Does Dirty Hair Grow Faster? Debunking the Myth

Whether you’ve read about the “no-poo” movement, or seen a dubious TikTok about natural hair growth hacks, you’ve probably heard the rumor that washing your hair too often causes hair loss. But is this true? And does dirty hair grow faster?

In short, there’s no research to suggest that dirty hair grows faster, or that washing your hair leads to hair loss. The first claim doesn’t make much sense: Hair growth happens at the scalp level, and not in the strands themselves.

In fact, skipping washes for too long could actually harm your scalp, since a healthy scalp is essential for healthy hair growth.

Let’s dive into the facts about hair growth, scalp care, and whether you should reconsider your hair-washing habits.

The short answer? No.

Hair growth is influenced by many factors — genetics, hormones, overall health, and nutrition — but not how often you wash your hair.

Every hair follicle on your scalp has its own growth cycle, and your hair typically grows about half an inch per month, regardless of how often you shampoo.

Skipping washes won’t change this biological process, but it can lead to scalp conditions, which indirectly slows down hair growth. You need a clean, healthy scalp to support hair growth.

You might have noticed that your hair falls out more on wash days. When you comb your hair or look down at your shower drain, you might find a clump of hair there. What gives?

This is pretty common — when we lather on shampoo or comb our hair, we’re literally loosening hair strands that have already detached from our hair follicles. Plus, if you handle your hair roughly, you might also break hair strands, which can look a lot like hair fall.

This doesn’t mean that shampoo causes hair loss — just that you’re more likely to actually notice hair shedding on wash days. And some hair shedding is completely normal — it’s a part of the hair growth cycle.

If you are experiencing hair loss, though, here’s what could be to blame:

• Male pattern hair loss. Also called androgenetic alopecia, this common form of hair loss happens when a hormone called dihydrotestosterone (or DHT) shrinks your hair follicles. It’s mostly caused by genetics.

• Telogen effluvium. A temporary type of hair loss, telogen effluvium is caused by a sudden shock to the body — like a trauma, weight loss, surgery, severe illness, or a nutritional deficiency.

• Alopecia areata. Alopecia areata causes patches of complete hair loss. It’s an autoimmune disease, which happens when the body’s immune system attacks your own hair follicles.

• Traction alopecia. Your super-tight ponytail, man bun, or braids can put stress on your hair follicles, causing a type of hair loss called traction alopecia.

• Medical conditions. Some medical conditions can cause hair loss, such as psoriasis, syphilis, or thyroid disease. A fungal infection like ringworm (tinea capitis) can also cause hair loss. Hair loss can sometimes be a side effect of certain medications.

Word to the wise: Most forms of hair loss are progressive, meaning they get worse over time. This means you’ll want to treat hair loss as soon as you start to notice it.

We’d strongly suggest speaking with a healthcare professional — like a GP or a dermatologist — when you notice the early signs of balding, like thinning hair. A professional can help you identify the cause of your hair loss and possible treatment options.

While occasional missed washes won’t cause serious issues, long-term buildup of oil, dirt, and product residue can affect your scalp and hair in several ways. Let’s look at the harms of not washing your hair below.

1. Increased Dandruff and Scalp Irritation

Skipping washes allows Malassezia, a type of yeast that naturally lives on your scalp, to thrive. This can lead to itchiness, flakes, and even seborrheic dermatitis (a more severe form of dandruff).

Even if you don’t develop dandruff, a dirty scalp can get irritated and inflamed. Excess oil, dead skin, sweat, and even hair products can build up on your scalp, causing irritation. In some cases, this can lead to folliculitis (inflammation of hair follicles).

While dandruff doesn’t cause hair loss directly, it can create a less-than-ideal environment for new hair growth. Itching and inflammation can damage the skin barrier, affecting hair growth, and possibly leading to scalp infections.

2. Unpleasant Odor and Greasy Buildup

Your scalp produces sebum (natural oil) to protect and nourish your hair, but too much can make your hair look greasy, flat, and — let’s be honest — a little funky-smelling.

And, no, dry shampoo isn’t the solution here. While it can help absorb excess oil between washes, it doesn’t actually get rid of greasy buildup, so you’ll still need to wash your hair properly every so often.

Greasy hair also tends to be harder to style.

3. Hair Breakage

While natural oils help moisturize hair, excessive oil doesn’t equal stronger hair. In fact, dirty, unwashed hair can become heavy with buildup, making it more prone to breakage.

Oily hair can also become matted and knotty, and it can be difficult to detangle those knots without washing your hair. In addition to being painful and unsightly, these knots can lead to breakage.

If you’re worried about washing too often but also don’t want to walk around with a greasy scalp, here’s how to find the right balance.

