# Epithalon Dosage and Protocol in the Research Literature > Epithalon dosage in published research ranges from 0.1 μg/mouse in rodent carcinogenesis models to 5.0 μg parabulbar in retinitis pigmentosa. Epithalon protocol cycles, routes studied, and pharmacokinetic data — all framed in research context. Published protocols span rodent longevity models, cell-line concentration-response studies, and a clinical parabulbar injection series. All doses described here are from the cited research literature only. ## Epithalon Research Dosage Ranges Published Epithalon dosage varies by study type, species, and endpoint. The [Epithalon dosage in the research literature](/dosage) spans the following documented ranges. In rodent longevity studies: 1.0 μg/mouse subcutaneous, administered on 5 consecutive days per month from age 3 months to death in female SHR mice [4]. In senescence-accelerated SAMP-1 mice, the same monthly protocol used 1 μg/mouse, 5 times per week [14]. In C3H/He female mice, a longer-duration oncostatic protocol used 0.1 μg/mouse, 5 times per week — a 10-fold lower per-administration dose over a more extended schedule [16]. In Drosophila lifespan studies: extremely low dietary concentrations at the larval stage — 0.001 to 5 × 10⁻⁶ wt.% of culture medium — produced 11–16% lifespan extension [3]. The effective concentration range was 16,000–80,000,000 times lower than melatonin for comparable effect. In human cell-line studies: 0.1, 0.2, 0.5, and 1.0 μg/mL in in vitro culture medium across three weeks [2]. In retinal epithelial cell cultures: 20, 40, and 60 ng/mL [15]. In the retinitis pigmentosa clinical series: 5.0 μg parabulbar (para-ocular) injection for 10 consecutive days in 162 patients [8]. This is the only published human dose figure tied to a clinical endpoint and a defined protocol. No standard or consensus Epithalon dosage for humans has been established in any regulatory or peer-reviewed framework. ## Epithalon Protocol The [Epithalon research protocol](/dosage#protocol) used in the most-cited longevity studies follows a monthly cycled schedule: 5 consecutive days of subcutaneous administration per month, beginning in early adulthood and continuing through the lifespan of the animal [4, 14]. This is the Anisimov-group rodent protocol, not a human treatment protocol. The retinitis pigmentosa clinical series used a simpler 10-consecutive-day parabulbar course without cycling [8]. Earlier Epithalamin studies in elderly human subjects used unspecified dosing for neuroendocrine normalization endpoints [6, 7] — precise dose and schedule are not published in those papers. How long is the Epithalon cycle? In the published rodent longevity studies, the cycle is 5 days per month, repeated monthly over the animal's lifespan — effectively continuous cycling [4, 14]. In the retinitis pigmentosa human series, the cycle was a single 10-day consecutive course [8]. The 2025 Araj review notes that Russian-origin commercial protocols often describe 10–20 day cycles repeated 1–2 times per year, but peer-reviewed publication of those specific human schedules is not available [17]. How long does Epithalon take to work in research models? In cell-line studies, telomerase activity and hTERT expression were detectable within days at in vitro concentrations [1, 2]. Circadian normalization effects in animal models appeared within weeks of initiating the protocol [5, 7]. Human timing data outside the retinitis pigmentosa clinical series is not published. ## Routes Studied The documented routes of Epithalon administration in published research are: subcutaneous injection (primary route in rodent longevity and oncostatic studies [4, 14, 16]), parabulbar injection (retinitis pigmentosa clinical series [8]), in vitro culture medium (cell-line studies [1, 2, 15]), and dietary administration in culture medium (Drosophila larval stage [3]). Oral and sublingual routes are discussed in secondary literature and commercial contexts, but no peer-reviewed bioavailability study for oral Epithalon has been published. As a tetrapeptide with a molecular weight of ~390 Da, Epitalon is subject to gastrointestinal proteolysis — enzymatic degradation of short peptides in the digestive tract. Small peptides can in some cases cross intestinal epithelium; the Araj 2025 review notes oral routes are studied but formal bioavailability data are not published [17]. Subcutaneous injection has also been demonstrated to allow membrane penetration and nuclear entry in HeLa cells, which is relevant to the intracellular TERT gene upregulation mechanism [17]. The stability notes from the 2025 review indicate Epitalon contains intramolecular salt bridges that stabilize its structure and that it binds specifically to DNA sequences ATTTG and ATTTC — relevant to telomerase promoter regions. ## Epitalon Half-Life and Pharmacokinetics Formal [Epitalon half-life and pharmacokinetics](/dosage#half-life) data in humans does not exist in the published literature. No validated human pharmacokinetic study has been published. What is the half-life of Epitalon? As a short tetrapeptide (4 amino acids, MW ~390 Da), plasma clearance is expected to be rapid — estimated at approximately 30 minutes in some secondary sources, consistent with the enzymatic degradation kinetics of short peptides. No peer-reviewed measurement of this figure in humans has been published. Two characteristics may complicate the simple fast-clearance picture. First, downstream effects — telomerase gene expression, melatonin normalization — are transcriptional and epigenetic changes that may persist beyond plasma clearance. The TERT upregulation observed in cell lines is a gene-expression change, not a pharmacodynamic effect that requires continuous peptide presence. Second, the DNA-binding specificity of AEDG (to sequences ATTTG and ATTTC in telomerase promoter regions) suggests nuclear localization may extend the effective duration of the peptide's action beyond what plasma half-life alone predicts. In the absence of published pharmacokinetic data, any dose-frequency discussion for humans remains speculative. The rodent protocols (5 days per month [4, 14]) and the retinitis pigmentosa protocol (10 consecutive days [8]) are the only schedules tied to clinical or experimental outcomes in the literature. --- Gilt scrollwork around a twenty-five year literature — the Epithalon record read leaf by leaf, cited to the source, and held by no clinic and no vendor.