Beauty basics · 2 minute read

What the little open-jar symbol is telling you.

By the Viral Beauty editors · October 3, 2026

Reading the period-after-opening mark on your products.

Find the symbol

Many beauty products show a small open-jar icon with a number and the letter M, such as 6M or 12M. It is the manufacturer’s suggested number of months to use the product after opening.

Date it when you open it

Write the opening month on the bottom of the product or on a small label. It takes seconds and removes the guesswork later.

Follow the brand and your own judgment

If a product changes in smell, texture, or color, stop using it and check the brand’s guidance. When in doubt about anything affecting your skin or eyes, ask a pharmacist or dermatologist.