The Science of Healthy Hair Growth: What Actually Works (And What Doesn’t)

Everyone wants longer, stronger, healthier-looking hair, and the internet is full of advice on how to get it. Some of it holds up. Some of it does not. This guide sticks to what board-certified dermatologists say, and explains where a salon visit fits in.

What Actually Supports Healthy Hair

The American Academy of Dermatology (AAD) publishes hair care tips from board-certified dermatologists. Their advice centers on protecting the hair you have and keeping the scalp clean and comfortable.

• Know your hair type. The AAD says products and routines work best when they suit your hair, whether it is curly, straight, coarse, or fine.
• Shampoo to match your scalp. The AAD suggests washing based on how often your hair gets dirty or oily. Those with dry, textured, curly, or thick hair may shampoo less often.
• Apply shampoo to the scalp. This cleanses buildup, dead skin, and excess oil without drying out the length of your hair.
• Use conditioner after washing. The AAD says conditioner moisturizes and detangles, which makes hair easier to manage.
• Be gentle when wet. Hair is delicate when wet, so the AAD recommends a wide-tooth comb, starting at the ends and working upward.
• Protect hair from heat. The AAD advises limiting blow drying and hot tools, using low or medium settings, and using a heat protectant.

Growth Versus Breakage

Much of what looks like slow growth can be breakage. The AAD notes that damaged hair is fragile and tends to break, and that continued damage can eventually lead to thinning. Habits it lists as hard on hair include rubbing shampoo through the length of your hair, skipping conditioner, and rubbing hair with a towel. Wrapping wet hair in a towel instead is the AAD’s suggestion.

Hairstyles that pull can matter too. The AAD says frequently wearing tight styles such as buns, ponytails, or braids can cause traction alopecia, a type of hair loss from pulling on the hair.

Common Hair Growth Myths

Myth: A supplement will fix it.

The AAD notes that supplements marketed for hair growth are not regulated by the FDA for safety and effectiveness before they are sold. It also says getting too much of certain nutrients, including selenium, vitamin A, and vitamin E, has been linked to hair loss. It suggests finding out whether you are getting enough vitamins or minerals before taking a supplement, and a blood test can show that.

Myth: Washing less will stop hair from falling out.

The AAD mentions that some women scale back on how often they shampoo when they notice hair loss, and describes the results of efforts like this as often modest at best. A gentle shampoo that suits your scalp and hair type is the better route.

Myth: Any hair product will restore thinning hair.

The AAD says products that come with claims to restore hair rarely get to the root of the problem. Finding the cause comes first.

Nutrition and Hair

The AAD says that not getting enough of some nutrients, such as iron or protein, can lead to hair loss, and that eating too few calories every day can also cause significant hair loss. A balanced diet supports your overall health, and your doctor can tell you whether a deficiency is a concern.

When to See a Doctor

Hair loss has many causes. The AAD says what is causing it determines whether your hair can regrow on its own, needs treatment, or needs immediate care to prevent permanent loss. The most common cause worldwide is hereditary hair loss. The AAD recommends seeing a board-certified dermatologist for an accurate diagnosis, and says tests such as a blood test or scalp biopsy may be used when a disease, vitamin deficiency, hormone imbalance, or infection is suspected. A stylist can help with the care side of your hair, but cannot diagnose a medical condition.

How Your Stylist Can Help

A stylist can look at your hair’s texture and condition and help you build a routine around trims, gentler styling, and color services that respect your hair. If you color your hair, the AAD advises seeing a salon that specializes in the service you want, one whose professionals can examine your scalp and hair to find the product most suitable for you. Learn more about our hair color services.

Frequently Asked Questions

Do trims make hair grow faster?

A trim is not a growth treatment, because each hair grows out of a follicle in the scalp. Keeping length comes down to limiting breakage, and the AAD says conditioner coats strands, which reduces breakage and split ends.

How often should I wash my hair?

The AAD says it depends on how often your hair gets dirty or oily. People with dry, textured, curly, or thick hair may wash less often.

Should I take a hair growth supplement?

Talk to your doctor first. The AAD says too much of certain nutrients has been linked to hair loss, and supplements are not reviewed for safety and effectiveness before sale.

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