How long skincare lasts after opening (the PAO symbol)
Short answer: look for a small open-jar icon with a number and "M" on the package, such as 6M or 12M. That is the period after opening (PAO): use the product within that many months of the day you first open it.
How to read the label
There are two different dates. The printed expiry date applies to an unopened product. The PAO starts the day you open it, because air, light and fingers change the product from then on.
Typical periods
- Vitamin C serum: often 3–6 months; it can darken as it oxidizes.
- Sunscreen: often 6–12 months; old sunscreen may protect less.
- Moisturizer and cleanser: often 12 months.
- Retinol: often 6–12 months; keep the cap closed and away from light.
Always follow the number on your own product; these are only common ranges.
Why it is easy to forget
Nobody remembers the day they opened a sunscreen in spring. Write the date on the bottle, or keep a list that counts down for you.
How Dewday handles it
Dewday's shelf lets you add each product with the day you opened it and its PAO. It shows a D-day countdown, highlights products within 30 and 7 days, and sends a heads-up 7 days, 1 day and on the day a product reaches its use-by date. Link a product to a routine step and you will see the countdown right on your checklist.
FAQ
What does 12M on my moisturizer mean?
It is the period after opening: use it within 12 months of the day you first open it.
Does the countdown start when I buy it?
No. It starts when you open it. An unopened product follows the printed expiry date instead.
What are signs a product has gone off?
A changed smell, color or texture, or separation. When in doubt, replace it.