Frizzy hair: why it happens and how to tame it

Frizz is what happens when the strands in a section of hair stop lying together smoothly. Dry or damaged hair takes up moisture from the air unevenly, so some strands swell and bend while others don't. The aim is to keep hair moisturized, its surface smooth, and friction low.

Quick answer: To tame frizzy hair, condition every time you wash, add a leave-in, and finish with a smoothing cream or serum (silicones and film-forming polymers coat the surface). Blot hair with a T-shirt instead of rubbing with a towel. Use a heat protectant and lower heat. In very humid weather, go easy on products high in glycerin.

Why hair gets frizzy

Hair has a natural negative electrical charge, especially when it is damaged. Strands with the same charge push away from each other, which adds to flyaways. On top of that:

• Humidity. Hair takes up water from the air. When parts of a strand absorb more than others, the strand swells and kinks unevenly.
• Dryness and damage. A raised or worn cuticle (the outer layer of scales) lets water in and out quickly. This is called high porosity.
• Friction. A review of hair cosmetics names friction (attrition) as the main cause of frizz: rough towels, cotton pillowcases, and brushing dry curls all rough up the cuticle.
• Heat and chemical treatments. Bleach, color, relaxers and hot tools all wear down the cuticle over time. See heat damage.
• Natural texture. Wavy and curly hair often look frizzier, because curls separate easily and curved strands are harder to comb without roughing the surface.

How conditioners and smoothing products work

Conditioners carry a positive charge. They are attracted to the negative charge of hair, settle on the surface, and calm static and frizz. They also lubricate the cuticle, so strands slide past each other instead of catching.

Smoothing products add a thin, flexible coat on top:

• Silicones such as dimethicone and amodimethicone form a light film that adds slip and shine and helps protect the shaft from rubbing.
• Film formers are polymers that create a humidity-resistant layer. Products labeled "humidity resistant" often rely on them.
• Hydrolyzed proteins, which are proteins broken into small pieces, carry a positive charge and can cling to damaged areas, which may reduce frizz. They do not rebuild the hair's structure.
• Oils smooth the surface and add shine, especially on the ends.

The anti-frizz routine, step by step

1. Wash gently. Focus shampoo on the scalp and let the suds run through the lengths.
2. Condition generously. Apply along the lengths and ends every time.
3. Add a leave-in to damp hair. See leave-in products.
4. Smooth. Apply a cream or serum with silicones or film formers while hair is damp.
5. Blot, don't rub. Use a microfiber towel or a soft cotton T-shirt.
6. Dry carefully. Air-dry, or blow-dry with the nozzle pointing down the hair shaft. Use a heat protectant first, and low or medium heat.
7. Finish. A pea-sized amount of oil or serum on dry ends.

Glycerin and humidity

Glycerin is a humectant, which means it attracts water. In moderate humidity, it can keep hair soft and bouncy. In very humid weather, it may pull in extra water and make hair swell and frizz. In very dry air, there is little water to draw in. If your frizz changes with the weather, check whether glycerin is near the top of your leave-in or gel, and try a lighter formula on sticky days.

Frizz in curly vs straight hair

Quick fixes for frizz during the day

• Smooth a drop of serum or cream between your palms and press it lightly over the top layer of hair.
• For curls, mist with water, add a little gel to frizzy sections, and scrunch.
• Keep a satin scrunchie or clip handy for humid days, and tie hair up loosely rather than tightly.
• Avoid running your fingers through dry curls, which separates them and adds frizz.
• Wear a hat or scarf in strong sun or wind, which can dry hair out further.

Salon smoothing treatments: what to know

• Keratin and "Brazilian" smoothing treatments can smooth hair for weeks to months. Many contain formaldehyde or ingredients that release it when heated with a flat iron. The FDA says formaldehyde can irritate the eyes, nose and throat, cause coughing and wheezing, and trigger skin allergies, and it is classified as a human carcinogen. Look for formaldehyde, formalin or methylene glycol on labels, and ask your salon what the product contains. The FDA advises not buying a retail product that has no ingredient list.
• Permanent straightening (thermal reconditioning) breaks and resets the hair's internal bonds. It is permanent until the hair grows out and needs an experienced stylist.
• Glossing treatments give temporary shine and smoothness and are usually gentler.

What not to combine

• Bleach and straightening treatments close together: high risk of severe breakage. Ask your stylist to space them out.
• Heavy silicones without ever clarifying: build-up and limp hair, especially if your hair is fine.
• Brushing curly hair dry: more frizz and breakage.

How long until you see results

Smoothing products work right away. Frizz caused by damage usually improves over weeks to months, as healthier hair grows and damaged ends are trimmed. Your hair's natural texture won't change, but it can look much calmer.

When to see a dermatologist

Frizz on its own is a cosmetic issue, but see a dermatologist or doctor if:

• Hair suddenly becomes brittle and breaks off, or sheds in clumps
• You notice thinning or bald patches
• Your scalp becomes red, itchy, flaky or sore
• You have burning eyes, breathing problems or a skin rash after a salon treatment (also report it to the FDA)

FAQ

Are silicones bad for frizzy hair?

No. Silicones smooth and protect the hair surface and are among the most effective anti-frizz ingredients. If your hair starts to feel heavy, use a clarifying shampoo now and then.

Does a silk pillowcase help frizz?

It may. Silk and satin are smoother than cotton, so they create less friction overnight. Many people notice less morning frizz, though studies are limited.

Can a haircut help with frizz?

Yes. Trimming dry, split ends removes the most damaged, most porous part of the hair, which is often the frizziest.

Why is my hair frizzy right after washing?

Hot water, a stripping shampoo, skipping conditioner or rubbing with a towel can all rough up the cuticle. Try cooler water, more conditioner and blotting.

Sources

• Hair cosmetics: an overview (PubMed Central, NIH)
• Hair smoothing products that release formaldehyde when heated (US FDA)
• Effects of chemical straighteners on the hair shaft and scalp (PubMed Central, NIH)
• Tips for healthy hair (American Academy of Dermatology)
• The what, why and how of curly hair: a review (PubMed Central, NIH)