TB-500 for Dogs
Thymosin beta-4 fragment
The short answer
TB-500 is generally well tolerated in the veterinary literature, with injection-site swelling the most common observation. The decisive safety question is not tolerance but cancer status: because the compound is associated with promoting new blood vessel growth and cell migration, it is contraindicated in dogs with active or suspected malignancy. Screening before starting is not optional. It is also banned in competitive racing and is detectable on testing.
What it is and how it is thought to work
TB-500 is a synthetic fragment of thymosin beta-4, a protein found naturally throughout the body and concentrated at wound sites. The active portion binds actin, the structural protein cells use to move. Research describes this helping repair cells migrate into damaged tissue, alongside new blood vessel formation and collagen laydown.
Mechanism in clinical terms
The LKKTETQ active fragment is associated with actin sequestration, directed cell migration, and wound repair across preclinical models. Investigated for promoting angiogenesis, collagen deposition, and downregulation of inflammatory signalling. Longer functional duration than BPC-157 permits weekly rather than daily administration.
Canine dosing by weight class
Figures below are reported as they appear in the source literature. They are not recommendations, and dosing for an individual dog must be set by a veterinarian.
| Weight class | Reported dose | Frequency | Duration | Studied for |
|---|---|---|---|---|
| Small / toy breedunder 22 lb (10 kg) | 1-2.5 mg per week | Loading 1-2x weekly, then half dose weekly | Loading 2-4 weeks, maintenance 4-8 weeks | Soft tissue injury, wound healing |
| Medium breed22–77 lb (10–35 kg) | 2-5 mg per week | Loading 1-2x weekly, then half dose weekly | Loading 2-4 weeks, maintenance 4-8 weeks | Tendon and ligament injury, mobility, post-surgical recovery |
| Large / giant breedover 77 lb (35 kg) | 5-12 mg per week | Loading 1-2x weekly, then half dose weekly | Loading 2-4 weeks, maintenance 4-8 weeks | Orthopaedic injury, chronic joint disease |
Need a figure for a specific weight? Use the dose calculator, or see the weight-specific pages: small / toy breed, medium breed, large / giant breed.
Contraindications and warnings
Read these before anything else on the page.
⚠ Contraindicated with active cancer
TB-500 is associated with promoting angiogenesis and cell migration in preclinical models — the same two processes tumours depend on to grow and spread. Any dog with a known or suspected malignancy should be screened and cleared before this compound is considered.
Banned in competitive racing
TB-500 is a prohibited substance in racing and is detectable in urine and plasma. Do not administer to any dog competing under an anti-doping authority.
Example research protocol
A representative timeline drawn from the published literature, showing what is monitored and when. Any actual protocol should be set by the veterinarian managing the case.
- 1Weeks 1-2Loading phase
What owners observe
Mild swelling at the injection site is common and settles within a day. Energy and appetite should stay level. Record baseline mobility now — TB-500 improvements are gradual and easy to miss without a reference point.
Clinical monitoring
Full dose 0.1-0.25 mg/kg twice weekly subcutaneously. Document baseline gait score and range of motion. Actin-mediated migration effects are reported to begin within 48 hours in preclinical work.
- 2Weeks 3-4Transition to maintenance
What owners observe
Visible mobility improvement is typical here, with more willingness to play, walk, and climb. If a surface wound is being treated, closure should be visibly accelerating.
Clinical monitoring
Halve the dose and move to once weekly. Reassess gait score. Evaluate collagen deposition and inflammatory resolution at the injury site.
- 3Weeks 5-8Maintenance and taper
What owners observe
Continued gradual improvement, often with better coat quality as a secondary observation. Check injection sites for any persistent lump each time you dose.
Clinical monitoring
Maintain once-weekly dosing. Follow-up imaging around week 6 where applicable. Taper or continue based on response. No withdrawal syndrome has been reported.
