Swimming, chlorine and your hair

Swimming is excellent exercise, and in a hot country like Malaysia a pool can be the most pleasant place to be. But many regular swimmers notice their hair becoming dry, tangled, rough or lighter in colour. Some worry that chlorine is making their hair fall out. This guide explains what pool water does to hair, what it does not do, and how to protect your hair without giving up swimming.

What chlorine does to hair

Pool water is treated with chlorine to keep it safe. The AAD notes that pool chemicals can be hard on your hair ¹.

One of the clearest studies looked at 67 elite swimmers from the Japan National Swimming Team and 54 people of the same age who did not swim ²:

• 61% of the swimmers had hair discolouration, compared with none of the non-swimmers.
• Under the electron microscope, the swimmers' discoloured, golden hair had completely lost its cuticle, the protective outer layer of the hair.
• The pigment granules (melanosomes) inside the hair were fewer and smaller, and chlorine was found inside them.
• The discoloured hair contained less sulfur, a building block of hair protein.

The researchers concluded that the discolouration was mainly due to cuticle damage from friction with water, which allowed chlorine compounds in the pool water to reach the inner hair and break down its pigment ².

These were elite swimmers who trained for many hours. Most recreational swimmers will see much milder effects, but the process is the same.

Does swimming cause hair loss?

The research points to damage of the hair shaft, the part you can see, not the follicle that grows the hair. In the Japanese study, a test of the hair bulbs found no significant difference between swimmers and non-swimmers ².

That said, damaged hair is fragile and tends to break. The AAD explains that if we keep damaging our hair, we may eventually see thinning or even bald spots ¹. Breakage can look like hair loss. See hair breakage vs hair loss.

If you are losing hair from the root, or have bald patches, swimming is unlikely to be the main cause. See sudden severe hair fall.

Protecting hair before and after swimming

The AAD gives these recommendations for swimmers ¹:

• Wear a swim cap.
• Rinse your hair immediately after swimming.
• Wash with a swimmers' shampoo, one made to remove pool chemicals, and follow with a deep conditioner.
• Dry your hair promptly, and use shampoo and conditioner after swimming.

A few other habits from the AAD's general hair care advice also help ^{1 3}:

• Use conditioner after every shampoo.
• Wrap your hair in a towel to absorb water instead of rubbing it.
• Comb gently with a wide-tooth comb. If you have straight hair, let it dry a little first. If you have curly hair, comb while it is damp.
• Let your hair air dry when possible, or use the lowest dryer setting.

Wetting hair before you swim

Many swimmers wet their hair with clean tap water before getting in the pool, on the idea that hair already full of water will absorb less pool water. We could not find a study testing this, but it is low risk and many people find it helps.

Sun and swimming

Outdoor pools add sun exposure. A study of Indian women found that sun exposure of more than 3 hours was linked to microscopic changes in the hair ⁴. The AAD suggests protecting hair in the sun with a wide-brimmed hat or a leave-in conditioner containing zinc oxide ¹.

Coloured or chemically treated hair

Hair that has been coloured, bleached, permed or relaxed is already more fragile ¹. Pool water adds more stress. If you colour your hair and swim often, a swim cap and a thorough rinse are especially worthwhile. See hair dye and hair loss.

Hygiene at the pool

Swimming pools and changing rooms are shared spaces. Scalp ringworm can spread through shared items such as hairbrushes, towels and hats ⁵. Bring your own towel, cap and comb. See tinea capitis.

How often should swimmers wash their hair?

If you swim several times a week, you will probably wash after each swim. Research in Asian adults found that frequent washing, even daily, did not cause objective harm to the hair ⁶. Focus the shampoo on your scalp, and always condition afterwards ³. See how often to wash hair.

When to see a doctor

Hair that is dry and rough from swimming usually improves with better care and time. See a dermatologist if ¹:

• Changing your hair care does not help
• You are worried about thinning hair or hair loss
• You have bald patches, a sore scalp or a rash

The bottom line

Chlorinated water and friction can strip the cuticle, dry the hair and change its colour, as seen in elite swimmers. This damages the hair strand rather than the root. A swim cap, a prompt rinse, a shampoo and conditioner after swimming, and gentle drying and combing go a long way. Keep swimming, and look after your hair afterwards.

Frequently asked questions

Does chlorine make hair fall out?

Research on swimmers points to damage of the hair shaft, not the root ². Damaged hair can break, which may look like thinning ¹.

Why does my hair turn lighter from swimming?

A study of elite swimmers found cuticle damage let chlorine reach the inner hair and break down pigment ².

How can I protect my hair when swimming?

The AAD suggests a swim cap, rinsing straight after swimming, a swimmers' shampoo and a deep conditioner ¹.

Is it okay to wash my hair after every swim?

Yes. A study in Asian adults found frequent washing did not cause objective harm ⁶.

Educational content. Not medical advice.