Your Makeup Has an Expiration Date. Here's What That Actually Means.

Most people know makeup expires. What most people do not know is what that actually means for their skin.

Expiration is not about tidiness. Every cosmetic formula contains a preservative system designed to keep it stable and safe for a specific window of time. Once that window closes, the product becomes vulnerable to bacterial growth and ingredient breakdown. It can look and smell completely normal and still be past the point where its chemistry is protecting you.

For rosacea-prone or reactive skin, this is where it gets personal. I have had clients come in convinced their skin was getting worse, cycling through new products, eliminating things from their routine, and the problem was a foundation they had been using for two years. Irritation that feels random is often traceable to something that has simply been open too long.

What the symbol on your packaging actually means

Most cosmetics include a Period After Opening symbol, a small open jar with a number and the letter M printed on it. That number is how many months the product is considered stable after you first open it. A 12M means 12 months from opening, not 12 months from purchase. The PAO clock starts the day you break the seal.

Some products also carry a printed expiration date, which refers to the product unopened. SPF products always have one, and it is not optional. The FDA regulates sunscreen actives, and protection degrades meaningfully past that date. An expired SPF product is not giving you reliable coverage.

How long things actually last

These are general industry standards. Storage conditions matter. Heat, humidity, and direct sunlight all accelerate degradation, so a product kept in a hot environment will not last as long as the PAO suggests.

Mascara and liquid eyeliner: 3 months. These are used near the eye and reintroduced to a moist environment with every application. They accumulate bacteria faster than anything else in a makeup bag. This one is non-negotiable.

Liquid and cream foundation: 6 to 12 months. Water-based formulas are more vulnerable to microbial growth. Pump packaging helps by limiting air exposure.

Concealer: 6 to 12 months for liquid formulas. Stick concealers can last up to 18 months if stored properly.

Powder products: Up to 2 years. Very little water content makes them significantly more resistant to contamination. The main issue over time is oil buildup, which affects texture.

Lip products: Gloss and liquid lipstick, 6 to 12 months. Bullet lipstick(traditional), 1 to 2 years. Lip liner, up to 2 years if regularly sharpened. 

When to discard before the date

PAO dates are estimates based on controlled storage conditions. Your bathroom is not a controlled environment. Use your senses as a backup check.

Separation in a liquid that does not reincorporate when shaken means the emulsion has broken. A smell that is sour, rancid, or just off means bacterial activity or ingredient breakdown. Graininess in a previously smooth formula, or a thick tacky mascara, are both signs of degradation. Visible color shifts mean oxidation.

If any of these are present, the date on the packaging is no longer relevant. Discard it.

A system that takes five seconds

Write the date you opened a product on the bottom of the packaging with a fine-tip marker. That is it. Do a ten-minute audit twice a year. Finish one product before opening the next in the same category.

What you put on your skin should be working in your favor. Expired makeup is not.