Cold Caps & Hair Loss
- Scalp hypothermia — scalp cooling, or cold caps — lowers scalp temperature before, during and after chemo sessions to protect hair follicles.
- Cold makes scalp blood vessels constrict and shrink, sharply reducing blood flow so much less chemo drug reaches and damages follicle cells.
- Research notes thick hair acts as an insulator, so the scalp may not get cold enough for full protection.
- Scalp cooling does not prevent hair loss or thinning from immunotherapy or targeted drug therapy, which don't act on the body like traditional chemo.
- Automated systems like Dignicap, Paxmin and AMA are FDA-cleared and plug into a machine that circulates cooled liquid at a precise temperature.
- Manual gel caps are not FDA-regulated, must be frozen in a freezer or dry ice, and have to be swapped for a fresh cap every 30 minutes.
- It is not for patients with blood-based cancers (leukemia, lymphoma, multiple myeloma), central nervous system cancers, severe liver problems, or anyone under 18.
- Side effects are usually tolerable: headaches, nausea, dry skin, claustrophobia from the tight chin strap and the general discomfort of a freezing head.
- Rare scalp thermal injuries resembling frostbite almost exclusively involve unregulated manual caps packed in dry ice; automated machines have strict temperature controls.
- Starting January 1st, 2026, Medicare will cover FDA-cleared automated scalp cooling — cap fitting, patient education and cooling time — and nonprofits like Hair2Stay and the Rapunzel Project help patients afford and find it today.