It's unlikely that anyone would think of sharing their toothbrush. But with regard to other items, we are less categorical than we should be.
Let's list three cases in which a request to borrow this or that thing should be followed by a strict "no."
Mascara
If you neglect this rule regarding mascara, you risk getting conjunctivitis.
The thing is that bacteria can use the mucous membrane of the eye as an invitation to get into your body. Unlike the skin, it cannot boast a powerful protective function.
Face Brushes
Brushes with soft bristles are usually used in front of the mirror in the bathroom, which is a room with high humidity. Accordingly, the most favorable conditions for the reproduction of microbes are created here.
If you don't want to get warts and pimples, maybe it's better to do without powder? It's much more pleasant than having to treat skin problems at a dermatologist later.
Lipstick or lip gloss
If you don't want to get a cold sore, don't rush to share your lip product with someone else.
The skin of the lips is extremely thin and has no sweat glands. For these reasons, the lips are prone to cracking and peeling, which means they are vulnerable to infections.