1. Wash Based on Your Hair Type

How often should you wash your hair? This answer will depend entirely on your hair type and texture.

• Oily hair: Wash every second day to prevent buildup.

• Normal hair: Wash every second or third day to maintain balance.

• Dry, coily, or curly hair: Wash once or twice a week or as needed, since natural oils take longer to travel down curly strands.

Adjust your wash day schedule as needed — if your hair is too dry, wash it less often; if it gets too oily, wash it more often. Most people don’t need to wash their hair on a daily basis.

2. Use a Gentle, Sulfate-Free Shampoo

It’s also important to choose a shampoo that suits your hair type. If you’re concerned that you’re washing your hair too often, you’ll definitely want to avoid harsh formulas.

Opt for a gentle shampoo that cleanses without over-drying your scalp. Try to look for a sulfate-free formula. Sulfates can be harsh and stripping, especially for dry hair.

When shampooing your hair, focus on your scalp and the roots of your hair, as these areas are where oil builds up.

3. Don’t Skip Conditioner

A big hair care mistake that most guys make? Skipping the conditioner.

A quality conditioner helps restore moisture and strengthen hair, especially after cleansing. It helps combat dryness and makes your hair softer and easier to manage.

Focus on applying it to the mid-lengths and ends rather than the scalp to avoid excess oil buildup.

If you’re struggling with extra dry hair, nourishing treatments might make a difference. Consider trying a leave-in conditioner, a hair mask, or hair oils (like coconut oil) once a week or so.

4. Try a Scalp Scrub or Clarifying Shampoo

As mentioned, a healthy, clean scalp is essential for healthy hair growth. If you’re dealing with buildup or an oily scalp, using a clarifying shampoo or scalp scrub can help remove residue and keep your scalp fresh.

But use these treatments sparingly. Once a week is usually enough for most hair types.

Learn more in our guide to scalp exfoliation.

5. Be Gentle

Your hair is more prone to breakage when it’s wet, so be extra gentle when handling your hair on wash day.

Here are some tips:

• Avoid brushing it harshly. Use a wide-tooth comb on damp hair.

• Don’t rub it with a towel to dry it. Rather pat it dry until it’s damp, and then let it air dry.

• Use alcohol-free styling products. If you use gels, pomades, or hair mousse, opt for  a gentle, alcohol-free formula.

• If you heat style your hair, use a low or medium heat setting on your hair dryer or straightener. Use a heat protectant spray.

Good haircare habits can help minimize breakage, which can keep your hair looking lush, full, and healthy.

Learn more in our guide to hair care for men.

Since leaving your hair dirty won’t speed up growth, what will?

Here are a few things that actually support healthy hair growth:

• Minoxidil. Topical minoxidil is an FDA-approved hair loss treatment that is available over the counter. It’s clinically proven to stimulate hair follicles and promote growth. It’s available as a foam formulation or a liquid solution.

• Finasteride. Another FDA-approved treatment, finasteride (generic Propecia^®) is a prescription medication that helps reduce DHT levels, slowing male pattern hair loss.

• A combo treatment. For added effectiveness, consider using minoxidil and finasteride together. We have a 2-in-1 minoxidil and finasteride spray for boosting hair growth.

• DHT-blocking shampoos. Some hair loss shampoos contain ingredients that block DHT — for example, our thickening shampoo contains saw palmetto, which may block DHT.

• Hair growth supplements. If your hair loss is caused by a nutritional deficiency, a supplement like our biotin gummy might help. However, most of your nutrients can come from eating a healthy diet.

Not sure which treatment to start with? Speak with a healthcare professional. They can help you choose a treatment that makes sense for you.

Healthy lifestyle practices can support healthy hair growth, but they generally can’t help you regrow hair if you have a hair loss condition. If you want to learn more, we have a guide to natural hair growth tips plus a list of the best foods for hair growth.

Nope. For the sake of your hair health, scalp, and everybody who has to smell you, please wash your hair!

While skipping the occasional wash is totally fine, going too long without washing can lead to scalp buildup, irritation, and even hair thinning.

Keep this in mind:

• Dirty hair does NOT grow faster. And washing your hair doesn’t cause hair loss. Hair loss is determined by genetics, hormones, and health.

• Washing your hair is actually good for hair growth. A healthy, clean scalp is essential for strong hair, and excessive buildup can block follicles.

• At the same time, you don’t want to wash your hair too often. Overwashing can strip your natural hair oils, leaving your strands dry and fragile. So, you’ll want to find a washing routine that suits your hair type.

If you’re experiencing hair loss, you’re not alone — and it’s important to know there are treatments out there that actually work, like minoxidil and finasteride. Consider talking to a healthcare provider for some expert-backed hair growth advice.