Reconstitution & Beyond-Use Dating (BUD)

Todd, from a strict regulatory and microbiological standpoint, USP <797> mandates that multi-dose vials containing antimicrobial preservatives (such as 0.9% benzyl alcohol) must be discarded 28 days after initial needle puncture. Here is why that standard exists: Every time a needle pierces the rubber septum, microscopic coring can occur, and room air enters the vial to replace fluid displacement. Over 35 days, repeated punctures introduce ambient microbial exposure and trace oxygen, which oxidizes sensitive peptide bonds and slowly diminishes antimicrobial effectiveness. While the liquid may still look clear, injecting medication beyond the 28-day Beyond-Use Date carries elevated risks of localized subcutaneous injection-site reactions, inflammation, or reduced potency. At Telehealth FX, our compounded programs are structured with fresh 4-week multi-dose shipments delivered automatically every month so you never have to stretch expired vials. You can track beyond-use dating with our [Semaglutide BUD Reconstitution Calculator](/tools/semaglutide-reconstitution-calculator/).