How to Protect Hair From Chlorine: Before, During and After a Swim

What chlorine does to hair

Chlorine strips the natural oils that coat the hair and weakens its protein structure, which leaves hair dry, rough and more likely to break. The American Academy of Dermatology describes chlorine dissolving the lipids that protect the hair shaft, so the hair is more exposed to damage and split ends.

One swim will not ruin anyone's hair, but regular swimmers notice it fast: hair feels like straw, tangles easily, and short cuts lose their shape because the texture changes. Salt water at the beach is less harsh but dries hair in a similar way, especially combined with sun.

Before you swim: fill the hair with clean water

Soak your hair under the shower before you get in the pool. Hair works a little like a sponge; if it is already full of clean water, it takes up less chlorinated water.

Then add a barrier. Dermatologists suggest a leave-in conditioner or a light oil worked through the hair before swimming, which forms a physical layer between the hair and chlorine. Short hair needs only a small amount; longer or curly hair benefits from more.

1. Rinse your hair thoroughly with tap water in the change room shower.
2. Work a pea to coin-sized amount of leave-in conditioner or a few drops of oil through the hair.
3. Put on your swim cap while the hair is still damp.

During: why a swim cap still matters

A swim cap is the single most effective barrier against chlorine. It will not keep hair perfectly dry, but it dramatically cuts the amount of pool water moving through the hair during a session.

Silicone caps are the most comfortable and durable and are less likely to pull short hair than latex. Lycra or fabric caps are gentle but let more water through. For men with a very short fade or buzz cut, a cap may feel unnecessary, but it still protects the scalp and makes the post-swim rinse faster.

After: rinse, clarify, condition

Rinse your hair immediately after you get out of the pool, before chlorine has time to dry into the hair. Then wash with a shampoo made for swimmers, or a clarifying shampoo, which removes chlorine and minerals rather than just surface oil.

Finish with conditioner every time. The AAD recommends a deep conditioner after swimming to restore moisture; our page on whether men need conditioner explains how to use one on shorter hair. For regular swimmers, clarifying every swim can be drying, so alternate with a gentle shampoo; our guide on choosing a shampoo covers the options.

• Rinse within minutes, not after the drive home.
• Swimmers' or clarifying shampoo on the scalp, lather through the lengths.
• Conditioner on the lengths every swim; a mask once a week.
• Pat dry, do not rub.

Why light and grey hair turns green

The green tint that swimmers get is not from chlorine alone. It comes from copper, which can enter pool water from pipes or algaecides, and which chlorine helps bind to the hair. Blond, grey and white hair shows it most because there is no dark pigment to hide it.

Prevention is the same as for dryness: pre-wet, use a barrier, wear a cap and rinse quickly. If you already have a green tint, a swimmers' shampoo designed to remove minerals usually lifts it over a few washes. Grey-haired swimmers can also follow our tips on caring for grey hair.

Protecting skin and a fresh cut at the pool

A new fade or lineup exposes more skin, and chlorine plus sun can leave that skin tight and itchy. Rinse after swimming, moisturize, and if you swim outdoors in summer, put water-resistant sunscreen with SPF 30 or higher on bare sides and neck, reapplying after swimming.

Hot tubs deserve extra caution right after a close shave or haircut. Poorly maintained hot tubs are a known cause of folliculitis, an infection of the hair follicles; see a doctor or dermatologist if you develop itchy red bumps or pus spots after using one.