Why storage is part of your treatment

It is easy to think of a tube of steroid cream or a tub of emollient as something that simply sits in the cupboard until you need it. But how you store a topical medicine has a direct effect on how well it works and how safe it is to use. Heat, light, moisture and contamination can all break down the active ingredient, cause the base to separate, or encourage bacteria and mould to grow. A cream that has deteriorated may not control your eczema or psoriasis properly, and in the worst case it can irritate already inflamed skin or introduce an infection. Getting storage right takes a few minutes and it protects your skin, your treatment and your wallet.

Where to keep your creams and ointments

Most topical medicines are happiest in a cool, dry place away from direct sunlight, ideally below 25°C. Check the label or the patient information leaflet, because a small number of products need to be kept in the fridge between 2°C and 8°C, and some need to be kept away from the freezer.

• The bathroom cabinet is usually the worst place. Steam and temperature swings from showers can make creams separate and let microbes multiply.
• Choose a bedroom drawer or a cupboard away from radiators, windows and the cooker. Consistent, moderate conditions are what you want.
• Keep products in their original box or tube. The packaging carries the name, strength, batch number and expiry date, and it shields the contents from light.
• Store out of reach of children and pets. Creams can look like food to a curious dog or toddler.
• Never leave tubes in a hot car or on a sunny windowsill. A glovebox on a summer day can exceed 50°C, which is enough to ruin many formulations.

Expiry dates and the "once opened" rule

The date printed on the box or crimp of the tube applies to an unopened product that has been stored correctly. Once you break the seal, that clock changes. Air, fingers, and repeated opening introduce bacteria, and preservatives in the cream gradually stop holding them back.

As a general guide, most creams and ointments are best used within three to six months of opening, and many pharmacists suggest three months for anything you apply to broken or inflamed skin. Emollients that are preservative-free, especially those in large tubs, often need to be used within a shorter period stated on the label, and they should be decanted with a clean spoon or pump rather than scooped with fingers. If your leaflet or pharmacist gives a specific period, follow that instead.

A simple habit: when you first open a new tube or tub, write the date on the box or label with a marker pen. That way you are not guessing months later.

When to throw a topical medicine away

Expiry dates are a guide, not a guarantee, so use your eyes and nose as well. Discard the product if you notice any of the following:

• A change in colour, or the cream turning grey, yellow or patchy.
• A new or unpleasant smell, or a sour, rancid odour.
• Separation, with a watery liquid leaking from the tube or pooling on the surface.
• A gritty, lumpy or unusually runny texture.
• Visible mould, specks, or a furry appearance.
• The cream has dried out, cracked, or the container is cracked or damaged.
• The label is illegible, so you cannot confirm what it is or when it expires.

If in doubt, throw it out. A replacement prescription costs far less than a flare-up or a skin infection, and never use a topical steroid on broken, weeping or infected skin without medical advice. It is also worth knowing that potency can drop over time, so an old tube may not deliver the dose your skin needs.

Hygiene, sharing and travel

Keep your medicines to yourself. Sharing a cream, even with a family member who has a similar rash, risks spreading infection and gives you no control over how the product has been stored or contaminated. Never decant creams into unlabelled pots, and always wash your hands before and after applying, unless the product is designed to be applied by hand to the affected area as directed.

When travelling, keep topical medicines in your hand luggage so they stay with you and remain at a reasonable temperature. Use a small clear bag, keep them in their boxes, and avoid leaving them in a parked car or a hot hotel room. If you are flying, remember that liquids, creams and ointments are subject to airport security limits, so check current rules before you pack.

A simple routine that protects your skin

• Check expiry dates each time you start a new tube, and again every few months for products in use.
• Write the opening date on the packaging.
• Store in a cool, dry cupboard, not the bathroom.
• Review your supply every three to six months and dispose of anything past its date or looking changed.
• Return unwanted or expired medicines to a pharmacy for safe disposal. Do not flush them down the toilet or pour them down the sink.
• Order replacements before you run out, so you are never tempted to stretch an old tube.

Good storage is a small, steady habit that keeps your treatment reliable. If you are unsure whether a cream is still fit to use, ask your pharmacist, they would much rather answer that question than help you manage a flare caused by an out-of-date product.