When does skincare expire? Reading the PAO symbol
There is a jar at the back of the cupboard and you cannot remember whether you opened it last winter or the winter before. There is no obvious expiry date on the base. That is common because most skincare is labelled with a period after opening instead of a calendar date.
The missing fact is not when you bought it. It is when air, fingers, or an applicator first reached the formula and started the labelled open period.
When does skincare expire?
Most skincare follows the period after opening printed on its packaging, so the clock starts when you first open it, not when you buy it. Look for an open-jar symbol marked with months, such as 6M or 12M. Products with shorter unopened durability may carry a calendar date instead.
The label is the starting point because formula, packaging, and testing differ. A date or PAO period is not extended by how full the container looks. Storage instructions matter too: heat, direct sun, water, and repeated contact can change what happens before the labelled period ends.
What is the PAO symbol?
The PAO symbol is a small open jar followed by a number and M, meaning the number of months the product is intended to remain usable after opening under its labelled conditions. Under EU cosmetics regulation, products with minimum durability over 30 months generally use PAO; those at 30 months or less carry a real date.
EU Cosmetics Regulation 1223/2009, Article 19 requires the date of minimum durability or, for products lasting more than 30 months unopened, the period after opening where that concept is relevant. Annex VII shows the open-jar symbol. The M means months, not a manufacturing date.
| PAO period | What it means | Categories that may carry it |
|---|---|---|
| 6M | Use within six months of opening | Eye-area treatments, some water-based treatments, and shorter-life formulas |
| 12M | Use within twelve months of opening | Cleansers, moisturisers, serums, and sunscreens |
| 24M | Use within twenty-four months of opening | Some balms, oils, powders, and longer-life formulas |
These categories are examples, not a way to guess a missing label. Two serums can have different PAO periods because their formula, packaging, and stability testing differ. Read the symbol on the exact container and keep the outer packaging until you have transferred any important date or instruction.
Does an unopened product expire?
Yes, unopened skincare has a finite period of minimum durability, but it is measured differently from PAO. If that period is more than 30 months under EU rules, a calendar date may not appear and the PAO starts only after opening. If it is 30 months or less, the label carries a date.
Unopened does not mean unaffected by storage. A sealed container kept in heat or direct sun has not started its PAO clock, but it may not have been stored under the conditions used to establish durability. Follow any storage wording and do not use the purchase date as a substitute for a printed minimum-durability date.
How do you know when you opened it?
Record the opening month once, at the moment the product joins your active shelf. You can write it on the container or save the opening date in your log. That one fact answers the question later without asking memory to separate one winter, sale, or half-used bottle from another.
Find the PAO or date first
Check the container and outer packaging before discarding anything. Record the exact period, such as 12M, rather than assuming one year from the category.
Mark the first opening
Write the month and year on the bottle, or add the opening date once in your shelf record. Use the date you first opened it, not the purchase date.
Keep the stop reason
When it leaves your shelf, note whether you finished it, reached the labelled period, or stopped for another reason. That keeps expiry and performance from becoming the same conclusion.
An opening date also improves cost records because it shows how long the container was active. Pair it with the cost-per-use calculation if you want to distinguish something you finished from something that expired half full.
What actually changes in an old product?
You may notice a change in smell, colour, texture, or separation as a product ages. A pump may dispense differently, a cream may split, or a familiar scent may become unusual. These observations cannot tell you the cause or guarantee safety, but they are reasons to stop using that container.
Do not stir, shake, or add water simply to hide an unexpected change unless the label specifically says the formula should be mixed. If the appearance or smell has changed, the packaging is damaged, the contents are contaminated, or you cannot identify how long it has been open, stopping is simpler than trying to prove it is fine.
Reaching the PAO does not tell you whether the product worked, and stopping early does not tell you it failed. Keep the reason in the record. The guide to when to stop using a skincare product separates visible results, comfort, routine fit, and the practical end of a container.
FAQ
What does 12M mean on skincare?
The open-jar symbol marked 12M means a period after opening of twelve months. Count from the first time you opened the product, not from the purchase date.
Why does my skincare have no expiry date?
Under EU rules, a cosmetic with minimum durability over 30 months does not need a calendar date and generally shows a period-after-opening symbol instead, where opening affects durability.
Can I use skincare after the PAO period?
The PAO is the labelled period for use after opening under the stated conditions. Once it has passed, or if smell, colour, texture, separation, or packaging changes unexpectedly, stop using that container rather than guessing.
Does the PAO clock start when I buy skincare?
No. PAO starts when you first open the product. A separate date of minimum durability, if present, applies to the unopened product under the labelled storage conditions.
Glaze records the opening and stop dates on your shelf, so a tiny jar symbol does not have to rely on memory.