How Does Dry Shampoo Work Exactly?
Updated: Apr 7, 2021
There are two types of dry shampoo: alcohol based and starch based. That said, some formulas contain both! Check the ingredients and if an alcohol is higher on the list, the product will work better for volume and mild grease. If a starch is listed higher in the ingredients, the product is designed more to tackle tough grease.
Enjoy this read and, as always, click the numbers in square brackets to check out all the references!
What is Dry Shampoo?
For anyone who hasn't heard of it before dry shampoo is a classic greasy hair quick fix. It's a product you put on oily hair that makes the hair look clean and grease free. There are a few old school homemade dry shampoos like baby powder and cocoa powder but mostly people buy one of two types of dry shampoo.
Alcohol Based Dry Shampoo
These are often the dry shampoos that come in sprayable formulas but alcohol can be added to any type of dry shampoo. The alcohol works by drying the grease in your hair, similar to how acne cleansing wipes sometimes contain alcohol to dry grease from your skin. These formulas generally feel a bit lighter and add some volume to finer hair [i]. If your hair gets greasy fast, but only lightly greasy, this might be a good choice for you.
Listed ingredients that are alcohols [ii]: ethanol, propanol, propyl alcohol, isopropyl alcohol and anything that is paired with the word alcohol like “lauryl-alcohol, cetyl-alcohol, stearyl-alcohol, etc.”
Starch Based Dry Shampoo
These can be powder, spray, foam, or paste formulas. When these are put on the greasy roots of your hair the starch soaks up the grease and then you can brush out the excess product. These formulas are a bit heavier and can leave a white-cast in your hair. They tend to remove oil better than just alcohol but if you use too much you will look like you just took off a powdered wig. If you have super greasy hair this might be your choice.
Listed ingredients that are starches [iii]: cyclodextrin, any compound words that include “starch”
Does dry shampoo clean my hair?
No, the term shampoo is used very liberally here. It just makes your hair look clean but there is no cleansing aspect. They can also be heavily scented to make you feel like your hair is fresh but this can be an irritant to some people. After using it your greasy hair is still greasy hair.
Is using dry shampoo healthy for my hair?
In small amounts used occasionally it is fine to use. It can also help you extend time between washes which can promote healthier hair [iv].
However, remember that you are adding an extra layer of stuff onto your scalp. This can be a problem because if you are also using shampoos that leave residues behind (ex. silicones) you can end up with a thick layer of junk that clogs your hair follicles [v]. This is similar to clogged pores and can cause scalp buildup which if left for too long can cause hair loss [vi]. So keep in mind that when you use dry shampoo use a good hair cleanser the next time you’re in the shower.
If you want some more tips about hair cleansers, click here to read about 3 ingredients to avoid in your shampoo.
Another issue is if you are using an alcohol based formula too often you can severely dry out your scalp. This can cause the follicles in your hair to create even more sebum so you end up with even greasier hair [vii].
How to use dry shampoo
Spray
Shake your can and then hold it about 15cm (6”) away from your scalp.
Spray small amounts at a time where your roots look greasy.
Massage the product into your roots.
Brush out any excess.
Style as desired.
Powder
Shake your container.
Squeeze out small amounts of powder onto the greasy areas of your scalp.
Leave the powder in to soak up the grease for a few minutes.
Brush out the excess.
Have a patch that’s still white after brushing? Just wet the tips of your fingers and rub that part of your scalp until the white disappears.
Style as desired.
Paste or Foam
Take a small amount of product onto your fingertips.
Rub the product into the greasy parts of your hair.
Brush out any excess.
Style as desired.
Remember, follow the instructions on the label of your product of choice!
My Thoughts
I am an occasional user of dry shampoo but I generally only use it to push my hair one more day without washing and after applying it I will style my hair in a bun or pony tail. This product is best used with a “less is more” approach and I think it’s important to say that it isn’t a miracle cure.
If your hair is really greasy, just wash it.