TB-500: research

TB-500 dosage

Typical reported dose: 2.5 mg twice a week

• Reported 2.5 mg twice weekly: 2.5 mg subcutaneously twice weekly twice weekly, under the skin. Reported by users, common report. Studied in: Adults reporting injury-recovery injections. (source)
• Reported daily 700 mcg: 700 mcg subcutaneously each evening once daily, evening, under the skin. Reported by users, occasional report. Studied in: An adult reporting quadriceps tendon pain. (source)
• Reported fragment 500 mcg twice daily: 500 mcg subcutaneously twice daily twice daily, under the skin. Reported by users, rare report. Studied in: An adult who explicitly called the product fragment 17–23. (source)
• Reported loading then less often: 5 mg per week for 4 weeks, then 2.5 mg every 2 weeks after that weekly for 4 weeks; then every 2 weeks, under the skin. Reported by users, occasional report. Studied in: An adult reporting knee pain and subcutaneous thigh injections. (source)
• Reported oral 500 mcg: 500 mcg orally once daily on an empty stomach once daily in the morning, by mouth. Reported by users, rare report. Studied in: A forum commenter describing a capsule plan. (source)

These are doses reported in labels, trials or user reports, not a personal plan. Check the source behind each one.

Work out syringe units with the dosing calculator

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.

How TB-500 works

It copies a short region of thymosin beta-4 involved in cell movement. Results for full-length Tβ4 or the unacetylated fragment cannot be assumed to apply to Ac-LKKTETQ. A lab study found wound-closure activity in one breakdown product, rather than the parent fragment.

• Actin-binding region, residues 17–23: Related to cell movement in lab models; the acetylated fragment has not shown a clear human effect.
• Ac-LKKTE metabolite: Improved fibroblast wound closure in a lab assay; this was not a human wound trial.

Half-life: Human half-life is unknown. Claims of a multi-day half-life are not established by human PK studies.