Your scalp can’t quite decide what it is. It falls into both the “skin” and “hair” categories, and requires special treatment on both fronts to ensure that it’s being cared for the right way. And it all starts with the way we shampoo.

“Proper scalp care is often overlooked by many people since the focus is mainly on the aesthetic of hair itself,” says Shab Reslan, a trichologist and hair health expert at HairClub.  “Much like the importance of quality soil in order for a plant or flower to grow from, the scalp requires a balanced and healthy environment in order to grow its best hair.” The best way to do that? By using the right products and applying (and removing!) them properly.

“The biggest mistake people make when washing hair is not washing sufficiently and leaving product or sebum residue,” says Reslan. To properly dislodge product, oil, and any other sort of build-up from your scalp, she recommends doing a double shampoo whenever you wash (ideally every other day), and sticking with gentle formulas instead of anything with harsh surfactants like sodium lauryl sulfate or sodium laureth sulfate that can strip the scalp of oils. While it’s important to maintain some of the natural oils on your scalp (as opposed to using harsh shampoos that will strip them completely dry), you don’t want to let these natural oils to build up over time. This, she explains, will disrupt the balance of your scalp, and leave it inflamed, itchy, sore, and flaky.

The answer to avoiding this issue isn’t by washing your hair more, though—it’s by ensuring that you wash it the right way whenever you do decide to wash.  “People often overlook the nape area at the very bottom of the back of the head as well and the sides of the head above the ear,” says Reslan, which can cause flaking and irritation.

That said, when you’re using a sulfate-free product and washing less frequently than every day, you’ll want to be sure to use mechanical scrub tactics (aka your own hands or a scalp brush) to really get into the nitty gritty. If you’re using a gentle shampoo that won’t lather on its own (which is the case for sulfate-free products, which are missing a lathering agent), the more pressure you’ll want to apply to get it deep into your scalp—otherwise you run the risk of leaving behind excess dirt and grime. “You should focus the shampoo on your roots and massage gently in circular motions to truly help remove build-up,” says Reslan, adding that you only really need to shampoo your ends if you regularly use styling products. Then, follow up with a conditioner on your mid-lengths and ends. This way, your skin and strands will be left feeling clean and build-up free.

Ever wondered what a scalp looks like under a pro-grade microscope? Check out the video below to see what happened when one of our staffers tried it for herself during a “scalp facial.” Warning: It was *disgusting.*

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