Storing Epithalon: Best Practices

❄️ Lyophilized Powder Storage

Store Epithalon (Epitalon) lyophilized powder at -20°C in a sealed container, protected from light and moisture. Under these conditions, the peptide is stable for several years. For long-term archival storage, -80°C is recommended. Keep vials desiccated; the tetrapeptide Ala-Glu-Asp-Gly is hygroscopic and will absorb atmospheric moisture if exposed.

🧪 Reconstituted Solution Storage

After reconstitution, store at 4°C (refrigerator temperature). Reconstituted Epithalon is stable for approximately 2–20 days depending on solvent and conditions. Bacteriostatic water extends working solution stability. Prepare aliquots of stock solution to avoid repeated freeze-thaw cycles, which accelerate degradation.

⚗️ Reconstitution Notes

Epithalon is water-soluble as the free peptide. If supplied as the TFA (trifluoroacetic acid) salt, the TFA counterion contributes to the mass — net peptide content is lower than the stated weight. If supplied as the acetate salt, net peptide content is higher. Reconstitute with sterile water or bacteriostatic water. Typical research concentrations: 1–5 mg/mL in aqueous solution.

⚠️ Degradation Pathway

The N-terminal glutamic acid (Glu) residue in the AEDG sequence can cyclize to pyroglutamate, a spontaneous non-enzymatic degradation pathway. This reaction is accelerated by heat and repeated freeze-thaw cycles. Storage at -20°C and prompt use after reconstitution minimizes this pathway. Purity verification should be performed by RP-HPLC and mass spectrometry before use.

💉 Administration Forms Studied

Peer-reviewed research has investigated Epithalon via multiple administration routes, including subcutaneous injection, intramuscular injection, parabulbar (periocular) injection for retina studies, sublingual, oral, and intranasal delivery. Route selection in research protocols significantly affects bioavailability and tissue distribution.