Stability & potency explained, including when premixed with Cyanocobalamin (B12).
When it comes to preserving the potency and effectiveness of medications like Semaglutide, even when premixed with B12, proper storage is key. But how long does it really last unopened in your fridge, and how much potency are we actually talking about over time?
Unopened and Refrigerated: 120 Days of Stability
For unopened compounded vials of Semaglutide (whether mixed with B12 or not), the standard rule of thumb is up to 120 days of stability when properly stored in the fridge. The recommended temperature range is 36°F to 46°F (2°C to 8°C). At these temperatures, the degradation of the active ingredients remains minimal, allowing the medication to maintain its effectiveness.
Potency Loss: What’s the Real Impact?
So, how much does it actually lose potency over this time? Generally speaking, if you store it correctly and it remains unopened, the loss of potency over the course of 120 days is extremely small—we’re talking 1-2% at most.
If we extend this out to a year of unopened, refrigerated storage, the potential potency loss might reach 5-10%, but it’s rare for patients to keep their medication this long. So for the 120-day period, you can expect the medication to stay near 100% effective.
What Happens If It’s Not Stored Properly?
The biggest risk to the stability and potency of Semaglutide and B12 comes from improper storage, particularly exposure to temperatures outside the recommended range. Leaving it out of the fridge for too long or exposing it to heat can speed up the breakdown of the medication and reduce its effectiveness much more quickly.
B12: Does It Affect Stability?
B12 is a relatively stable compound, so its presence in the mixture doesn’t negatively affect the overall shelf life of the Semaglutide. Whether it’s cyanocobalamin or methylcobalamin, as long as it’s stored properly, B12 will remain stable alongside Semaglutide.
BUD Considerations for Compounded Medications
When dealing with compounded medications like Semaglutide mixed with B12, the Beyond-Use Date (BUD) becomes crucial. According to USP <797> guidelines for Category 2 or Category 3 CSPs (Compounded Sterile Preparations), BUDs can be extended up to 180 days when sterility and stability testing is conducted. For most compounded versions of Semaglutide, however, the more common 120-day stability period applies, especially when stored at the recommended refrigeration temperature.
Final Thoughts on Stability and Potency
In practical terms, you can confidently rely on the potency of unopened Semaglutide with or without B12 for up to 120 days if it’s stored properly. Any potential loss of potency is minimal within that window, so as long as it’s kept refrigerated, you can expect near-full effectiveness throughout this period. After opening, however, it’s a different story—use it within 28 days for the best results.
The takeaway? Store it right, and you’ll get the most out of it. Simple as that.
