N-Acetyl Epithalon Amidate Reconstitution Calculator

The base molecular weight of the unmodified Epithalon tetrapeptide is approximately 404.4 g/mol. N‑terminal acetylation (adding an acetyl group, C₂H₃O) and C‑terminal amidation (‑CONH₂ instead of ‑COOH) increase the total weight by roughly 42 g/mol, bringing the modified peptide to about 446.4 g/mol. Your calculator assumes the mass you enter corresponds to the unmodified peptide. If you have a vial labelled “5 mg of N‑Acetyl Epithalon Amidate”, entering 5 mg into the calculator would overestimate the number of active molecules by about 10 % compared to standard Epithalon. Always use the peptide content as stated on the Certificate of Analysis (CoA) for that specific batch.

The peptide works by binding to the G‑rich 3’‑overhang of telomeric DNA and forming a stable G‑quadruplex that blocks telomerase access to the chromosome end. Because a single peptide molecule can induce a conformational change in a large DNA structure, the biological effect saturates at a relatively low concentration, well below the level required to directly inhibit telomerase one‑to‑one. Your calculator will linearly increase the output mass if you double the entered dose, but the G‑quadruplex stabilisation will not double. For DNA‑targeting peptides like this one, the effective concentration may be determined by the stoichiometry of the DNA target, not by free peptide in solution.

The product page for a 10 mg lyophilised N‑Acetyl Epithalon Amidate lists “mannitol” as an excipient, and the Certificate of Analysis shows a purity of over 96 % HPLC. The total mass in the vial is the sum of the active peptide plus the mannitol. The calculator requires you to enter only the active peptide content (e.g., 10 mg, not 10 mg + mannitol). If you mistakenly enter the total fill weight, the calculated concentration will be inflated, and the syringe draw will contain far less active compound than intended. Always check the CoA for the exact active peptide mass and use that value, ignoring the excipient.

The N‑acetyl and C‑terminal amide modifications reduce terminal flexibility and protect both ends of the peptide from enzymatic degradation, resulting in “highly stabilised” behaviour in solution. Standard Epithalon is often reconstituted in separate vials for each 5‑day block to avoid loss of activity. For the modified version, a single vial reconstituted with bacteriostatic water can likely be stored at 4 °C and used for up to 30 days with minimal degradation. Therefore, for a 10‑day cycle, you could reconstitute one vial and use it for the entire study, despite the calculator’s “Doses per vial” number being a pure mathematical count. However, the calculator cannot tell you which storage window applies; you must rely on the chemical stability conferred by the dual modifications.

The calculator assumes a bioavailability of 100 % for subcutaneous injection, which is appropriate for the standard reconstitution method. However, the primary purpose of the N‑acetyl and C‑terminal amide modifications is to improve metabolic stability and absorption, making the peptide more viable for oral delivery. Some suppliers explicitly state that traditional Epithalon is “unstable” when taken orally because it degrades in the stomach, whereas the acetylated/amidated version is engineered for superior bioavailability. If your research protocol administers the peptide orally, you cannot use the calculator’s injection‑derived values without adjusting for the significantly lower bioavailability (even with the modifications). The calculator is a dilution tool for injectable preparations; it does not, and cannot, adjust for route‑specific absorption losses.