Chemotherapy drugs can cause hair loss. Cold caps can prevent it.

To gain FDA approval for marketing, chemotherapy drugs must have been tested and shown to be effective and reasonably safe. But of course, we all know they are not entirely benign. There are a lot of adverse effects, one of which is hair loss. Around 65% of people who get chemo will lose their hair. Some take it in stride, shaving the sparse remaining hair, wearing wigs, turbans, and colorful scarves, joking about it, and waiting patiently for the hair to re-grow, which it will do gradually over a period of months. Susan Gerbic, founder of Guerilla Skepticism on Wikipedia, demonstrated a great attitude and a great sense of humor: she took advantage of her temporary baldness to have friends draw a phrenology map on her scalp in preparation for a skeptical costume party. For others, because of vanity or self-image concerns, teasing, and the reactions of others, it can be terribly distressing, Fortunately, there is an effective remedy: cold caps.

The why and the how of scalp hypothermia

It makes sense to cool the scalp. Decreased blood flow can be expected to reduce the amount of chemo drugs absorbed by hair follicles, and colder hair follicles will be less active and less able to take up the drugs. Also known as scalp hypothermia, cooling can be provided by ice packs or by devices known as cold caps, cooling caps, or hypothermia caps. These caps have other medical uses including treatment of newborns with encephalopathy.

Ice packs are cumbersome, difficult to apply to the entire scalp, and must be changed frequently as the ice melts.

Cooling caps are something like a helmet filled with frozen material. Caps must be replaced as they warm up.

Scalp cooling systems use a helmet attached by a hose to a cooling machine, allowing for complete scalp coverage and temperature regulation. A second insulating cap is worn over the cooling cap

Clinical trials

Clinical trials have established the effectiveness of scalp hypothermia for preventing hair loss. Effectiveness was confirmed by a recent systematic review. But counterintuitively, another systematic review showed no improvement in quality of life.

A 2017 study of stage 1 and 2 breast cancer patients was multicenter, randomized, and controlled, with 142 participants and with blinded evaluators. It used a scalp cooling system for 30 minutes prior to and during and 90 minutes after each chemotherapy infusion.

It found that half of the treatment group and none of the untreated control group had hair preservation, defined as no hair loss or less than 50% hair loss and no need to wear a wig. Degree of effectiveness varied by chemotherapy drug and by study site (perhaps due to differences in experience fitting the caps or to demographic differences?). Treatment did not improve psychological or social functioning. Six subjects withdrew because of discomfort, anxiety, or claustrophobia. Most subjects found the device reasonably comfortable. Side effects were generally mild; they included chills, dizziness, headache, nausea, paresthesia, pruritus, sinus pain, skin and subcutaneous tissue disorders, skin ulceration, scalp pain, and dry skin.


Not everyone is eligible. Cold caps are not appropriate for patients with lymphoma or leukemia. There is a long list of contraindications. Thick hair may impede success. There are numerous scalp cooling systems on the market such as Dignicap and Paxman; there are no comparison studies. Some cold caps are FDA approved; others aren’t (Penguin, Arctic, and others). The cost may be as high as $3,000. Putting the device on involves a cumbersome wrapping and fitting procedure. Most insurance doesn’t cover these treatments. Paxman warns that the first 15-20 minutes can be very uncomfortable until the patient acclimates to the cold; they suggest that pain medication might help. The system must be used for 30 minutes before the chemotherapy infusion, throughout the infusion (however long that takes, sometimes a matter of hours) and for 90 minutes after the infusion. When treatment decreases hair loss, the reduced hair loss does not appear to improve the patient’s psychological or social functioning or quality of life, so patients may wonder why they should go to all that bother for no real benefit. Is having more hair worth it if it doesn’t make you feel any better?

Conclusion: Effective, but not for everyone

There is good scientific evidence that scalp cooling systems for appropriately selected chemotherapy patients will reduce their hair loss. Some patients will embrace these treatments as worthwhile, but others may balk at the expense, the long time the cap must be worn, the discomfort, and the cumbersomeness of the systems. Patients should be fully educated about the pros and cons so they can make an informed decision.


Posted by Harriet Hall

Harriet Hall, MD also known as The SkepDoc, is a retired family physician who writes about pseudoscience and questionable medical practices. She received her BA and MD from the University of Washington, did her internship in the Air Force (the second female ever to do so),  and was the first female graduate of the Air Force family practice residency at Eglin Air Force Base. During a long career as an Air Force physician, she held various positions from flight surgeon to DBMS (Director of Base Medical Services) and did everything from delivering babies to taking the controls of a B-52. She retired with the rank of Colonel.  In 2008 she published her memoirs, Women Aren't Supposed to Fly.