While you are likely fully stocked when it comes to shampoos and conditioners, there is one hair care essential that should make it onto your list: a shower cap. They provide a little extra care in-between wash days and can do much more than simply prevent hair from becoming wet. "If you're not wearing a shower cap on non-wash days, you're not protecting your hair," explains Maryse Butler, the brand communications manager at Shhhowercap. Plus, this tool can help you condition your hair when you are planning to wash it. Here, our experts explain the many perks of using a shower cap in your everyday routine.

Shower caps do more than simply shield hair from water.

Shower caps have always been used to stop your strands from getting wet, but Vinnie Ferrara, a Nioxin top artist, adds that this hair care tool can also prevent water and steam from breaking down already-applied products—which can deleteriously cause them to seep into your scalp. "Since the primary function of the scalp skin is to protect the glands and to eliminate toxins and debris from the body—like sweat, oil, and dead skin—it is important to keep these styling products off of it," he shares.

As for other benefits? Use them at night, say our experts, and you can even protect your hair when you sleep, as it limits friction and preserves styles. Their most basic function—to prevent wet hair—shouldn't be overlooked, either, since it helps you avoid over-washing and continuously aggravating any underlying issues. "During dry seasons like winter, clients share their scalp is dry and also sensitive," Diane Stevens, a Nioxin global stylist and the owner of the Cole Stevens Salon, says. "So, I recommend two things. First: Use a scalp-specific product—like Nioxin Scalp Relief System ($45.50, amazon.com)—with aloe to soothe the scalp and leave the hair feeling nourished." Next, she suggests not shampooing as often and wearing a shower cap, instead to avoid getting your hair wet while you wash your body.

"Having curly, textured hair often means that wash day is a big event that takes a lot of time and money," Butler explains. "Moisture from the shower causes frizz, destruction of style, ruined edges, and most importantly, actual damage to strands via breakage." A shower cap shields curl patterns from extra moisture and helps maintain straight styles, too. "I often share with my clients after styling a beautiful full blowout that the key is to make sure this gorgeous [look] does not get wet in the shower," adds Stevens.

Whatever your hair type, you want to make sure the shower cap you purchase fits properly and is made of reusable materials that are designed to last. "This is a product that you will be using, on average, five to six days out of the week," Butler says. "Even more so if you're additionally using the cap to mask or deep condition your hair on wash day. Longevity, quality construction, and ideally, [a style] you actually enjoy wearing are key." If you do opt to use a shower cap for a deep conditioning treatment, Stevens recommends keeping the mask—such as the Nioxin Deep Protect Density Mask ($21, amazon.com)—and cap on for about 30 minutes. "This will feel like a salon deep conditioning treatment to strengthen and moisturize your hair," she says. "Make sure you rinse your shower cap after and put in the washing machine with your towel and air dry (no dryer heat)."

Another expert tip? Ferrara suggests securing a stretchy headband over your hairline before situating your shower cap over it. "This will ensure no water or steam will get onto your hair while you shower," Ferrara shares. "After you shower, dry the cap first or even wrap your head loosely in a towel with the cap on. This will ensure the cap is dry." The stylist adds that you'll want to be sure that the covering remains on if the bathroom is steamy—as this type of moisture will impact your hair like regular water.