Frizzy Hair: Why It Happens & How to Finally Tame It

Frizz happens because the outer layer of your hair is open instead of flat, which lets humidity sneak in and makes individual strands swell unevenly. Understanding your hair's porosity is the key to actually fixing it, because what works for one hair type can make things worse for another.

What Actually Causes Frizz?

Your hair shaft has an outer layer called the cuticle, made up of tiny overlapping scales, a bit like roof tiles. When those scales lie flat, your hair looks smooth and shiny. When they're raised (by humidity, damage, dryness, or rough handling), moisture seeps into the shaft unevenly, and individual hairs swell and puff at different rates. High humidity is a constant trigger, but damaged or over-processed hair frizzes even in dry air because the cuticle is no longer intact. Picking the wrong products is a big contributor too: heavy products on fine hair, or products that are too light for very dry or damaged hair, both make things worse.

What Is Hair Porosity and Why Does It Matter?

Porosity describes how easily your hair takes in and holds on to moisture. It's the most useful thing to understand about your own hair type, because it determines which products will actually work for you. Low porosity hair has tightly closed scales that resist absorbing moisture, so products tend to sit on top rather than soak in. High porosity hair has open or damaged scales that absorb moisture fast but lose it just as quickly, causing constant frizz and dryness. Normal porosity is the balance in the middle. A simple home test: drop a few clean hairs into a glass of water. If they float after a minute or two, porosity is low. If they sink almost straight away, it's high.

What to Do at Home

The way you dry your hair makes more difference than most people realise. Blot with a microfiber towel or a cotton t-shirt; rubbing with a regular towel physically lifts the cuticle scales and creates frizz before you've even touched a product. A cool or cold rinse at the end of your wash helps close those scales before you step out of the shower. Apply your leave-in conditioner or anti-frizz cream to damp hair while it can still absorb the product. And then, the hard part, don't touch your hair while it's drying. Every time you handle damp hair, you disturb the cuticle and invite more frizz.

What Products Help (and What to Skip)

Ingredients that genuinely help: glycerin, argan oil, and shea butter. For high-porosity hair, products with protein (like keratin or silk amino acids) help rebuild the cuticle. What to steer clear of: drying alcohols. Look for "alcohol denat." or "isopropyl alcohol" near the top of the ingredient list and put it back on the shelf. Silicones create smooth-looking hair in the short term but build up over multiple uses, eventually making hair heavier and frizzier. If you use silicone-based products, a clarifying shampoo once a month clears the buildup.

What the Salon Can Do

For persistent frizz, a keratin smoothing treatment is the most effective option, and it places a protective layer over the cuticle that lasts 3 to 5 months. Hair Botox (nothing to do with the cosmetic injection) is a deep conditioning treatment that fills gaps in the cuticle and adds smoothness without changing your natural texture or curl pattern at all. Olaplex is the one we reach for when damage is the root cause, since it rebuilds broken bonds inside the hair shaft. And if your frizz is mainly from dryness, a professional deep conditioning treatment followed by a blowout can reset your hair for several weeks.