How to protect hair from chlorine

Wet your hair with clean water before you get in, coat it with a leave-in barrier or a pre-swim cream, put a cap over it if you own one, and rinse with fresh water the moment you get out. That is the whole routine. It takes about five minutes at the pool and it is the difference between swim hair that feels like hair and swim hair that feels like straw.

Here is why each step is there, and what to use.

What chlorine actually does to hair

Chlorinated water strips the natural oils that coat each strand and roughens the cuticle, the layer of overlapping scales on the outside of the hair. Without that coating, hair dries out, tangles, breaks at the ends and lets color fade faster. If your hair is bleached, highlighted, fine or already a bit damaged, it is more porous, so it takes up pool water faster and shows the effects first.

The green tint that blonde swimmers dread is a separate thing. It is not chlorine. It comes from copper and other metals in the water. Chlorine oxidizes the copper, and that oxidized metal clings to light, porous hair. Some pools do it and some never do, because pool chemistry varies.

Both problems start the same way: pool water gets into the hair. So the routine is built around letting less of it in.

The routine

1. Soak your hair with clean water first. Use the pool shower or a water bottle. Hair takes up water like a sponge, and hair that is already full of clean water takes up less of the pool. It does not block the pool water. It reduces how much gets in, which is most of the battle.
2. Coat it. On damp hair, work a barrier product through from mid-length to ends, where hair is oldest and most porous. A leave-in conditioner works. A natural oil works, although it is messy on a cap and heavy on fine hair. A product made for this job works best because it was formulated to stay on in water. AQUA GUARD Pre-Swim Hair Defense is made for exactly this. The directions on the bottle: dampen hair, apply a generous amount paying attention to the ends, give it three to five minutes to absorb, then swim. It is $24.99 for a 5.3 oz bottle on Amazon, where it has 4.4 stars across 3,364 ratings, and the listing's own words are that it "stops chlorine damage before it starts" and "prevents green hair; protects natural color".
3. Put a cap on if you have one. A silicone cap keeps most of the water off your hair. Not all of it. Water gets in around the edges, which is why the cap goes over coated hair rather than instead of coating it.
4. Rinse the second you get out. Fresh water from the pool shower takes a lot of what is sitting on the surface off before it dries in. Do not skip this because you are heading home to shower. Dried-in pool water is the version that does the damage.
5. Wash with a swimmers' shampoo and condition. A shampoo made for swimmers is formulated to lift chlorine and metal residue that a rinse leaves behind. AQUA GUARD Chlorine Clarifying Shampoo is $17.99 for 9.5 oz. Follow with a conditioner to put moisture back. If you swim most days, make one wash a week a deep conditioner or mask.

If you swim every day

Daily swimmers are the people this routine was written for. Skipping the barrier on a one-off pool party costs you a day of frizz. Skipping it five mornings a week for a season is how hair ends up brittle enough to snap when you brush it. The 16.9 oz Family Size bottle of Pre-Swim Hair Defense ($36.99) exists because of lap swimmers and swim-team parents, and a frequent swimmer should expect to run through the 5.3 oz bottle in a few weeks.

The order matters more than the brand. Wet, coat, cap, rinse. Do it in that order every time and the shampoo has a much smaller job.

Questions people ask

What can you put in your hair to protect it from chlorine?

A leave-in conditioner, a light natural oil such as coconut or argan, or a pre-swim product like AQUA GUARD Pre-Swim Hair Defense. Whatever you use goes on damp hair before you get in, with extra on the ends.

How do I protect my hair without a swim cap?

Do everything else. Soak with clean water, coat generously, tie long hair in a braid or bun so less of it floats in the water, and rinse immediately when you get out. A cap helps, but the pre-soak and the barrier do most of the work.

Do swim caps keep chlorine out of hair?

They keep most of the water off. They do not seal. Expect damp edges and the hairline to get wet, and treat the cap as one layer, not the only one.

Does chlorine really damage hair?

Yes. It strips the oils that protect the strand and roughens the cuticle, which shows up as dryness, tangling, breakage and faster color fade. Frequent exposure makes it worse; a single swim is not the problem.

Does this work for salt water too?

The routine does. Salt water pulls moisture out of hair and leaves salt behind as it dries, so you get the same dry, tangled result by a different route. Soak, coat, rinse.

What about kids?

Kids' hair is often finer and more porous than adult hair, and kids swim more days in a row in summer. Same routine, and the comb-out afterwards is the step parents fight over. AQUA GUARD makes a Pre-Swim Hair Defense For Kids ($21.99 for 8.45 oz) that the listing describes as a "chlorine hair shield" with "easy comb-through".