Sunscreen
Yes — sunscreen expires. Unopened, it stays effective for about 3 years (the FDA requires this); once opened, use it within about 12 months. After that the UV protection is no longer reliable.
Why sunscreen expires
Sunscreen protects the skin with chemical or mineral UV filters. Those filters are delicate: over time, and with oxygen, heat and light, they break down and lose effectiveness. Expired or overheated sunscreen no longer reliably prevents sunburn — and therefore the biggest risk factor for skin cancer. Unlike many products, this is directly about your health.
Unopened, sunscreen stays stable until its printed date; US regulations require it to remain effective for at least three years, so if there is no date, count three years from purchase. Once opened, the little open-jar symbol with a number applies — "12M" means twelve months. Heat is the biggest enemy: a bottle left in a hot car all summer or in direct sun at the beach can lose its protection even before the date.
Because this is about protection from sunburn, it pays to err on the safe side. Sunscreen is relatively cheap, while a sunburn stresses the skin lastingly and raises the risk of skin cancer. If you are unsure whether last year's opened bottle still protects, replace it with a fresh one — that is the safe choice.
How do I know it needs replacing?
These signs mean it is time to replace the sunscreen:
If the expiry date has passed, or opening was longer ago than the stated months, replace the sunscreen.
If the cream has separated, gone grainy, clumpy or watery, the filters are no longer evenly distributed.
A rancid or sharp smell, or a clear change in colour, shows the product has aged.
Shelf life at a glance
Opened or not, and how it is stored, decides the protection:
| State | Shelf life |
|---|---|
| Unopened, stored cool | about 3 years (or its date) |
| Opened (symbol "12M") | about 12 months |
| Hot car / direct sun | protection may fade sooner |
| Separated, rancid, discoloured | replace |
Store & apply it right
The right handling keeps the protection intact:
Store cool and shaded — do not leave it in a hot car or in direct sun at the beach.
Apply generously — full protection only comes with enough product, about a shot-glass amount for the whole body.
Reapply regularly — after swimming, towelling off and sweating.
Check each season — inspect last year's opened bottles before your trip.
Common myths
Dangerous half-truths surround sunscreen:
Wrong — the UV filters break down. Expired sunscreen no longer reliably prevents sunburn.
It depends — kept cool and within the "12M", yes; after heat in a car, better to replace it.
No — the stated protection only holds with a generous amount. Applied too thin, it drops sharply.
If you apply sunscreen regularly and generously all summer, a bottle is usually used up within one season anyway — so the expiry question rarely comes up. Tip — write the opening date on the bottle with a waterproof pen so you keep track of the "12M".