TB-500 Dosage in the Research Literature

TB-500 dosage in the preclinical record

TB-500 dosage in the preclinical literature is recorded as what investigators administered to research animals or applied in vitro, not as a human treatment plan. No validated human dosing protocol for the LKKTETQ heptapeptide has been published in the peer-reviewed record. What follows is a digest of the dose-by-species-by-route inventory.

In the rat full-thickness dermal wound model, 5 µg of Tβ4 was applied topically per wound, or 60 µg/kg administered intraperitoneally ^[2]. In the rat medial collateral ligament transection model, 150 µg of Tβ4 was administered intraperitoneally every other day ^[4]. In the murine post-MI cardiac-repair model, 150 µg/g intraperitoneal Tβ4 was used ^[6]. In vitro work — endothelial chemotaxis ^[1], tube formation ^[21], NF-κB suppression in corneal epithelium ^[9] — used ng-to-µg/mL concentrations. The 2003 LKKTETQ-fragment-only study used 5 µg per wound, applied topically in diabetic and aged mice ^[3].

Reported TB-500 dose ranges

Preclinical and equine protocols describe weekly doses in the 2-5 mg range divided across the week rather than daily administration. The equine reference comes from Racing Medication and Testing Consortium bulletins documenting protocols in performance-horse populations; these are not FDA-approved equine indications and the compound is prohibited by every major racing commission ^[16]. In human Phase 1 work, RGN-352 (full-length intravenous Tβ4) was administered as single doses from 42 mg to 1260 mg per subject, with multi-dose escalations ^[14]. No human Phase 1 study has used the LKKTETQ fragment specifically.

TB-500 half-life

The most cited TB-500 half-life numbers come from full-length-Tβ4 IV dosing in healthy volunteers, not from the heptapeptide fragment. In the Ruff 2010 Phase 1 study, plasma half-life of full-length Tβ4 was dose-dependent: approximately 0.95 hours at 42 mg per subject, 1.2 hours at 140 mg, 1.9 hours at 420 mg, and 2.1 hours at 1260 mg ^[14]. Murine intraperitoneal biodistribution showed serum elevation within 2 minutes lasting approximately 40 minutes at a 400 µg dose. Validated human pharmacokinetics for the seven-residue TB-500 fragment have not been published in the peer-reviewed literature. The short circulating half-life of native Tβ4 is cited in the 2025 engineered tandem-Tβ4 paper as a principal limitation driving ongoing peptide-engineering work [recent1].

TB-500 systemic clearance

Anti-doping laboratories report detection windows for TB-500 in days to weeks depending on sample matrix ^[16][19]; pharmacological clearance is substantially faster than the analytical detection window. The Esposito 2012 paper validated an LC-MS detection strategy with sensitivity to 0.02 ng/mL in plasma and 0.01 ng/mL in urine ^[19], confirming that exogenous TB-500 is distinguishable from endogenous Tβ4 at very low concentrations.

TB-500 Administration in Studies

TB-500 injection routes documented in the preclinical record include subcutaneous, intramuscular, intraperitoneal, and intravenous administration, with topical and ophthalmic application reserved for dermal and corneal indications. Choice of route is dictated by the model and endpoint, not by a standardized protocol.

Routes of administration in studies

Preclinical studies report subcutaneous, intramuscular, intraperitoneal, and intravenous administration depending on the model and endpoint. Intraperitoneal is the most common rodent route. Intravenous was used in the human Phase 1 RGN-352 study ^[14]. Topical and ophthalmic application were used in the RGN-259 dry-eye and neurotrophic-keratopathy trials ^[12][13]. Intracardiac injection was used in cardiac-repair studies ^[6].

TB-500 dosing frequency in studies

Most preclinical protocols use 1 to 3 doses per week, not daily. The Xu 2013 MCL study used 150 µg intraperitoneal every other day ^[4]. Equine bulletin protocols describe weekly doses in the 2-5 mg range divided across the week ^[16]. Daily dosing has not been studied in controlled trials of the LKKTETQ fragment in humans, and no validated daily protocol exists in the peer-reviewed record.

TB-500 Cycling Patterns in Reports

TB-500 cycle reports — drawn from anecdotal use logs rather than peer-reviewed trials — describe a 4-6 week loading phase followed by a maintenance or off-cycle period. No validated cycle length exists in peer-reviewed human research. The preclinical studies do not run on cycles; they run on protocol durations dictated by the tissue-repair endpoint (typically 2-4 weeks for dermal models ^[2], longer for ligament and cardiac models ^[4][6]).

Onset of TB-500 effects in studies

Preclinical tendon-healing and dermal-healing studies report measurable histological changes within 2 to 4 weeks of treatment initiation. The Malinda 1999 dermal study measured a 42% increase in re-epithelialization at day 4 and 61% at day 7 ^[2]. The Xu 2013 MCL study measured collagen-fibril diameter changes over the standard rodent ligament-healing window ^[4]. No validated human onset data exist.

Reconstitution in laboratory settings

Lyophilized TB-500 is typically reconstituted with sterile or bacteriostatic water in laboratory protocols, with aqueous solutions refrigerated for stability. These descriptions are laboratory-handling notes from the analytical and preclinical literature; they are not dosing guidance. The 2025 tandem-Tβ4 engineering work specifically cites the short circulating half-life of native peptide as the limitation that motivated structural modification [recent1].