A cold cap is a wearable cooling device placed on the head during chemotherapy to prevent or reduce hair loss. Chemotherapy drugs attack fast-dividing cells throughout the body, and hair follicles are among the most vulnerable targets. By cooling the scalp to near-freezing temperatures, cold caps narrow blood vessels in the scalp, slow down follicle activity, and reduce how much of the drug reaches hair roots. The result: many patients keep a significant portion of their hair through treatment.
How Scalp Cooling Prevents Hair Loss
Chemotherapy-induced hair loss happens because the drugs circulating in your bloodstream reach the hair follicles at their most active growth phase. Cold caps work through three overlapping effects. First, the cold constricts blood vessels in the scalp, reducing the volume of drug-carrying blood that reaches follicles. Second, it slows the metabolic rate inside each follicle, making cells less active and therefore less susceptible to the drug’s damage. Third, the reduced temperature decreases the amount of chemotherapy drug that follicles actually absorb. Together, these effects lower your follicles’ exposure to the drug right when blood concentrations are at their peak.
The National Comprehensive Cancer Network now includes scalp cooling as a recommended prevention strategy for chemotherapy-related hair loss in breast cancer patients, reflecting growing clinical confidence in the approach.
How Well Cold Caps Work
Success depends heavily on the chemotherapy drugs being used. Without any scalp cooling, hair loss rates range from 60% to 100% of patients depending on the regimen. A meta-analysis covering several common drug combinations found that patients who used scalp cooling had a 41% lower risk of hair loss compared to those who skipped it.
In clinical studies, success is typically defined as retaining at least 50% of your hair. By that measure, roughly 40% to 50% of patients using cold caps achieve meaningful hair preservation through their full course of treatment. That means cold caps don’t guarantee a full head of hair for everyone, but for about half of users, the difference is significant enough that they don’t need a wig or head covering.
Results tend to vary by drug class. Regimens combining multiple aggressive drugs generally make it harder to retain hair, while single-agent treatments may yield better preservation rates.
Manual Caps vs. Automated Systems
There are two main types of cold cap, and the experience of using them is quite different.
Manual cold caps work like specialized ice packs. You store them in a medical-grade freezer (or on dry ice) and swap them out for a fresh cap roughly every 30 minutes throughout your infusion, since they warm up over time. Brands like Penguin and Chemo Cold Caps fall into this category. You’ll need a caregiver or helper to manage the caps, and you’re responsible for bringing the dry ice and frozen caps to each appointment. Some companies offer in-person assistance for an extra fee.
Automated scalp cooling systems connect a fitted cap to a small refrigeration unit that continuously circulates coolant at a controlled temperature. You put the cap on once, and it stays at the target temperature throughout your session. The two FDA-cleared systems in the United States are DigniCap (cleared in 2015) and Paxman (cleared in 2017). These machines are typically housed at the infusion center, so there’s no need to transport freezers or dry ice.
What a Treatment Session Looks Like
Using a cold cap adds time before and after each chemotherapy infusion. You’ll start cooling your scalp before the drugs begin flowing, typically 30 to 50 minutes before the infusion starts. The cap stays on throughout the entire infusion. After the infusion ends, you continue wearing the cap for a post-cooling period that ranges from 2 to 3 hours depending on your chemotherapy regimen. Some drug combinations require 120 minutes of post-cooling, while others need a full 180 minutes.
For a chemotherapy session that might normally last 1 to 3 hours, cold cap use can easily double your total time in the chair. That’s a significant commitment, repeated across every infusion cycle for the duration of your treatment.
Side Effects and Comfort
The most common complaint is simply that it’s cold. Patients report feelings of intense coldness on the scalp, headaches, dizziness, local scalp pain, neck discomfort, and a sensation of heaviness from the cap itself. Some people experience itchiness or a feeling of claustrophobia. These side effects are generally mild to moderate, and most patients tolerate them well enough to continue using the cap throughout their treatment course.
One concern that comes up frequently is whether cooling the scalp could allow cancer cells to “hide” there, potentially leading to scalp metastases. A review of 14 systematic reviews found that scalp cooling did not increase the risk of cancer spreading to the scalp. This has been a reassuring finding, though it’s one reason your oncology team will discuss your specific cancer type before recommending cold caps.
Who Should Not Use Cold Caps
Cold caps are not appropriate for everyone. They are contraindicated for patients with cold sensitivity disorders, cold agglutinin disease (a condition where cold temperatures trigger destruction of red blood cells), or cryoglobulinemia. Patients with blood cancers like leukemia or lymphoma should not use scalp cooling, because these cancers involve circulating tumor cells that could theoretically be sheltered in the cooled scalp tissue.
Patients with liver dysfunction may also be poor candidates, since impaired liver function can extend the time chemotherapy drugs remain active in the body, potentially reducing the cap’s effectiveness. Scalp cooling is also used with caution in patients receiving curative-intent chemotherapy for cancers that have already spread widely, and in cancers that carry a higher risk of skin metastases, including some lung, kidney, stomach, and colon cancers.
Cost and Insurance Coverage
Cold cap therapy is an out-of-pocket expense for many patients, though the landscape is shifting. For manual caps like Penguin, rental costs run about $449 per month. A four-cycle chemotherapy regimen lasting three months would cost roughly $1,347, while a longer course spanning five months would run about $2,245. On top of that, you’ll need dry ice for each session, which adds approximately $100 per infusion. If you want a trained assistant to manage cap changes during your appointment, that’s an additional $555 for an eight-hour session.
A growing number of insurance companies now cover scalp cooling, and you can use health savings or flexible spending accounts to pay for it. If you’re considering cold caps, it’s worth calling your insurer directly to check coverage. For patients who qualify based on income, the nonprofit HairToStay partners with certain treatment centers to subsidize up to $1,500 in cold cap costs.