TB-500 Guide: Reported Doses and the Evidence

What TB-500 is

Doping-control researchers in a 2012 paper describe TB-500 as a veterinary preparation whose key ingredient is LKKTETQ, residues 17 to 23 of thymosin beta-4, with the N-terminus acetylated. That segment is the actin-binding region of the protein. TB-500 is therefore not full thymosin beta-4, and some vendors sell the full protein under the same name. The two are different molecules at very different doses, so a result in one does not carry over to the other.

Two points follow. The only controlled human data are for thymosin beta-4, at intravenous doses far larger than the milligram doses people inject (the abstract reports 42 to 1,260 mg), and none of it concerns tendon or muscle recovery. And the TB-500 work we found concerns horse doping detection. Claims of tissue healing in people rest on animal wound models and on extrapolation. For how this compares with the other recovery peptide, see TB-500 vs BPC-157 and the BPC-157 guide.

TB-500 dosage

Nobody has run a dose-finding trial of TB-500 for recovery. The schedule below is what circulates, laid out so you can see how much of it is convention. It is reported practice and not a recommendation.

Sourcing the vial for these numbers? Our top pick is Amino Club (Code 100); the comparison is on best place to buy TB-500. Laboratory research use only, not for human use. Affiliate link.

The loading idea is that repeated doses build up in tissue, and the weekly schedule rests on the same argument. No published human study compares a loaded protocol with a flat one, so treat both as convention. Some reports scale by bodyweight, but that is arithmetic applied to an unvalidated number. Block length and spacing are covered in peptides for tendon repair and recovery peptides.

Syringe units for 2 mg, 5 mg and 10 mg vials

A U-100 insulin syringe has 100 units per millilitre. Units equal dose in mg divided by concentration in mg/mL, times 100. The 2 mg and 5 mg dose columns are arithmetic for the figures in the table above.

Because TB-500 is dosed in milligrams, a 5 mg draw from a dilute vial can overflow a 1 mL syringe, which is why the smaller water volumes are easier. Mixing a milligram dose up with the microgram doses used for BPC-157 is the common error. Pair this with the TB-500 dosage calculator, and store reconstituted vials refrigerated; the peptide storage guide covers shelf life.

Running it with BPC-157

The pairing is popular because the two are described as local and systemic. BPC-157 is reported at 250 to 500 mcg daily and TB-500 at 2 to 5 mg twice weekly. No study has tested the combination in people. Dose and unit details for the other half are on the BPC-157 dosage page, and the stack builder lays out timing.

Safety, sport and quality

In the 2010 volunteer study of intravenous thymosin beta-4, adverse events were infrequent and mild or moderate, with no serious events over 14 days. That does not establish safety for TB-500 or for months of use. TB-500 is claimed to promote angiogenesis, so active cancer is a theoretical concern, not a demonstrated harm. Reported side effects from users are covered in TB-500 side effects.

The World Anti-Doping Agency's Prohibited List names thymosin-beta-4 and its derivatives, with TB-500 as an example. Product identity is the other risk: because vendors sell both the fragment and the full protein as TB-500, ask for a third-party certificate of analysis that names the sequence and matches the lot number on the vial. Vendors we list with batch testing include Apollo Peptide Sciences, Pantheon Peptides, Amino Club and Ascension Peptides; see the vendor scorecard.

Frequently asked questions

What is the TB-500 dosage?

There is no established human dose. The protocol people report is 2 to 5 mg subcutaneously twice weekly for 4 to 6 weeks, then 2 to 5 mg once weekly, and it comes from community practice, not a trial. The human studies we found used thymosin beta-4 itself intravenously, at 42 to 1,260 mg per dose.

Is TB-500 the same as thymosin beta-4?

No. Doping-control researchers describe TB-500 as N-acetylated LKKTETQ, the seven-amino-acid segment at positions 17 to 23 of thymosin beta-4, sold as a veterinary preparation. The trials in people tested synthetic thymosin beta-4, which is the whole protein.

How many units is 2 mg of TB-500 on an insulin syringe?

It depends on the vial and water. A 5 mg vial with 2 mL of water is 2.5 mg/mL, so 2 mg is 0.8 mL, or 80 units on a U-100 syringe. A 10 mg vial with 2 mL is 5 mg/mL, so 2 mg is 40 units.

Has TB-500 been tested in people?

We found no published human trial of TB-500 itself. Thymosin beta-4 has been tested in healthy volunteers, where intravenous doses of 42 to 1,260 mg a day for 14 days were well tolerated, and in two phase 2 trials of leg and pressure ulcers. TB-500 has been studied in horses for doping detection.

Is TB-500 banned in sport?

Yes. The World Anti-Doping Agency's Prohibited List names thymosin-beta-4 and its derivatives, with TB-500 given as an example. The list is reissued each year, so check the current edition before competing.

Sources

1. Ho et al, doping control analysis of TB-500, a synthetic version of an active region of thymosin beta-4, in equine urine and plasma, J Chromatogr A, 2012
2. Ruff et al, a randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta-4 in healthy volunteers, Ann N Y Acad Sci, 2010
3. Treadwell et al, the regenerative peptide thymosin beta-4 accelerates the rate of dermal healing in preclinical animal models and in patients, Ann N Y Acad Sci, 2012
4. World Anti-Doping Agency, The Prohibited List
5. ClinicalTrials.gov NCT00832091, study of thymosin beta-4 in patients with venous stasis ulcers

The literature on TB-500 itself is thin, so these five sources are everything we relied on. We found no human trial of TB-500, and the community figures above have no published source.