Javascript is not enabled.

Javascript must be enabled to use this site. Please enable Javascript in your browser and try again.

Skip to content
Content starts here


Leaving Website

You are now leaving and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

5 Types of Drugs That May Curl Your Hair

Prescription medications could be behind sudden changes in hair texture

spinner image woman with curly hair looking in the mirror, she looks concerned
NicolasMcComber / Getty Images

While hair loss is well known as a side effect of chemotherapy, it’s not the only change that some medications can cause to your hair. In a recently published study, California researchers have identified five types of medications that may affect the texture of hair, most often causing it to become curlier.

“Although there are studies summarizing the effects of systemic medications on hair loss and color, medication induced hair texture changes are seldom reported and are poorly characterized in literature,” Celine H. Phong, a graduate student in dermatology at the University of California, Irvine, and colleagues wrote in the study appearing in the .

spinner image Image Alt Attribute

AARP Membership— $12 for your first year when you sign up for Automatic Renewal

Get instant access to members-only products and hundreds of discounts, a free second membership, and a subscription to AARP the Magazine.

Join Now

In fact, the researchers note that most discussions of hair texture changes after medications are on social media, where “patients have coined the term ‘chemo curl’ to describe a common change after chemotherapy.”

To identify which medications may alter your hair, the researchers reviewed results from 31 scientific articles published since 1985 that included data on 2,594 people (average age 48.4 years) who had taken medications associated with a change in hair texture for some of those studied.

Because of the limited data, the researchers admit it is not possible to truly know how prevalent altered hair texture is due to medications, whether it varies depending on ethnicity or how often it is permanent. More research is needed to better understand how often it occurs, to assess its reversibility and to identify changes in patients of different ethnicities, they say.

Why it matters

Although the data is sparse, the incidence of patients (1,049 of 2,594 in the literature reviewed) who experienced altered hair texture after starting on five types of medications is “clearly clinically significant.” The researchers suggest it is important for doctors to be aware of potential changes to hair texture that can accompany certain medications so they can counsel patients about it before prescribing them. Among the studies they reviewed, only a handful of patients were asked how they felt about the hair change — one liked it, five were indifferent and three disliked it, including a man taking an anti-seizure medication who was so shocked by his new curly hair that he cut it off.

“Any medication-induced adverse effect with potential psychosocial impact is important for prescribing physicians to be aware of for discussion with their patients prior to starting treatment,” Phong and colleagues wrote.

Curls, kinks and waves

“The most commonly reported texture changes include new regrowth in a curly, kinky, or wavy pattern. More specifically, curling of hair involves twisting of the hair shaft around a central axis, kinking involves sharper twists or bends, and waving is defined as an increased number of coils and oscillations per unit length,” the researchers wrote. Brittle, dull and other unspecified texture changes were also reported.

The time it took for changes in hair texture to be noticed ranged from three weeks to two years, according to the study. The good news is the phenomenon isn’t always permanent, although researchers found it can take anywhere from three weeks to five years after stopping treatments for the normal texture to return. And change in hair texture was permanent in some of the study patients who took antiretrovirals, retinoids or antineoplastics.

“Only 12 studies across all medication classes mentioned reversibility of the hair changes, and most patients had reversible texture changes after 3 weeks to 5 years post treatment cessation,” the researchers wrote.


AARP® Vision Plans from VSP™

Exclusive vision insurance plans designed for members and their families

See more Insurance offers >

Five classes of medications associated with texture changes

  1. Cancer medications (antineoplastic agents)​ A 2019 study of 1,478 women on chemotherapy for breast cancer found 63 percent saw their hair become more wavy or curly, on average six months after starting the treatment.
  2. Epilepsy drugs (antiepileptics)​ Several case studies have reported patients whose hair became curlier from a few weeks to two years after taking antiepileptic medications.
  3. Acne, wrinkle meds (retinoids)​ Several case studies have reported patients whose hair became curlier from two months to a year after taking retinoid medications that include treatments for eczema and psoriasis.
  4. Immune system regulators (immunomodulators)​ Several case studies have reported a patient experiencing curling hair after three to six months of treatment with an immunomodulator.
  5. HIV treatment (HIV antiretroviral therapy)​ A single case study was found in which a 48-year-old Belgian man’s straight hair curled about 17 months after he began a regimen of HIV antiretroviral medications. His hair remained curly at a follow-up exam more than two years later.

Discover AARP Members Only Access

Join AARP to Continue

Already a Member?

spinner image membership-card-w-shadow-192x134

LIMITED TIME OFFER. Join AARP for just $9 per year when you sign up for a 5-year term. Join now and get a FREE GIFT!