Why Does Chemotherapy Cause Hair Loss?

Mother Reading a Book to her Daughter
Christopher Futcher/Getty

Hair loss is a common side effect of chemotherapy treatment. It generally starts to happen a few weeks after chemotherapy starts. For most people, regrowth begins not long after chemotherapy treatment has ended. Not all people will lose their hair to chemotherapy, however.

Why Chemotherapy Causes Hair Loss

Cancer cells divide very quickly — at a much higher rate than most of the cells in our body. Chemotherapy drugs work by targeting these rapidly dividing cancer cells. Some cells in our bodies also rapidly divide, like our hair follicle cells and the cells in the lining of our stomach and digestive tract. Chemotherapy drugs simply cannot tell the difference between these normal, rapidly dividing cells and cancer cells, so the drug attacks these cells as well.

Some of the newer cancer drugs are more precise in targeting cancer cells. This is why some people do not experience chemotherapy-induced hair loss. There are varying degrees of hair loss, regardless of chemotherapy drug type and regimen. Some people will only experience thinning of the hair, while others will suffer from complete hair loss. This can also be related to the dosage of chemotherapy. Lower dosages of chemotherapy sometimes equate to lesser side effects, meaning little or no hair loss. Everyone responds to chemotherapy differently.

How Hair Loss Starts After Chemo

Hair loss usually doesn’t happen immediately after chemotherapy. Instead, it may start after a few treatments. Hair may fall out in clumps or seem like it is thinning. Some people choose to shave their heads, since any hair that remains can be dull and dry after treatment.

You can lose the hair on your head from chemotherapy, but also on all parts of your body, including the eyelashes and eyebrows, arm, legs, underarms and pubic area.

If you experience hair loss, you will almost always experience a regrowth after the treatment period is over, though the new hair may be a different color or texture.

What You Can Do to Ease the Experience

Aside from the loss of hair, chemotherapy treatment can leave the scalp and skin feeling tender, dry, itchy, or all of these. It may be helpful to take the following steps to help prevent or ease skin irritations associated with hair loss:

  • Keep your scalp clean by using mild shampoos and conditioners.
  • Brush any remaining hair with a soft-bristled hairbrush.
  • If you must use a hair dryer, use a low heat setting.
  • Consider using a gentle cream or lotion on your scalp if needed.
  • Avoid using brush rollers to curl or set hair.
  • Don’t dye your hair or get a perm, since hair dyes contain chemicals that can damage hair (though there is no research that supports chemicals being bad for hair, most doctors still recommend not coloring hair until about six months after hair regrows).
  • Consider a short haircut: shorter styles can make hair look thicker and fuller.
  • Protect your scalp from the sun by using sunscreen, a hat, a scarf, or a wig.
  • Try sleeping on a satin pillowcase to protect hair from breaking.
  • A gentle massage may be soothing for the scalp.
Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • American Cancer Society."A guide to Chemotherapy."