Chemotherapy and hair loss: what to expect and scalp cooling

For many people facing cancer treatment, losing their hair is one of the hardest parts. It is a visible change at a time when so much else feels out of control. Knowing what to expect can make it a little easier to prepare.

Why chemotherapy causes hair loss

Chemotherapy works by attacking cells that divide quickly, such as cancer cells. Hair follicle cells also divide very quickly, so they are often affected too. The type of hair loss this causes is called anagen effluvium, meaning the shedding of hairs that are actively growing ¹.

DermNet notes that chemotherapy drugs are especially likely to cause hair loss when several drugs are used together or at high doses. Severe hair loss has been reported with drugs such as doxorubicin, the nitrosoureas and cyclophosphamide ¹.

Not every chemotherapy medicine causes hair loss, and the amount varies from person to person, even on the same drugs ². The NHS lists temporary hair loss among the possible side effects of chemotherapy ³. Your care team can tell you how likely it is with your treatment plan.

When does it start?

• Hair loss usually develops within 2 to 4 weeks of starting chemotherapy ¹
• In a study of women having chemotherapy for breast cancer, the average time from starting treatment to hair loss was 4 to 5 weeks, though for some it began as early as 2 weeks ²
• It can be rapid. Up to 90% of scalp hair may be lost over a period of weeks ¹

Hair loss mostly affects the scalp, but eyebrows, eyelashes and other body hair can also be lost ¹.

Scalp cooling: what the evidence shows

Scalp cooling uses a cold cap worn before, during and after each chemotherapy infusion. Cooling the scalp reduces blood flow around the hair follicles, so less of the drug reaches them. DermNet describes it as the most effective treatment so far to reduce hair loss from chemotherapy. The cap is usually worn for about 30 minutes before the infusion, during it and for 90 minutes afterwards ².

The best-known trial is the SCALP randomised clinical trial, published in JAMA in 2017 ⁴:

• It included women with stage I to II breast cancer receiving taxane or anthracycline chemotherapy, or both
• Success was defined as losing less than half of their hair, not needing a wig, after 4 cycles
• At the interim analysis, 48 of 95 women (50.5%) who used scalp cooling kept their hair by this measure, compared with none of 47 women who did not
• Side effects from the device were mild to moderate, with no serious device-related events. The authors said more research is needed on longer-term results

So scalp cooling roughly gave half of these women a good result. It does not work for everyone, and results may differ with other cancers and drug combinations. It may not be suitable for every cancer or treatment, so ask your oncology team whether it is an option for you and whether it is available at your hospital.

Practical ways to prepare

• Consider a shorter cut before treatment starts. Some people find it less upsetting to see short hairs fall than long ones
• Choose a wig, scarf, tudung or cap early, while you still have your hair, so you can match colour and style if you wish. See scalp care for women who cover
• Be gentle: use a mild shampoo, a soft brush, and avoid heat styling, colouring and tight styles while hair is fragile
• Protect the scalp: a bare scalp can burn in the Malaysian sun, so cover it outdoors and keep it moisturised
• Ask about eyebrows: DermNet lists cosmetic camouflage for eyebrows as one option ¹
• Talk about it: hair loss can affect body image and mood. Your care team and cancer support groups can help

Will my hair grow back?

For most people, yes. DermNet describes chemotherapy-related anagen effluvium as reversible: the follicle resumes normal activity once the drug is stopped, and hair has fully grown back 3 to 6 months after chemotherapy in most cases ¹. Sometimes hair even starts to grow back before chemotherapy has finished ¹.

New hair may look different at first. Sometimes people with straight hair notice curly hair when it grows back, and the colour may change ¹. These changes often settle over time.

Radiotherapy is different

Radiotherapy to the head can also cause hair loss. DermNet notes that after radiation to the scalp, hair may grow back incompletely or not at all ¹. Ask your team what to expect for your specific treatment.

Can anything help hair grow back faster?

DermNet lists topical minoxidil as one suggested treatment for anagen effluvium ¹. Check with your oncology team before using any product on your scalp during or after treatment. Most people simply need time.

When to tell your care team

• Your scalp becomes red, sore, broken or infected
• Hair has not started to grow back several months after treatment finished
• Hair loss is affecting your mood or your willingness to continue treatment

The bottom line

Chemotherapy often causes hair loss, usually starting 2 to 4 weeks into treatment. It is almost always temporary, with hair growing back in most people within 3 to 6 months of finishing. Scalp cooling helped about half of the women in one major trial keep most of their hair, but it is not right for everyone. Talk to your care team early about your options and how to prepare. See medicines that can cause hair loss.

Frequently asked questions

When does hair fall out after chemotherapy?

Usually within 2 to 4 weeks of starting chemotherapy ¹.

Does scalp cooling work?

In the SCALP trial, 50.5% of women with breast cancer who used scalp cooling kept more than half their hair, versus none without it ⁴.

Will my hair grow back after chemotherapy?

In most cases, yes. Hair has usually fully grown back 3 to 6 months after chemotherapy ¹.

Can my hair grow back different?

Yes. Straight hair sometimes grows back curly, and the colour may change ¹.

Educational content. Not medical advice.