TB-500 dosage for a small / toy breed
under 22 lb (10 kg)
The short answer
For a dog weighing under 22 lb (10 kg), the dose of TB-500 reported in the literature is 0.2–2.5 mg per week, given weekly total — split into 1-2 injections/week for a 2-4 week loading phase, then about half that weekly total for maintenance, over Loading 2-4 weeks, maintenance 4-8 weeks. It is studied in this weight class primarily for soft tissue injury, wound healing. These figures are reported as published and are not recommendations — the dose for an individual dog must be set by a veterinarian who has examined the animal.
Worked examples at specific weights
Calculated from the reported range of 0.1–0.25 mg per kg of body weight.
| Body weight | Calculated dose range | Frequency |
|---|---|---|
| 2 kg (4 lb) | 0.2–0.5 mg | Weekly TOTAL — split into 1-2 injections/week for a 2-4 week loading phase, then about half that weekly total for maintenance |
| 5 kg (11 lb) | 0.5–1.25 mg | Weekly TOTAL — split into 1-2 injections/week for a 2-4 week loading phase, then about half that weekly total for maintenance |
| 8 kg (18 lb) | 0.8–2 mg | Weekly TOTAL — split into 1-2 injections/week for a 2-4 week loading phase, then about half that weekly total for maintenance |
For an exact figure at your dog's weight, use the dose calculator.
Typical breeds in this weight class
Chihuahua, Yorkshire Terrier, Dachshund, Pomeranian, Shih Tzu and similarly sized dogs generally fall within under 22 lb (10 kg). Weigh your dog rather than estimating — dosing is calculated per kilogram and an estimate that is out by a few kilos changes the figure materially, particularly at the smaller end.
Before dosing at all
⚠ 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.
Common questions
How much TB-500 for a small / toy breed?+
For a dog in the under 22 lb (10 kg) range, the reported dose is 0.2–2.5 mg per week, given weekly total — split into 1-2 injections/week for a 2-4 week loading phase, then about half that weekly total for maintenance, typically for Loading 2-4 weeks, maintenance 4-8 weeks. At a representative weight of 5 kg (about 11 lb), that works out to roughly 0.5–1.25 mg per dose. These figures are reported from the source literature and are not recommendations.
How often should a small / toy breed be given TB-500?+
Weekly TOTAL — split into 1-2 injections/week for a 2-4 week loading phase, then about half that weekly total for maintenance is the reported frequency, over a course of Loading 2-4 weeks, maintenance 4-8 weeks. See the cycling guide for how breaks are structured.
Is TB-500 safe for a small / toy breed?+
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.
References
- 1.Kleinman HK, Sosne G Thymosin β4 Promotes Dermal Healing. Vitamins and Hormones, 2016. PMID 27450738
- 2.Philp D, Kleinman HK Animal studies with thymosin beta, a multifunctional tissue repair and regeneration peptide. Annals of the New York Academy of Sciences, 2010. PMID 20536453
- 3.Goldstein AL, Hannappel E, Sosne G, Kleinman HK Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opinion on Biological Therapy, 2012. PMID 22074294
- 4.Ho EN, Kwok WH, Lau MY, et al. Doping control analysis of TB-500, a synthetic version of an active region of thymosin β4, in equine urine and plasma. Journal of Chromatography A, 2012. PMID 23084823
- 5.Delcourt V, Loup B, Bailly-Chouriberry L, et al. TB500/TB1000 and SGF1000: A scientific approach for a better understanding of misbranded and unapproved drugs. Drug Testing and Analysis, 2023. PMID 36482504
Other weight classes: TB-500 for a medium breed, TB-500 for a large / giant breed.
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.