Cold-Chain Shipping & Temperature Stability Study

Why do my vials sometimes arrive warm?

Two reasons, both of them normal:

1. Phase-change cold packs are designed to melt. They absorb thermal energy while melting and that's what keeps your vial cool. By the time they're fully melted, they've already done their job — they kept the vial below the upper safe limit for the entire transit window.
2. Ground carriers add transit time. Even with overnight shipping, customs, weekend layovers, and "out-for-delivery" sitting on a truck all add hours. We size our cold packs to cover the worst-case 7-day scenario, but on a normal 2-3 day transit your packs may be fully melted by day 2.

The reason this isn't a problem is the active ingredient in your vial: both semaglutide and tirzepatide are remarkably thermally stable. The FDA-approved branded versions (Ozempic, Wegovy, Mounjaro, Zepbound) all list official room-temperature storage allowances of up to 21-56 days at temperatures up to 86 °F. Our compounded versions use the same active molecule and follow the same physical-chemistry rules.

Methodology

Independent third-party laboratory analysis was performed on sealed compounded Semaglutide-with-B12 and Tirzepatide-with-B12 vials shipped via standard ground carriers in insulated foam shippers with two phase-change cold packs. Vials were exposed to the following temperature excursions before assay:

• 72 hours at 25 °C (77 °F) — typical 2-3 day ground shipping
• 168 hours (7 days) at 30 °C (86 °F) — worst-case summer transit including weekend layover
• 4 thermal cycles between 4 °C and 30 °C — simulating multi-stop courier handling

Post-excursion samples were assayed for active pharmaceutical ingredient (API) potency by HPLC, sterility (USP <71>), endotoxin levels (USP <85>), pH, and visual inspection.

Results

• API potency: 99.4% – 100.7% of label claim across all conditions, well within USP acceptance limits (90 – 110%).
• Sterility: No microbial growth detected in any sample.
• Endotoxins: Below the limit of quantification in all samples.
• pH and appearance: No measurable change. No precipitation, particulate matter, or color shift observed.

Conclusion

Compounded Semaglutide and Tirzepatide vials shipped under GLPFlo's standard cold-chain protocol remain chemically stable, sterile, and clinically viable for at least 7 days following melting of cold packs and exposure to ambient transit temperatures up to 86 °F. A warm vial on arrival is not a quality defect and does not warrant replacement under our refund policy (see Terms of Service §4 and §6).

What you should do on delivery

1. Inspect immediately. Confirm the seal is intact and the solution is clear (no visible particulate, cloudiness, or colour change).
2. Refrigerate at 36 – 46 °F (2 – 8 °C) until first use. If you can't refrigerate within the first few hours, that's fine — your vial is still safe to use.
3. Once opened, the vial may be stored at room temperature (up to 86 °F) or refrigerated for the duration of its beyond-use date (BUD), which is printed on your pharmacy label.
4. Don't freeze the vial. Freezing is the one excursion that can damage peptide medications. If your vial arrives completely frozen solid, contact us — this is one of the red-flag scenarios.
5. Only contact support if you see a red-flag condition. Free replacement when reported within 24 hours of delivery.

Sources & published studies

Independent, third-party evidence backing every claim on this page. All links open in a new tab.

Important: The FDA-approved prescribing information cited above applies to the branded products (Ozempic, Wegovy, Mounjaro, Zepbound). GLPFlo dispenses physician-prescribed compounded preparations of the same active molecule from licensed 503A / 503B compounding pharmacies. Our internal third-party stability assay confirms equivalent thermal behaviour, but the branded labels are cited as the strongest publicly- verifiable evidence that the molecule itself is robust at room temperature.

For the complete report including raw assay data, lab identifiers, and methodology, download the full PDF above. Clinical questions: prescribing@glpflo.org. Quality / shipping concerns: hello@glpflo.org.