What is a scalp scrub?
The main function of a scalp scrub is exfoliation, which Dr. Jack says helps to "reduce the level of dead skin cells and debris around the hair follicles as well as excess sebum, which can be a cause of dandruff and irritation."
Majority of scalp scrubs do this via mechanical exfoliation (using granules), but also chemical exfoliation, with the inclusion of actives and acids.
What are the benefits of using a scalp scrub?
The benefits of scalp exfoliation are similar to that of skin exfoliation; first and foremost removing dead cells for a clearer, smoother texture, and to allow following products to penetrate better.
"And secondly, there are the benefits of the ingredients themselves, such alpha hydroxy acids, which have antioxidant and oil-controlling effects on the scalp," Dr. Jack tells Marie Claire.
Who should be using scalp scrubs and how often?
Scalp scrubs are particularly great for "people who use dry shampoos, hair oils and masks, or who perhaps don’t wash their hair every day," says Dr. Jack.
"Scrubs nowadays can also contain ingredients targeted towards different scalp issues; with products available for dry scalps, oily scalps, dandruff-prone, coloured hair, fine hair, etc."
As for how often you should scrub, Dr. Jack says, "This really depends on the condition of the scalp and if the scalp is tending more towards dryness or oiliness."
"For oily scalps, a once-weekly scrub can sometimes help significantly, but for dryer scalps it may be better to scrub less frequently, ie. once every two to three weeks."
Are there any downsides to using a scalp scrub?
Like all exfoliating products, if you're prone to sensitivity, it's best to do a patch test or seek the advice of a dermatologist before proceeding with a scrub.
"If you have a sensitive scalp be cautious about using drying products or products with high levels of active ingredients, particularly BHAs or AHAs," advises Dr. Jack.
Likewise, if you have a diagnosed skin condition like eczema or psoriasis, you should consult your GP.