A new revelation indicating the presence of cancer-causing ingredients in some dry shampoos may have you reconsidering your hair care regimen.

However, experts say there is no one-size-fits-all answer to how frequently you should wash your hair — or what you can do to keep it looking good on bad days.

Dr. Anthony Rossi, an assistant attending dermatologist at Memorial Sloan Kettering Cancer Center in New York City and a fellow of the American Academy of Dermatology Association, said as quoted by CNN: “Some people just think that they have to wash their hair every day or they’re going to get very greasy hair.”

The frequency with which you should wash your hair is determined by a variety of factors, including hair type and style, how oily your scalp gets, and your level of activity.

Here’s when to wash your hair 

Rossi recommends that his patients wash their hair once or twice a week. However, if you've had chemical treatments that can make your hair dry, such as bleach, perms, or relaxers, you may want to wash it less frequently than once a week to avoid breaking or brittle hair or split ends, he said.

If your scalp is excessively oily, you may need to wash it as frequently as once every day, as per Rossi. Your age can also play a role.

If your hair is curly or oily, it may be more prone to drying out or breaking, as per the association. Washing it too frequently might aggravate this, so thick, curly hair shouldn't be washed daily or even weekly, according to the association.

However, to maintain your scalp and hair clean and healthy, you should wash it at least every two to three weeks.

It is worth noting that hair and scalp care also happens between washes to keep its cleanliness and look — as well as safeguard it from harm.

If you sweat frequently when exercising, you don't need to shampoo your hair every time unless there is an overgrowth of bacteria or your hair or scalp begins to smell, according to Rossi. If you like, you can rinse it with water.

If you find extra oil around your hairline, he suggests wiping it away using cosmetic blotting sheets.

Chlorine can make your hair dry and brittle if you swim in a pool with your hair exposed to the water. 

According to the American Academy of Dermatology Association, protect your hair by soaking and conditioning it beforehand, wearing a fitting swim cap, and replenishing any lost moisture immediately afterward with shampoo and deep conditioner specially made for swimmers.

If you have ongoing problems with your scalp or hair, such as dandruff, hair loss, or brittle hair, Rossi recommends seeing a board-certified dermatologist who specializes in these conditions.