TB-500 Pharmacokinetics
TB-500 half-life, absorption, routes of administration, and clearance.
Half-Life & Dosing Cadence
TB-500 has a reported elimination half-life of ~2-3 days. The half-life is the time it takes for blood levels to fall by half, and it's the single biggest driver of how often you dose. That's why the typical schedule lands around 2x weekly (loading), then 1x weekly at 2–5 mg — frequent enough to keep levels in a useful range without stacking up. Shorter half-lives mean more frequent dosing and faster clearance if you stop; longer ones mean steadier levels but a slower washout.
Administration & Absorption
TB-500 is administered by subcutaneous injection (into the fat layer just under the skin) and intramuscular injection (directly into muscle). The primary route is subcutaneous. Subcutaneous delivery is absorbed steadily from the fat depot, giving smoother peaks than intramuscular dosing. Whichever route you use, rotate sites and follow sterile technique.
Reconstitution & Handling
TB-500 ships as a lyophilized (freeze-dried) powder that you reconstitute before use — a common starting point is a 5 mg vial with 2.5 mL of bacteriostatic water. Add the water slowly down the vial wall, swirl (don't shake), and let it fully dissolve. Reconstituted peptide is refrigerated and used within its stability window; unmixed powder keeps far longer when stored cold and dark. Always confirm exact dosing math against your own vial and concentration.
Onset & Clearance
Because of its ~2-3 days half-life, TB-500 reaches steady levels after a few consistent doses and clears the system within roughly four to five half-lives once you stop. Track how you respond over a defined block rather than judging any single dose, and give the compound enough consistent days before deciding whether it's working. This is educational information, not medical advice — review your protocol with a clinician.
Physicochemical and PK profile
- Molecular Formula
- C212H350N56O78S
- Molecular Weight
- 4963.44 g/mol
- CAS Number
- 77591-33-4
- Half-Life
- ~30–60 min (Thymosin Beta-4 in rodent plasma models); TB-500 synthetic fragment not independently characterized by published PK study
- Sequence
- Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES
- Solubility
- Soluble in water and bacteriostatic water
- Storage
- Store lyophilized powder at -20°C protected from light. Reconstituted solution at 4°C.
References
- Thymosin beta4 and tissue regeneration · Goldstein AL, et al. · 2012
- Goldstein AL, Kleinman HK. Minireview: Crosstalk between thymosin β4 and the chemokine network. Ann N Y Acad Sci. 2015. · Martinez JO, Evangelopoulos M, Bhavane R, Acciardo S, Salvatore F, Liu X, Ferrari M, Tasciotti E · 2015
- Thymosin β4 Promotes Dermal Healing. · Kleinman HK, Sosne G · 2016
- Gene ResultTMSB4X thymosin beta 4 X-linked [ (human)] - NCBI
- Philp D, Kleinman HK. Animal studies with thymosin β4, a multifunctional tissue repair and regeneration peptide. Ann N Y Acad Sci. 2012. · Meyer M, Elmer S, Jäncke L · 2012
- Intra-Articular Injection of BPC 157 for Multiple Types of Knee Pain. · Lee E, Padgett B · 2021
- Biological activities of thymosin beta4 defined by active sites in short ... · Sosne G, Qiu P, Goldstein AL, Wheater M · 2010
- Malinda KM, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999. · Pinto B, Pierotti R, Canale G, Reali D · 1999
- Identification of glutamine as a potential therapeutic target in dry eye disease. · Chen X, Zhang C, Peng F et al. · 2025
- Thymosin Beta-4 - an overview | ScienceDirect Topics
- Smart N, et al. Thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization. Nature. 2007. · Lindholm P, Voutilainen MH, Laurén J, Peränen J, Leppänen VM, Andressoo JO, Lindahl M, Janhunen S, Kalkkinen N, Timmusk T, Tuominen RK, Saarma M · 2007
- Thymosin beta-4 denotes new directions towards developing prosperous anti-aging regenerative therapies. · Bock-Marquette I, Maar K, Maar S et al. · 2023