Beauty Product Checker
The little open-jar symbol on your packaging is a Period After Opening figure. Here is how to read it, what it covers, and where it stops being useful.
An open cosmetic jar with a number and the letter M inside. 12M means twelve months of expected stability from the day you first open it.
Starts at first opening, not at manufacture and not at purchase. Write the opening month on the base with a marker — it is the simplest habit in beauty.
PAO assumes sensible storage: room temperature, out of direct sun, cap closed, clean applicators. Poor storage shortens it considerably.
A practical reference for auditing your collection.
| PAO | Typical products | What to watch |
|---|---|---|
| 3M | Mascara, liquid eyeliner | Highest infection risk — replace on time. |
| 6M | Liquid foundation, water-based serums, cream eyeliner | Watch for separation and smell changes. |
| 12M | Cream blush, gloss, moisturiser, most skincare | Airless pumps last longer than open jars. |
| 18M | Pressed powders, some balms | Keep sponges and brushes clean. |
| 24M | Eyeshadow palettes, lipstick, loose powder | Anhydrous formulas are the most stable. |
| 36M | Highly stable anhydrous products | Rare, but seen on oil-only formulas. |
Eye products deserve stricter rules
Sunscreen is different
Keep going
PAO tells you how long a product lasts after opening. The batch code printed on the packaging hints at how old the unit already is. Together they give a realistic picture of freshness.
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