Period after opening
Also called: PAO, Open jar symbol, 12M symbol
Period after opening, or PAO, is the label time a cosmetic product is considered safe to use after you open it, commonly shown with an open jar symbol and a time such as 6M or 12M.
At a glance
- PAO is about the time after first opening, not how long the unopened product has sat in a drawer.
- In EU cosmetic labeling, products with minimum durability over 30 months generally use PAO instead of a best-before date, unless the concept is not relevant.
- The open jar symbol plus 12M means the product should be used within 12 months after opening.
- PAO assumes normal storage and use. Dirty fingers, heat, sunlight, and water getting into the product can shorten real-world comfort.
On this page
The short answer
Period after opening - usually shortened to PAO - tells you how long a cosmetic product should be used after you open it.
You normally see it as a small open jar symbol with a number such as 6M, 12M, or 24M. The M stands for months.
So 12M means: after first opening, use the product within 12 months.
What PAO means on a label
EU cosmetic law says that when a cosmetic product has a minimum durability of more than 30 months, the label generally needs the period after opening instead of a best-before date, unless durability after opening is not relevant[1].
The GOV.UK guidance explains the same practical idea: PAO is the time after opening for which the product is safe and can be used without harm to the consumer, and it is shown with the open cream jar symbol plus months or years[2].
In normal skincare life, PAO is the label's polite way of saying:
"Please do not use this cream forever because you found it behind your hair dryer."
PAO is not the same as purchase date
The clock starts when you open the product for the first time.
That matters because a sealed product stored well is not the same as a half-used moisturiser that has spent a summer in a warm bathroom, met wet fingers, and been opened twice a day.
PAO assumes ordinary use:
- clean hands
- cap closed properly
- no water added to the jar
- product stored away from heat and direct sun
- no obvious smell, colour, or texture changes
If those assumptions are not true, your skin does not owe the product the full 12 months.
Why PAO matters for sensitive or acne-prone skin
Old skincare is not automatically dangerous. But products can change over time, especially after opening.
For sensitive skin, a formula that has changed can feel stingier than it used to. For acne-prone skin, an old, separated, or contaminated product can make the routine harder to read. You end up asking whether the ingredient broke you out, when the real issue may be that the product is simply past its useful life.
This is also why patch testing is still sensible when you reopen an old product and your skin is already reactive.
Mads's practical read
Write the opening month on products you use slowly. A small sticker or marker dot is enough. We do not need a spreadsheet unless you enjoy turning moisturiser into accounting.
Keep products closed, cool, and clean. If a product smells strange, separates, changes colour, or suddenly stings, let it go.
The calm rule: PAO is a helpful label, not a dare. Your routine should make your skin easier to understand, not turn old bottles into mystery guests.
Keep reading
Dictionary
Patch test
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Skin protectant
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Water resistant
Ingredient
Phenoxyethanol
Ingredient
Potassium Sorbate
Ingredient
Benzoic Acid
Ingredient
Dehydroacetic Acid
Condition
Sensitive skin
Condition
Acne and blemishes
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Common questions
What does 12M mean on skincare?
12M usually means the product's period after opening is 12 months. Start counting from the first time you open the product, not the purchase date.
Is PAO the same as an expiry date?
No. PAO is the time after opening. An expiry or best-before date refers to minimum durability before opening under the right storage conditions.
Should I throw skincare away after the PAO date?
If a product is past PAO, smells different, separates, changes colour, stings unexpectedly, or has been stored badly, replace it. Your face does not need a science experiment from the back of the cabinet.