What Causes Swimmer's Hair?

The Science of How Swimmer's Hair Works

Chemicals in a swimming pool strip hair of its natural protection, making it susceptible to damage.
Chemicals in a swimming pool strip hair of its natural protection, making it susceptible to damage. Stefan Obermeier / Getty Images

Do you love swimming, but hate how it makes you hair dry, tangled, damaged, and possibly lighter or green? If so, your problem is swimmer's hair. Once you understand how swimmer's hair works, you may be able to prevent or correct it.

Question: What Causes Swimmer's Hair?

Swimming in a pool is great for your body, but hard on your hair! If you swim a lot and your hair has become dry and damaged, you may have a case of swimmer's hair. Here's a look at the causes of swimmer's hair and what you can do to prevent or treat it.

Answer: Science of Swimmer's Hair

It may seem strange that exposure to water could make your hair dry and damaged, but it isn't actually the water that causes the problem. Pool chemicals, especially chlorine and bromine, react with the sebum and oils that protect your hair, leaving the hair's cuticle exposed. This allows other chemicals to react with your hair, such as copper compounds, which can give your hair a greenish tint. Your hair also becomes more susceptible to damage from the sun's ultraviolet rays. The ultraviolet radiation breaks the bonds in keratin, the protein that makes up hair, causing roughness and split ends. Pigment molecules also succumb to pool chemicals and the sun, so even if your hair doesn't turn green, it can become lighter or faded.

Preventing Swimmer's Hair

The best way to prevent swimmer's hair is to keep the pool water from soaking into your hair. A swim cap will work for this. Limiting your hair's exposure also helps. You won't see much damage from the occasional dip in the pool, nor will you get damaged hair if you don't get your hair wet.

If you dislike using a swim cap, another strategy is to wet your hair with clean water before entering a pool or the ocean. Hair that is already saturated with water won't absorb more, so less damage will occur.

You can undo some damage and prevent further problems by showering after exiting the pool. It's best if you shampoo your hair, but even a quick rinse in fresh water will help remove the pool chemicals. Follow up with a conditioner to seal your hair's cuticle and replenish its protective coating.

Is Your Hair Damaged?

Healthy hair is less susceptible to swimmer's hair than hair that already has damage. If you have colored, permed or heat-treated hair, your hair is at greater risk for dryness and color loss from swimming than it would be if you had untreated hair. If you swim a lot, try to minimize hair processing and keep up your cut so that chlorine won't get in through split ends.

A Word About Special Shampoos

You can purchase a special shampoo made just for swimmers. These products typically contain ingredients that will chelate copper and other metals so that they won't discolor your hair. The shampoo may leave a waxy coating on your hair, which is intended to prevent it from soaking up pool water. You may wish to alternate this shampoo with a clarifying shampoo, to prevent build-up which can weigh your hair down and dull its shine. Another option is to use a regular shampoo and follow-up with a leave-in conditioner. A conditioner that contains a UV-filter is a nice choice because it will confer protection from both the sun and the pool. You may also want to save yourself some trouble and use a detangler after swimming.

Key Points

  • Swimmer's hair is hair that is dry, damaged, and possibly discolored due to exposure to chemicals in a treated pool or the ocean.
  • Copper is the main culprit behind the most damage. Copper compounds are used to prevent the growth of algae, microorganisms, and invertebrates.
  • Other chemicals that cause damage include bromine, chlorine, and salt (NaCl). Bromine and chlorine (including chlorine from salt) can react with hair, breaking bonds in its protein, keratin. Salt also strips oils from hair, making it dry.
  • Damage may be minimized or prevented by pre-treating with a product for swimmers, dampening hair with clean water before entering the pool or ocean, wearing a swim cap, and immediately rinsing hair upon exiting the water.
  • Some of the damage can be reversed by using conditioner or special products intended to treat swimmer's hair.