1. From the appearance: if the lipstick is beaded, or it feels sticky when applied to your hands, and the color is not particularly bright, then the lipstick has expired.

2. Judging from the smell: if the lipstick is placed in a high temperature environment, if it becomes soft or the smell is pungent, it means it has expired.

3. Frequently used places are easy to wear: if lipstick is used too much, or the lid is not tightened, problems such as water loss and bacterial growth are prone to occur, which will also lead to wear and discoloration of lipstick packaging.

Please note that lipstick, like other cosmetics, has a shelf life of about 2-3 years, but this shelf life is not calculated from the time of purchase, but from the date of production. Therefore, it is recommended not to use lipstick for too long, so as not to affect health.