What TB-500 is investigated for
Tendon and ligament injury
Strains, partial tears, and chronic tendinopathies in working, sporting, and active dogs.
Cranial cruciate ligament (CCL) tear
Rupture of the stabilising ligament in the stifle, the single most common orthopaedic injury in dogs.
Wound healing
Repair of surgical incisions, lacerations, ulcers, and chronic non-healing wounds.
Post-surgical recovery
Supporting tissue repair, comfort, and return to function after an orthopaedic or soft tissue procedure.
Osteoarthritis
Progressive cartilage loss and joint inflammation, affecting a large share of dogs over eight years old.
Senior dog mobility
The combined effect of arthritis, muscle loss, and reduced activity that limits older dogs.
How it compares
- BPC-157 vs TB-500 for dogs — how TB-500 differs from BPC-157
- TB-500 vs GHK-Cu for dogs — how TB-500 differs from GHK-Cu
- Thymosin Alpha-1 vs TB-500 for dogs — how TB-500 differs from Thymosin Alpha-1
Common questions
Is TB-500 safe for dogs?+
TB-500 is generally well tolerated in the veterinary literature, with injection-site swelling the most common observation. The decisive safety question is not tolerance but cancer status: because the compound is associated with promoting new blood vessel growth and cell migration, it is contraindicated in dogs with active or suspected malignancy. Screening before starting is not optional. It is also banned in competitive racing and is detectable on testing.
How much TB-500 should I give my dog?+
Reported doses vary by weight class. Small / toy breed (under 22 lb (10 kg)): 1-2.5 mg per week, loading 1-2x weekly, then half dose weekly. Medium breed (22–77 lb (10–35 kg)): 2-5 mg per week, loading 1-2x weekly, then half dose weekly. Large / giant breed (over 77 lb (35 kg)): 5-12 mg per week, loading 1-2x weekly, then half dose weekly. These figures are reported as they appear in the source literature and are not recommendations — dosing for an individual dog must be set by a veterinarian who has examined the animal.
How is TB-500 given to dogs?+
TB-500 is administered by subcutaneous injection or intramuscular injection. See the injection guide and reconstitution guide for handling detail.
What is the evidence for TB-500 in dogs?+
TB-500 is graded as emerging evidence on this site, drawing on 5 cited studies. TB-500 is a synthetic fragment of thymosin beta-4, a protein found naturally throughout the body and concentrated at wound sites. The active portion binds actin, the structural protein cells use to move. Research describes this helping repair cells migrate into damaged tissue, alongside new blood vessel formation and collagen laydown.
References
- 1.Kleinman HK, Sosne G Thymosin beta 4 promotes dermal healing: animal studies. Annals of the New York Academy of Sciences, 2010. PMID 20536453
- 2.Goldstein AL, Hannappel E, Sosne G, Kleinman HK Thymosin beta-4: a multi-functional regenerative peptide. Expert Opinion on Biological Therapy, 2012. PMID 22074294
- 3.Kwok WH, et al. Doping control analysis of TB-500 in equine urine and plasma. Journal of Chromatography B, 2013. PMID 23084823
- 4.Esposito S, et al. TB500/TB1000: understanding misbranded drugs. Drug Testing and Analysis, 2022. View source
- 5.CANINE STUDYJournal of the American Holistic Veterinary Medical Association Case report: canine stifle injury managed with BPC-157 and TB-500. JAHVM, 2023. View source
Educational information — not veterinary medical advice
Everything on this page is compiled from published peer-reviewed literature for educational and research purposes. It does not establish a veterinarian-client-patient relationship (VCPR) and is not a substitute for veterinary examination and diagnosis. Most compounds described here are investigational or used off-label and are not FDA-approved for these purposes in dogs. Extralabel drug use in animals requires a valid VCPR and the direct supervision of a licensed veterinarian under AMDUCA (21 U.S.C. §360b). Dosing figures are reported as they appear in the source literature and are not recommendations.