How often should we wash our hair?

How many times a week should you wash your hair?

Finding the right frequency for washing your hair is not always straightforward. Washing too often is frequently blamed for making hair brittle and dry. Conversely, if it is not washed often enough, it becomes greasy and dull. How can you find the right balance? Here are our recommendations for keeping your hair clean and in good health.

Published on August 2, 2023, updated on April 1, 2026, by Manon, Scientific Editor — 5 min of reading

A hair-washing frequency to adhere to?

As a general rule, washing the hair every day is often discouraged, but this recommendation is partly based on a misconception. In fact, our hair produces a lipid fluid called sebum, which protects the scalp and hair from external aggressions. Shampoo is an emulsifying product that captures and removes excess oil, dirt and residues of hair products. If it is well formulated, it should neither dry out the scalp nor weaken it.

Moreover, contrary to what is often claimed, frequent washing does not lead to an overproduction of sebum. This effect is mainly observed when overly harsh shampoos disrupt the scalp, causing reactive hyperseborrhoea. Conversely, with gentle, suitable formulations, and by using a conditioner to protect the hair fibre, frequent washing does not weaken the hair.

The frequency of hair washing is therefore not subject to strict rules.

It is more closely linked to factors such as your hair type, its texture, your lifestyle and even your environment. Thus, how often you wash your hair is above all a personal decision, based on your own comfort, perception and sense of well-being. For example, some people with coily, dry or very curly hair wash it once a week without this causing any particular problem. This frequency is explained both by the naturally drier nature of this hair type and by practical constraints, as caring for it takes longer and often requires restyling after washing. Conversely, people with straight hair often prefer to wash it more frequently, to avoid a flat appearance and visible greasiness.

That said, if you do not wash your hair often enough, excess sebum, dirt, pollution particles, dust and dead skin cells can build up, just as they do on the skin of the face. This can cause itching, irritation and visible flaking. A study has in fact examined the effects of infrequent washing on the scalp. The researchers observed that the quantity of yeasts of the genus Malassezia increased over time after the last shampoo. This micro-organism feeds on sebum, which it converts into fatty acids that can trigger an inflammatory response, leading to itching and redness. It is also involved in the development of dandruff and seborrhoeic dermatitis.

It was also observed that the severity of itching increased significantly within 72 hours after shampooing, coinciding with a progressive build-up of sebum and promoting the proliferation of Malassezia. Conversely, increasing the frequency of hair washing helped to reduce flaking, redness and itching, as well as the quantity of Malassezia and the level of pro-inflammatory cytokines. The same study showed that daily hair washing did not damage the hair fibre and contributed to improving scalp comfort.

Ultimately, there is no universal washing frequency. If your hair is visibly oily, if your scalp feels itchy or shows flaking, these are signs that it is time to wash it. Conversely, if your scalp feels comfortable, with no sensation of excess oil or discomfort, there is no need to increase the frequency. The key factor remains choosing products suited to your scalp, in order to cleanse it effectively without disrupting its balance.