TB-500
Healing & recoveryAlso known as: Thymosin Beta-4 fragment, TB4, Tβ4 fragment
A synthetic peptide based on the active part of thymosin beta-4, studied for tissue repair, flexibility, and recovery.
2.What it is / mechanism
TB-500 is built from the active, actin binding region of thymosin beta-4, a natural protein involved in cell movement and repair. It is thought to help cells migrate to injured areas, support new blood vessel growth, and calm inflammation, which may speed healing of muscle, tendon, and other tissue. Like BPC-157, it clears the blood within a few hours, yet its tissue effects are thought to last longer. That is why it is dosed only once or twice a week rather than every day.s1
3.What the evidence supports
- Animal data onlySupports wound healing and soft tissue repair.s1
Repeated animal evidence for thymosin beta-4 and this fragment across many injury models. Direct human trials of the fragment are very limited.
This is full thymosin beta-4, not the TB-500 fragment. The two are often mixed up, so treat claims carefully.
- Anecdotal onlyImproves recovery, flexibility, and injury healing in people.
Popular in the community and in veterinary use, but not shown in human trials of the fragment.
4.Dosing
| Route(s) | subcutaneous (abdomen), intramuscular near the injury |
|---|---|
| Typical range | Loading: about 2 to 2.5 mg twice a week for 4 to 6 weeks. Maintenance: about 2 mg every 1 to 2 weeks. |
| Frequency | Twice weekly during loading, then weekly or every other week |
| Half-life | 2.5 hours |
| Cycle guidance | A 4 to 6 week loading phase, then a lower maintenance dose. |
| Notes | Human dosing comes from community practice, not trials. The circulating is short, only about 2 to 3 hours, so TB-500 does not build up in the blood. The infrequent, twice weekly schedule works because its tissue effects are thought to outlast its time in the blood, not because it accumulates. The plot below shows this: each dose spikes and clears rather than stacking up. |
Saturation plotter
Adjust the protocol to see how TB-500 builds up in the blood over a cycle and whether it reaches a steady-state plateau.
TB-500: Blood level over time
Relative level (mg)Steady-state avg
0.1 mg
Peak / trough
2.5 / 0
Time to ~90% saturation
0.3 d
Saturation at cycle end
100%
Teaching model that assumes even dose spacing, instant absorption, and single compartment clearance. An educational estimate, not a clinical PK simulation or dosing advice.
5.Reconstitution
| Vial sizes | 5 mg, 10 mg |
|---|---|
| Diluent | Bacteriostatic water for multi dose vials, or sterile water for single use |
| Concentration | Example: a 5 mg vial plus 1 mL of water gives 5 mg/mL, so a 2 mg dose is 0.4 mL, which is 40 units on a U-100 syringe. A 10 mg vial plus 2 mL gives the same 5 mg/mL. |
| Notes | TB-500 usually ships as 5 mg or 10 mg freeze dried vials. |
Reconstitution calculator
Pick your vial size and how much water you add to see the draw volume and syringe units for a dose. Open the full calculator →
Inputs
Reminder: 1 mg = 1,000 mcg
Total amount stated on the vial, e.g. 5 mg.
How much diluent you draw into the vial.
Target dose per injection, in mcg. 1 mg = 1,000 mcg.
Result
Draw to
100 units
= 1 mL on your syringe
- Concentration
- 2,500 mcg/mL
- Per unit
- 25 mcg / unit
- Doses per vial
- 2
Educational estimate only. Not medical or dosing advice. Verify every calculation independently before use.
6.Storage & stability
Lyophilized (dry)
| Temp | Freeze for long term storage, or 2 to 8 short term |
|---|---|
| Shelf life | Many months when frozen |
| Notes | Keep dry and out of light until you mix it. |
Reconstituted
| Temp | 2 to 8 (refrigerated) |
|---|---|
| Shelf life | About 2 to 4 weeks |
| Notes | Do not freeze after mixing. Discard if cloudy or discolored. |
7.Reported side effects
- WarningUnknown long term risks, since there is no long term human safety datas3Animal studies have not shown a clear toxic dose, but long term human safety has not been studied.
- CautionInjection site reactions(common)s3
- CautionTemporary tiredness, head fog, or headache(common)s3Most often in the first week of loading, then it tends to fade.
- CautionMild flu like feelings during loading(uncommon)s3
8.Interactions & stacking risks
- InfoBPC-157
Very commonly stacked with BPC-157 for recovery, and combined with it in the GLOW and KLOW blends. No human data supports the combination.
TB-500 promotes cell migration and new blood vessel growth, which in theory could support tumor growth or spread.
9.Contraindications / who should avoid
- SeriousActive or recent cancer, or a strong family history
Its effects on cell migration and new blood vessel growth are a theoretical concern for feeding a tumor. Based on mechanism, not proven human cases, but clinicians advise avoiding it.
- SeriousPregnancy or breastfeeding
No safety data in pregnancy or breastfeeding.
10.COA & purity notes
| Common adulterants | underdosed or mislabeled vials, TB-500 sold as a blend, such as with BPC-157, without clear amounts, confusion between the TB-500 fragment and full thymosin beta-4 |
|---|---|
| Mislabeling | Products vary in what they contain, and a label may not make clear whether it is the TB-500 fragment or the full thymosin beta-4 protein. A recent third party COA helps. |
| Notes | Sold as unregulated research material. TB-500 is also banned in most competitive sports. |
11.Sources
- [s1]Annals of the New York Academy of Sciences (2012). Thymosin beta 4 and tissue repair (review of preclinical work). review
- [s2]ClinicalTrials.gov (2026). TB-500 (Thymosin Beta 4 17-23 Fragment) trial registration. other link
- [s3]Banned Substances Control Group (2026). TB-500: status, risks, and bans in sport. regulatory link
Last reviewed 2026-07-07 · status: reviewed