Here's Why Some People Grow Chemo Curls After Cancer Treatment
Guest Contributor
Hair is more than just a physical feature — it plays a powerful role in how we see ourselves. That’s why hair loss during cancer treatment can feel like an especially difficult part of an already challenging journey. Yet for many patients, the regrowth of hair is a hopeful sign that the body is recovering. One curious phenomenon that often accompanies this regrowth is the appearance of "chemo curls" — when hair that was once straight grows back with a curly or wavy texture. Understanding why this happens reveals not only the resilience of the human body but also the complexity of hair biology.
Chemo curls are a temporary change in hair texture that some people experience after chemotherapy. According to dermatological scientist Desmond Tobin of University College Dublin’s Charles Institute, the vast majority of patients see their hair grow back much the same as it was before treatment. However, in the early stages of recovery, differences in texture and appearance are common. The most frequently reported change is the development of curls in previously straight hair. For most, this altered texture gradually returns to its original state within about a year.
The root of this transformation lies in the way hair is produced. Each strand of hair is formed by a follicle — a tiny, complex structure in the skin that houses stem cells and other cell types. These follicles go through a continuous cycle of growth, rest, and shedding. While we’re born with all the hair follicles we’ll ever have, their activity and the appearance of the hair they produce can shift due to various factors such as genetics, hormones, and nutrition.
Hair texture is largely determined by the shape of the follicle. Round follicles produce straight hair, while more oval or flattened follicles give rise to waves or tight curls. When chemotherapy drugs enter the picture, they target rapidly dividing cells — a hallmark of cancer — but also affect other fast-growing tissues like hair follicles. Tobin explains that because follicles are among the most proliferative tissues in the body, they are particularly susceptible to damage during treatment. This damage can disrupt the normal shape or function of the follicle, resulting in hair that grows back with a different texture or thickness.
The hair loss associated with chemotherapy typically occurs because the treatment forces follicles to expel hairs during the growth phase or pushes them into a dormant state. Once treatment ends, the stem cells within the follicles begin to reactivate, restarting the hair cycle. As this process unfolds, the new hair may emerge altered in shape, length, or even color. Tobin notes that chemotherapy can cause follicles to produce thinner or differently shaped fibers, depending on how each follicle recovers from the drug’s impact.
In addition to texture changes, some patients notice a shift in hair color. This is often due to the temporary effects of chemotherapy on the endocrine system, which regulates hormone production. Hormones influence pigment production, so disruptions can lead to lighter or grayer hair. These changes are usually short-lived, and as the body clears the remnants of chemotherapy drugs, normal hair characteristics often return.
Dermatologist Sunny Wong of the University of Michigan Medical School explains that the drugs used in chemotherapy work by incorporating themselves into replicating DNA. It takes time for the body to eliminate these compounds, and during this recovery window, the signals that regulate the hair cycle gradually re-establish themselves. As the body rebuilds, the hair follicles often recover fully, resuming their usual function and producing hair that resembles its pre-treatment state.
I found this detail striking: although hair typically grows about a centimeter per month, the quality of regrowth can be influenced by overall health. Tobin emphasizes that good nutrition and a healthy blood supply support the recovery of hair follicles. Patients are encouraged to avoid harsh treatments like dyeing or straightening during this sensitive period, as the newly emerging hairs may be more vulnerable to damage.
For those experiencing chemo curls, the change can be surprising, even unsettling. But it also serves as a visible marker of healing. While the altered texture might not last, it reflects the body’s ability to bounce back from intense medical treatment. And though the appearance of hair may shift temporarily, the underlying biology is remarkably robust.
The story of chemo curls is ultimately one of resilience. It highlights how the body adapts to and recovers from trauma, even at the microscopic level of hair follicles. For patients navigating the aftermath of chemotherapy, understanding these changes can offer reassurance — what’s happening on the outside is part of a broader process of renewal within.
