Medical cannabis stored incorrectly: what to do in Switzerland

Cannabis medicine left in a hot car, accidentally frozen or affected by a fridge failure? Prepare the details for your pharmacy and clarify use, replacement and treatment.

Your prescribed cannabis medicine was left in a hot car, the fridge failed or a bottle was accidentally frozen. The question goes beyond flavour or how much is left: you need to clarify whether that exact preparation can still be used and how treatment should continue if a replacement is needed. This guide helps you record the incident and prepare the right questions for your pharmacy. It does not remotely certify the quality of an individual pack.

Describe the incident: heat, cold or unknown conditions

Record where the pack was kept, for how long and when you last know it was stored under the intended conditions. Separate measured temperatures from estimates. A warm room, direct sunlight and a closed car are not equivalent descriptions. If a fridge failed, include when you discovered it, any available readings and whether freezing may also have occurred.

An unknown temperature should stay recorded as unknown. Outdoor weather cannot reliably reconstruct the exact temperature of the medicine. Keep the packaging and label, tell anyone helping with your treatment about the incident and store the pack securely according to the available instructions while awaiting advice. Improvised heating, dilution or transfer to another container will not help assess its quality.

Find the instructions for your exact preparation

Use the current label and patient information and, for a pharmacy-compounded preparation, the specific instructions of the pharmacy making or dispensing it. Check the full name, strength with units, formulation and batch. Two oils with a similar THC percentage can have different ingredients, containers and storage requirements. General advice for cannabis flower therefore cannot be applied to every prescribed cannabis medicine.

Distinguish the printed expiry date from any shorter period after opening. Record the opening date if known and check whether instructions differ for sealed and opened packs. An analysis report or an expiry date still in the future does not, by itself, settle a storage incident. Ask the pharmacy to clarify missing information or conflicting instructions rather than selecting whichever is easiest to follow.

Understand storage instructions, batch details and dates

Fridges, freezing and cooling the pack again

Refrigeration is not a universal precaution for all medicines. What matters is whether your preparation requires it and under which conditions. The position inside a fridge may also matter. Do not put the pack in the freezer or directly against a frozen cooling block just to be cautious. Ask about a transport bag and cooling arrangements appropriate for the specific medicine.

If the medicine froze or may have become too warm, returning it to the intended temperature does not demonstrate that its original quality has been restored. Equally, not every deviation automatically means the pack must be discarded. The pharmacy can assess the circumstances using available product data and seek further information where necessary. This article deliberately sets no universal number of hours or temperature allowance for using a potentially affected pack.

What the pharmacy needs to know

Prepare a brief description and, where useful, photographs of the label and packaging. Include the name, strength, batch, expiry, opening date and known conditions of the incident. Say whether the container was open, damaged or leaking and whether anything looks different. Do not alter the medicine to take a clearer photograph or open the container unnecessarily. Keep facts and uncertainties distinct throughout the account.

Unusual colour, particles or damaged packaging should be reported; what they mean depends on the preparation. The absence of a visible change does not prove adequate quality either. Ask for clear advice on whether that pack can be used, what information is still needed and how to store it until you receive an answer. Record the instructions. Share private health information through the direct channel agreed with your pharmacy.

Checklist before contacting the pharmacy

• Full name, strength, formulation and batch.
• Expiry date and known opening date.
• Location, duration and measured temperatures, separated from estimates.
• Packaging damage and visible changes.
• Next planned dose and appropriate stock available.
• Questions about use, temporary storage and possible replacement.

A message you can adapt for your pharmacy

I use [medicine, strength, formulation], batch [detail], opened on [date or unknown]. The pack was [location and conditions] from [time/date] to [time/date]. Measured information: [value or unknown]; estimates: [detail]. Changes or damage: [description]. My next dose is due [time]. Please clarify whether the pack can be used, how to store it while awaiting advice and whether replacement is needed.

Contact the pharmacy dispensing your cannabis medicine

When a dose is due or replacement may be needed

Tell the pharmacy when the next prescribed dose is due and whether you have another correctly stored pack of the same prescribed medicine. State which doses are confirmed. An unresolved quality question is not a reason to increase the dose, independently catch up a missed amount or switch to another cannabis product. Arrange the treatment decision promptly rather than relying on a general rule found online.

If replacement seems necessary, availability, prescription requirements and costs need separate clarification. A storage incident does not automatically entitle you to a free replacement or insurance reimbursement. If you suspect transport damage, document receipt and contact the dispensing pharmacy without prematurely assigning a cause or liability. If the usual practice is closed, use the agreed cover or medical out-of-hours service; call 144 for acute severe symptoms.

If a replacement medicine is not immediately available

If a dose is missed while the question is being clarified

Arrange return and prevent another incident

Do not discard the pack before checking whether it is needed for assessment or return. If the medicine should no longer be used, ask where to take it and how to transport it securely. Do not pour it into a toilet or sink or give it to someone else. Until handover, keep it out of reach of children and protected against unauthorised access.

For future use, keep the original packaging, record the opening date and choose a storage place that follows the product instructions. Before travel, a long drive or transport by a relative, clarify the conditions that need to be maintained. If others help you, agree who checks storage and instructions. Ask what to do if another incident occurs: club membership or a general cannabis guide cannot replace that product-specific plan.

Clarify return and disposal of cannabis medicines

Reviewed: 1 November 2026. General information for Switzerland, not a stability assessment, permission to use a pack or an individual treatment instruction. The exact product information and professional assessment are decisive.