Safety Profile

TB-500 Side Effects & Safety

TB-500 (thymosin beta-4 fragment) has a favorable preclinical safety profile. Human trials are limited to small Phase II populations.

Educational content only. This page is compiled from published research for reference and is not medical advice, diagnosis, or treatment. Readers should verify claims against primary sources and consult a qualified healthcare provider before making any health decisions. Full disclaimer.

Side effects by severity

Common1 effect

Injection site reactions

Mild erythema or discomfort at injection site.

Uncommon3 effects

Fatigue

Reported anecdotally in first weeks of use.

Headache

Typically mild and transient.

Flushing

Reported in early doses.

Rare2 effects

Allergic reactions

Hypersensitivity possible in susceptible individuals.

Nausea

Uncommon and typically mild.

Contraindications

Known hypersensitivity
Active malignancy (angiogenic concern)
Pregnancy and lactation

Drug interactions

Limited data
Theoretical interaction with other tissue-healing or angiogenic agents

Special populations

Not evaluated in pregnancy, pediatrics, or elderly populations. Not FDA approved.

Safety summary

TB-500 has shown good tolerability in limited human trials and no serious toxicity in preclinical models. As with BPC-157, the angiogenic mechanism raises theoretical concerns for use in active malignancy.

Frequently asked

Is TB-500 banned by WADA?

Yes — TB-500 is on the WADA Prohibited List as a growth factor and is prohibited at all times in competitive sport.