Storage rules for weight-loss pens and tablets depend on the exact product and on whether you have started using the pack. Read the leaflet for your product. If you are unsure whether a pen or tablet was stored correctly, ask the dispensing pharmacist before you use the medicine.
Find the storage leaflet for your exact product
Storage rules come from the leaflet for your exact product. Keep the leaflet from the pack. If you need a new copy, search by the product name and form, such as pen or tablet. A rule for one injection pen does not apply to another pen or to a tablet. Starting a pack can also change how long you may keep the pack.
The Mounjaro KwikPen leaflet and Boots’ Wegovy information are examples of product-specific sources. We have chosen not to merge their storage rules into one general temperature chart.
If you switch pharmacy every month, read the leaflet in each new pack.
Keep a record of in-use dates and packaging
- Note the start date of an in-use period, if the product instructions ask you to.
- Keep the original packaging with its label, where the instructions say so.
- Store the medicine away from children and follow the pack’s handling instructions.
- Ask the pharmacist if your home cannot meet the storage rules.
An expiry date does not override the in-use limit. Check both.
Pen left in a hot car, frozen or delivered late
Your medicine may have been left in a hot car, frozen, arrived late or spent an unknown time outside its storage conditions. Tell the dispensing pharmacy. Give them:
- the product name,
- how long the problem lasted,
- the rough conditions, and
- whether you had started using the medicine.
Putting the medicine back in proper storage does not undo damage. Never test a suspect pen or tablet by taking a dose. The pharmacist can advise based on the product and what happened.
Travelling with weight-loss medicine
Ask the pharmacist how to carry and store your specific medicine. Check airline and destination rules separately. Keep the original dispensing label (the pharmacy sticker on your box) with you. Our travel preparation guide lists questions to ask. Rules for each country still apply.
Frequently asked questions
Do all weight-loss pens have the same storage rules?
No. A storage rule for one weight-loss injection pen does not apply to another pen or to a tablet. Check the leaflet for your exact product. Starting a pen can also change how long you may keep the pen.
What should I do if my weight-loss pen was left in a hot car or froze?
Tell the dispensing pharmacy the product name, how long the pen was exposed, the rough conditions and whether you had started using the pen. Never test the medicine by taking a dose. Putting the pen back in storage does not undo damage.
Can I use an opened weight-loss pen until its expiry date?
Not always. An expiry date does not override the in-use limit for an opened weight-loss pen. Note when the in-use period starts if the product instructions ask you to, and check both dates.
How do I store weight-loss medicine when travelling?
Ask the pharmacist how to carry and store your specific weight-loss medicine, then check airline and destination rules separately. Keep the original dispensing label with you while you travel.
Sources
Links checked on 6 October 2026. Provider prices and policies change, so confirm the details with the provider before you pay. The organisations linked here have not reviewed or endorsed this guide.
- Lilly: Mounjaro KwikPen patient information leaflet, via emc
- Boots Online Doctor: Wegovy treatment information
Pharmacy Hopper does not give medical advice. Read our editorial standards.