WWB semaglutide stability test — 12 month update

What about freezing reconstituted sema? I sometimes reconstitute a batch and freeze individual doses in insulin syringes. Does anyone have data on freeze-thaw stability for WWB specifically? I know freeze-thaw cycles are generally bad for proteins but a single freeze of aliquoted doses should be different from repeated cycling.

I didn't test freeze-thaw in this experiment but it's on my list. Anecdotally, I've frozen reconstituted aliquots and used them 2-3 months later with no apparent loss of efficacy, but "apparent" isn't data. In general, semaglutide is fairly robust to a single freeze-thaw cycle. The fatty acid side chain (C18) that gives it albumin-binding properties also provides some structural stability. But repeated freeze-thaw will denature it over time. My recommendation: If you want to aliquot and freeze, do it immediately after reconstitution. Freeze in single-dose amounts to avoid freeze-thaw cycles. Use within 3 months. But if you're going through a vial within a month, just keep it in the fridge — simpler and supported by the data above.

As a healthcare professional, I appreciate the rigor here. One thing I'd add — the type of syringe/needle you use to draw from the vial matters too. Larger gauge needles (18G) create bigger holes in the rubber stopper, potentially allowing more air/contaminant ingress over time vs smaller (29-30G) insulin needles. If you're going to use a vial over 30 days with multiple draws, use the smallest gauge needle practical for drawing your dose. It'll help maintain sterility of the remaining product. Also — always inspect before injecting. If it's cloudy, has particulates, or looks different from when you reconstituted it, discard it. Period. No exceptions. 🏥

Excellent point. I used 29G insulin syringes for all draws in this test, which is what most people would use for subcutaneous injection anyway. Summary of practical recommendations based on this data: 1. ✅ Reconstitute with bacteriostatic water (not sterile water) 2. ✅ Store at 2-8°C (standard refrigerator) 3. ✅ Use within 30 days for best potency (>97.5% maintained) 4. ✅ Use small gauge needles (29-30G) for draws 5. ✅ Inspect visually before each use 6. ❌ Don't leave reconstituted vials at room temperature 7. ❌ Don't use past 45 days even if it looks fine 8. ❌ Don't repeatedly freeze and thaw WWB semaglutide shows excellent stability when handled properly. The product quality holds up. 💪