Start with the PAO symbol
The PAO symbol is the open-jar icon that usually says 6M, 12M, or 24M. It tells you how long the formula is expected to remain stable after first opening under normal use.
If a product has no printed PAO, use the category as your guide. Eye-area products, sunscreens, and unstable actives should be judged more strictly than dry powders or sealed backup items.
- 6M means about six months after opening.
- 12M is common for many creams, serums, and foundations.
- When in doubt, choose the stricter replacement window.
Which opened products should be replaced earlier
Products used around the eyes or in wet conditions usually deserve shorter use windows. Mascara dries out, liquid liner tips get contaminated, and pump-free jars are exposed every time you dip into them.
By contrast, pressed powders and pencils often age more slowly if they are kept dry, closed tightly, and used with clean tools.
- Replace mascara and liquid liners early.
- Be strict with jar creams touched by fingers.
- Powders last longer when kept clean and dry.
Red flags that matter more than the date
Stop using a product if it smells off, looks darker than usual, separates in a way it did not before, or feels unusually gritty, sticky, or watery. Those changes often matter more than a theoretical month count.
If you are unsure, compare the current product against a newer bottle from the same line, or test the texture on the back of the hand before using it on the face.
- Trust obvious smell and texture changes.
- Do not try to finish products that irritate or sting unexpectedly.
- Write the month opened on slow-use products.
