Why expiry dates matter more in cosmetics than you think

There are two dates on most cosmetic packaging, and they mean different things.

The expiry date

This is the shelf life of the sealed product. Past it, preservatives may no longer hold, and active ingredients may have degraded into something less effective — or, in the case of some sunscreen filters, less protective.

The PAO symbol

The small open-jar icon with "12M" or "6M" is the Period After Opening. It starts the day you break the seal, and it overrides the expiry date. A sunscreen with an 18-month expiry and a 12M PAO, opened today, is finished in twelve months regardless of what the box says.

Which products matter most

Sunscreen — degraded filters mean less protection than the label claims, and you will not be able to tell.

Mascara and liquid eyeliner — the highest infection risk of anything in a makeup bag. Three to six months, then replace, regardless of how much is left.

Vitamin C serums — oxidise visibly. If it has gone deep orange or brown, the ascorbic acid has converted and it is no longer doing what you bought it for.

Anything in a jar you dip fingers into — introduces bacteria on every use. Pumps and tubes last better.

How we handle this

B12 allocates stock by expiry date, oldest first, and will not sell a batch expiring within 30 days. That is a rule enforced by the system at checkout, not a target someone in the warehouse is asked to hit.

You can see the batch and expiry information for the stock being offered on each product page.