found no published human study of TB-500 itself. The human trials that exist used full-length thymosin beta-4, which is a different product.

No approved medicine contains TB-500Banned in sport (WADA 2026 list, class S2)Full-length thymosin beta-4 has been tested in people (eye drops, vein, heart attack)
ProtocolMixingResultsSide effectsHow it worksSources

The protocol at a glance

There is no human dose for TB-500. For comparison, a phase 1b trial gave full-length thymosin beta-4 by vein once a day for 10 days at 0.5, 2 or 5 mcg per kg to healthy adults.

ItemWhat is known
Human dose of TB-500Not established
Studied inAnimals (TB-500). People have only received full-length thymosin beta-4.
Full-length thymosin beta-4, phase 1b (NCT04555850)0.5, 2 or 5 mcg per kg, daily for 10 days, by vein, in 30 healthy adults
Full-length thymosin beta-4 eye drops, phase 20.1% solution for 28 days, 72 people with dry eye

NCT04555850 tested recombinant human thymosin beta-4 (NL005) from Beijing Northland Biotech; the record posts no results. The eye-drop trial is Sosne 2015. Neither tested TB-500.

Community reports

Community reports commonly describe 2 to 2.5 mg twice a week for 4 to 6 weeks, or 250 to 500 mcg a day. These are user reports, not trial doses.

What people say they do, collected from community discussions. Not tested in a trial; shown so you can compare it with the evidence above.

Mixing

No mixing table here: this one is used as a capsule, nasal spray or skin product, or has no human amount to calculate from. The general mixing calculator works for any vial.

What the trials found

Nothing has been published for TB-500 itself. The closest human results are for full-length thymosin beta-4:

0published human studies of TB-500 found
72people in the dry-eye drop trial; the two main goals were not met
96heart-attack patients given recombinant thymosin beta-4; overall scar size difference was not significant
30healthy adults in the vein safety trial (no results posted)

Sosne G et al. Clin Ophthalmol 2015 (PMID 26056426); Zhang Y et al. Cardiovasc Res 2025 (PMID 41229390); ClinicalTrials.gov NCT04555850. In the heart-attack trial, scar size was smaller only in the 43 people dosed within 8 hours after the procedure.

Side effects

  • There is no side-effect data for TB-500 in people.
  • No adverse events were reported in the 72-person dry-eye trial of full-length thymosin beta-4.
  • Athletes in tested sports cannot use it. The WADA 2026 list names thymosin beta-4 and its derivatives, for example TB-500.

How it works

Natural repair protein (lab data)

Thymosin beta-4 is a natural protein. Lab studies link it to cell movement and tissue repair. Whether TB-500 does the same in people is not known.

Sources

  • ClinicalTrials.gov NCT04555850 (recombinant human thymosin beta-4, phase 1b, healthy volunteers)
  • Sosne G et al. Clin Ophthalmol 2015, PMID 26056426
  • Zhang Y et al. Cardiovasc Res 2025, PMID 41229390
  • Goldstein AL et al. Expert Opin Biol Ther 2012 (thymosin beta-4 review), PMID 22074294
  • WADA Prohibited List 2026, class S2 (thymosin-beta-4 and its derivatives, e.g. TB-500)
  • Drugs@FDA / openFDA search: no thymosin beta-4 product