MHRA Issues Summer Medication Storage Warning
As summer travel peaks and seasonal temperatures climb, health and social care professionals are being urged to remind patients about the dangers of improper medicine storage.
On July 17th, 2026, the UK’s medicine regulator launched an urgent reminder as part of its “Summer-proof your health” campaign. The warning highlights a hidden summer risk: leaving everyday medications in hot cars, packed luggage, or on sunny windowsills can significantly break down their active ingredients, leaving them less effective or completely unusable.
Who is the MHRA?
The Medicines and Healthcare products Regulatory Agency (MHRA) is the executive agency of the Department of Health and Social Care in the UK. Functioning as the UK’s independent regulator, the MHRA is responsible for ensuring that all medicines, medical devices, and blood components used in healthcare meet strict standards of safety, quality, and efficacy. When emerging risks—like seasonal weather spikes—threaten patient safety, the MHRA steps in to issue national clinical guidance.
The Hidden Risk of Hot Weather
Many common medications are chemically formulated to be stored at room temperature, strictly below 25°C.
During hot weather or travel periods, spaces like parked vehicles, caravans, tightly packed suitcases, and sunlit rooms rapidly surpass this safety threshold. When subjected to excessive heat:
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Chemical Degradation: The active ingredients can break down prematurely, rendering the dose weaker or completely ineffective.
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Altered Absorption: Heat exposure can change how the human body processes the medication, meaning a patient could inadvertently receive a dose that acts too strongly or too weakly.
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Physical Damage: Devices like pressurized inhalers can physically fail or burst in high temperatures.
Which Medications and Devices are at High Risk?
While all medications should be monitored, the MHRA highlighted several high-risk treatments that are highly sensitive to temperature fluctuations:
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Insulin: Highly temperature-sensitive and requires strict cold-chain or stable room-temperature management to prevent the proteins from breaking down.
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Inhalers: Heat can warp the delivery system or destabilize the aerosolized medicine inside.
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Topical Creams: Medicated skin creams and ointments can separate or liquefy under high heat, changing the concentration of the active formula.
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Hormonal Contraceptives: Extreme heat can reduce the efficacy of oral contraceptives or emergency hormonal treatments.
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Emergency Devices: Adrenaline auto-injectors (such as EpiPens) can degrade quickly if exposed to direct sunlight or car glove boxes.
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Diagnostic Tools: Blood glucose monitors and continuous glucose monitoring (CGM) test strips can deliver inaccurate readings if stored in humid or hot environments.
The July 17th MHRA Guidance: Key Advice for Patients and Carers
To safely manage medications through the remaining summer weeks, the MHRA has outlined four clear steps:
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Check the Packaging Immediately: Patients should look at the outer packaging or the digital Patient Information Leaflet (PIL) to verify specific storage requirements, particularly regarding refrigeration or light protection.
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Rethink Summer Travel Storage: Never leave medicines in parked cars or inside luggage exposed to the sun. When out all day or traveling, consider using an insulated cool bag to protect sensitive treatments.
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Optimize Home Storage: Keep medications out of naturally humid or warm household spaces like bathrooms or sunny windowsills. Find a cool, dry, shadowed shelf instead.
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Inspect Before Injecting or Ingesting: If a medication has visibly changed color, developed an unusual odor, or changed in consistency, it could be a sign of heat damage.
Important Safety Note: If a patient or carer notices a change in how a medication looks, or if the user feels their symptoms are returning despite taking their normal dose, they should consult a pharmacist right away.
For comprehensive information on keeping healthcare products safe this summer, or to access specific patient leaflets, visit the official MHRA website.