TB-500
Also known as Thymosin beta-4 (fragment)
A lab-made piece of thymosin beta-4, a protein involved in wound healing. Sold for injury recovery.
Quick facts
- Status
- Not an approved medicine
- Evidence
- Preclinical (mainly animal studies)
- Taken as
- Injection under the skin
- Common sizes
- 5 mg, 10 mg
- Category
- Tissue repair (experimental)
How it works
Thymosin beta-4 helps cells move to a wound and form new blood vessels. Whether the small fragment does the same in people is unproven.
What people use it for
- Injury recovery
- Flexibility and inflammation
What the research shows
- Animal and lab studies, mostly with the full thymosin beta-4 protein.
- No good human studies of TB-500.
Side effects & risks
- Unknown safety in people
- Theoretical concern about helping abnormal cells grow
- Banned in sport
Is it legal?
Not an approved medicine in the EU, UK or US. In most countries it is illegal to sell it for use in people. Products labelled "research use only" are not checked for quality or purity. Prohibited in sport (WADA).
Storage & safe handling
- Mix with bacteriostatic water: let it run slowly down the inside of the vial and swirl gently — never shake.
- Store the mixed vial in the fridge and follow the use-by period on the label.
- Wipe the vial top with alcohol and use a new sterile needle and syringe every time.
- Rotate injection sites so the same spot is not used again and again.
- Put used needles in a sharps container, not the household bin.
- Get medical help for redness that spreads, fever, swelling or trouble breathing.
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Sources: WADA Prohibited List.
Last updated 12 October 2026. Information — not medical advice. PepTimer does not replace a doctor. Many peptides are not approved medicines in the EU, UK or US. Talk to a qualified healthcare provider before starting, changing or stopping any treatment.
Last updated 12 October 2026. Information — not medical advice. PepTimer does not replace a doctor. Many peptides are not approved medicines in the EU, UK or US. Talk to a qualified healthcare provider before starting, changing or stopping any treatment.