Does Dirty Hair Really Grow Faster Than Clean Hair?

Iman curly hair

Lars Niki / Getty Images

The idea that hair grows faster when it's dirty is one of those myths surrounding black hair that won't go away. While the concept of never wetting your hair again is outrageous, there is actually some merit to this myth. So what's the truth about dirty hair and growth?

Fact: Hair needs to be cleansed, preferably regularly. Never putting water on your hair is unsanitary and can lead to odor, buildup, and even dryness and breakage.

With that out of the way, it's important to address why the notion of dirty hair promoting hair growth is still so prevalent. As you probably know already, black hair doesn't require the same frequent cleansing that naturally straight hair needs. You can shampoo once a week and still easily have healthy locks. The days of believing that once-monthly washes are sufficient, however, are over.

Disclaimer: This "never washing" idea does not include co-washing. The co-wash process includes plenty of water, and even women who steer completely clear of traditional shampoos can have clean, healthy locks.

Why, Though?

Part of the reason why black people of yesteryear didn't shampoo as often (or go swimming) is because—before relaxers and even after they hit the mainstream haircare market—the primary method for hair straightening was by using a hot comb. After spending several hours shampooing, drying, and straightening the hair with a hot comb—which can cause severe burns to the scalp—it's no wonder they wanted their hairstyles to last as long as possible.

Then, other people just aren't as adept at caring for their mane. They wait for their stylist to cleanse and condition their hair, and if their beautician is booked solid for the next four weeks, they wait until they're available. We get it, but taking your hair into your own hands is essential for its health. 

One of the reasons some people believe dirty hair promotes growth is because too-frequent washing encourages dryness, brittleness, and breakage—all of which happen to be some of the same issues you may face by not washing enough. If you shampoo too often (for black hair, too often could be daily with a harsh, sulfate-laden cleanser), yes, your hair will dry out and break. Anyone's hair will become damaged if they shampoo every day. But the alternative (never washing) isn't suitable, either. Natural oils, hair products, sebum from your scalp, and even air pollution all build up on your hair. Think about what happens then when you never wash it out or only wash once a month or so. The gunk isn't helping where growth is concerned.

Once or twice a week, shampoo with a gentle product on a regular schedule to keep the scalp clean and healthy.

Hair grows an average of 1/4 to 1/2 inch per month, although some people may notice more growth when they cleanse their tresses and scalps more often than they did in the past. The more you moisturize your hair and scalp with water, the healthier your head will be. Hair growth flourishes from a clean, healthy scalp.

The bottom line is that dirty hair doesn't grow any faster than clean hair, so you may as well have a clean scalp and fresh tresses. Your strands will look better, feel better, and be healthier, too.

Ahead are three of our all-time favorite shampoos for hair growth. These shampoos are so good that you'll wonder why it took you so long to cleanse your hair regularly. 

biotin shampoo
Maple Holistics Biotin Shampoo $10
Shop

Biotin, or vitamin B-7, is the super ingredient that is known for stimulating both hair and nail growth. This affordable shampoo from Maple Holistics gets rid of pesky dandruff, promotes hair growth, and helps to strengthen hair strands. Be sure to follow-up with your favorite hair mask for extra hydration. 

Davines NaturalTech Shampaoo
Davines Energizing Shampoo $32
Shop

Massage Davine's caffeine-infused shampoo into your scalp to help stimulate hair growth and prevent hair loss. Your strands will be left shiny and clean after rinsing out this paraben and sulfate-free shampoo. 

oribe shampoo
Oribe Gold Lust Repair & Restore Shampoo $49
Shop

Yes, this nearly $50 shampoo is a splurge, but it is certainly worth it if you crave supermodel-worthy hair. The brand's signature blend—watermelon, lychee, and edelweiss flower extracts—prevents your dye job from fading and smells as delicious as you could imagine. Mediterranean cypress extract, argan, and maracuja oil tame frizz and replenishes your dry, thirsty strands.

Related Stories