EU vs US peptide storage labels
A semaglutide pen sold in Europe says "room temperature 22–25 °C." The same drug sold in the U.S. says "room temperature 59–86 °F." The numbers are different on purpose — different regulatory conventions, different climate assumptions — but the underlying chemistry is identical. The practical implication is mostly about how to handle travel between regions.
The two label conventions
| Property | EU / EMA convention | US / FDA convention |
|---|---|---|
| Refrigerator | 2–8 °C | 2–8 °C / 36–46 °F |
| "Room temperature" in-use | 22–25 °C (sometimes "below 30 °C") | 59–86 °F (15–30 °C) |
| Maximum permitted | ≤30 °C | ≤30 °C / 86 °F |
| Freeze warning | Do not freeze | Do not freeze |
Why the windows are different
The stability data behind both labels is the same — Novo Nordisk and Eli Lilly file dossiers in both regions covering temperatures from 2 °C to 40 °C. The choice of which range to print on the label is a regulatory and marketing decision:
- EU convention historically labels the optimal storage range (typical European indoor temperature), with a separate "maximum" allowable temperature. Most pharmacists in the EU keep pens at the lower end.
- US convention labels the full allowable range, anticipating broader climate variability across U.S. regions. A patient in Phoenix and a patient in Vermont need the same label.
Practical travel implications
Buying in the US, traveling to Europe
No issue. The labeled US temperature range (15–30 °C) covers normal European indoor temperatures comfortably. The pen is in spec everywhere it would be in spec at home.
Buying in Europe, traveling to the US
The labeled EU range (22–25 °C) is narrower than typical U.S. indoor variation, especially in summer. If you take an EU-labeled pen to a warmer U.S. location, you may be technically out of label for some hours even though the drug is fine. The actual stability data extends to 30 °C; pen integrity isn't affected.
Travel in a warm climate
Cumulative time above 30 °C is the real concern (see peptide degradation above 86 °F). Both EU and US labels agree on the 30 °C upper limit; what differs is how prominently it's called out. An insulated travel case keeps you in spec regardless of which label you have.
What this means for compounded products
Compounded peptides typically inherit the pharmacopoeia of the country where they're compounded:
- US 503A compounded: follows USP guidance and FDA conventions. Expect US-style labels (15–30 °C or 59–86 °F).
- EU compounded: follows European Pharmacopoeia. Expect EU-style labels (typically narrower room-temperature range).
- "Research use only" non-pharmaceutical: no consistent label. Default to the safest range (2–8 °C refrigerated).
Compounded GLP-1 specifically
Compounded semaglutide and tirzepatide vials usually require continuous refrigeration regardless of pharmacopoeia. The compounded form lacks the manufacturer's long-term stability validation at room temperature, so most pharmacies are conservative: "store refrigerated, do not freeze." A 56-day in-use room-temp window like the brand-name pens is rarely a compounded label claim.
Reading any label, in any units
Quick conversions you should know:
| °C | °F |
|---|---|
| 2 °C | 36 °F |
| 8 °C | 46 °F |
| 15 °C | 59 °F |
| 22 °C | 72 °F |
| 25 °C | 77 °F |
| 30 °C | 86 °F |
| 40 °C | 104 °F |
The customs / regulatory angle
Beyond temperature labels, traveling with peptides across borders has separate considerations — customs declarations, prescriptions in the local language, controlled-substance status in some countries. See the country-by-country travel rundown.
FAQ
Is a pen bought in Europe legal to bring into the US?
For personal use, generally yes — FDA allows reasonable personal-use quantities of prescription drugs not approved in the US, subject to certain conditions. Customs may inspect; carry the original packaging and a prescription.
Do the labeled in-use windows differ between EU and US?
For semaglutide and tirzepatide, the after-first-use windows (56 days and 21 days respectively) are the same in both regions. The temperature range during that window is what differs in labeling.
What if I bought a pen in a country with no clear label?
Default to refrigerated storage and 30 °C upper limit. Both are universally safe.
Does shipping internationally count against the labeled limits?
Yes, cumulatively. International couriers typically use cold-chain shipping for pens; ambient transit (24+ hours at room temp) eats into the in-use window. Refrigerate immediately on arrival.
Related reading
Convert labels automatically
Peptide Protocol shows labeled storage windows in whichever units you prefer, regardless of where the pen was sold.
Get the iPhone app →Informational and educational only. Not medical advice. Consult a licensed clinician before starting, changing, or stopping any peptide protocol. Mentions of investigational, compounded, or research-use peptides are for informational purposes; many such substances are not FDA-approved for human use.