TB-500 side effects and risks

Reported side effects

• Immune or allergic reactions: No reliable human rate for confirmed Ac LKKTETQ. FDA flags peptide impurities and aggregation., serious. Stop use and seek emergency help for breathing trouble, throat swelling or collapse. (source)
• Injection infection or contamination: No compound specific rate. Unauthorized injections can be contaminated or incorrectly labelled., serious. Spreading heat, pain, redness or fever needs prompt medical assessment. (source)
• Long-term effects: No long term human safety study of chemically confirmed fragment was found., serious (source)

Stop and get help if

• Throat or tongue swelling, breathing trouble, collapse: Stop use and call emergency services now.
• Spreading injection-site redness, heat, pain, pus or fever: Stop injections and get urgent same-day assessment. Confusion, fast breathing or fainting needs emergency care.

Who should avoid it

• pregnant: Precaution: fetal safety has not been studied. FDA found no developmental toxicity studies.
• breastfeeding: Precaution: milk transfer and infant effects are unknown.
• tryingToConceive: Precaution: reproductive safety data are missing.
• under18: No pediatric fragment dosing or safety evidence supports self-use.
• activeCancer: Precaution: related repair pathways promote vessel growth. Human cancer risk from the fragment is unknown.
• cancerHistory: Discuss prior cancer before exposure; recurrence risk has not been tested.
• other: A prior serious reaction to this product or its ingredients should stop further exposure.
• kidneyDisease: No human kidney-impairment dosing data exist.
• liverDisease: No human liver-impairment dosing data exist.
• heartCondition: No controlled fragment cardiac safety data establish use in heart disease.
• surgeryPlanned: Tell the surgical team about all peptides; recovery effects and interactions are unproven.
• immunosuppressed: Unregulated injections add infection risk, especially with a weakened immune system.
• bleedingDisorder: Injection-related bleeding is a concern, especially with intramuscular use.
• testedAthlete: WADA 2026 prohibits thymosin-β4 and derivatives, including TB-500, at all times.

Interactions

• Full-length Tβ4 or another TB-500 product: Names overlap. Combining products may duplicate exposure to the same peptide or mix distinct molecules.
• Anticoagulants: Injection-related bruising and bleeding, especially intramuscularly. This is not a proven chemical interaction with TB-500.
• BPC-157 and repair blends: Combination benefits and risks are not established. The dental cases cannot isolate any single drug effect.

Product quality risks

• A 2018 analysis found full-length Tβ4 in all three tested products; two were labelled TB-500. This was a small sample, not a market-wide rate.
• FDA found identity, assay, aggregate and endotoxin testing gaps in example TB-500 certificates.
• Unregulated injections may be contaminated or mislabelled. A purity percentage does not establish sterile contents.