Your healthcare provider may prescribe abemaciclib (sold under the brand name Verzenio) for certain types of breast cancer. As with all prescription drugs, it’s important to understand the side effects.

The most common side effect of abemaciclib is diarrhea. Hair thinning and alopecia (hair loss) are also considered common side effects. But that doesn’t mean everyone who takes the drug will have these effects.

One MyBCTeam member wrote, “I start Verzenio next week and was wondering about hair loss. I’ve heard the diarrhea can be unbearable.”

Here’s how Verzenio and hair loss are connected, based on clinical studies and MyBCTeam member experiences.

Serious Side Effects

It’s possible to have serious side effects from abemaciclib. For instance, low white blood cell counts can increase your risk of dangerous infections. If diarrhea is severe, it can lead to life-threatening dehydration.

Other serious side effects may include lung inflammation, liver problems, and blood clots. See a healthcare professional if you have shortness of breath, chest pain, or a cough that gets worse while taking abemaciclib.

If you’re pregnant or breastfeeding, it’s important to take extra precautions around abemaciclib. You should avoid abemaciclib during pregnancy because it can cause harm to the fetus. Doctors also advise not breastfeeding when taking abemaciclib and for three weeks after the last dose.

Some serious side effects may require your healthcare provider to pause, lower, or permanently stop abemaciclib. For example, they usually pause treatment if you need treatment for a blood clot and may restart it after you are stable.

Contributing Factors for Hair Loss

Hair loss or thinning while taking abemaciclib may not result from the drug itself. Other factors can affect your hair, such as:

• Side effects of other medicines
• Malnutrition from appetite changes during cancer treatment
• Aging

“I began Verzenio in October along with fulvestrant (Faslodex),” shared a member of MyBCTeam. “I started noticing hair loss (on my head and in my eyebrows, eyelashes, and body hair) in March. The thinning is now pretty significant.”

Hair loss and thinning are possible side effects of fulvestrant and other breast cancer medications. Talk to your healthcare team to see if any of your other treatments could be affecting your hair.

If you’re not eating well because of a decreased appetite, your hair may become thin. Sudden weight loss, certain vitamin deficiencies, and insufficient protein can affect hair growth. Meeting with a registered dietitian or nutritionist can help ensure that you’re getting the nutrition your body needs while taking abemaciclib, especially if you have a loss of appetite.

How MyBCTeam Members Cope With Hair Loss During Treatment

No one should underestimate the emotional impact of losing your hair, whether you’re being treated with chemotherapy or a targeted therapy like abemaciclib.

“I wasn’t sure how I would feel about the loss of my hair,” shared a MyBCTeam member. “For me, it is a loss of control. As long as I have hair, the only people who know about my cancer are the ones I tell. Once my hair is gone, everyone will know.”

Sometimes hair loss affects those around us more than we would expect.

Another member shared, “I’m going to get my hair cut today, much shorter because I’m anticipating hair loss. … My daughter is totally against me cutting my hair. She keeps saying that not everyone loses their hair. … From what I see, I will either lose all my hair or it will thin out to practically nothing. I figure going short now will help me cope with the changes.”

For eyebrows, one member shared, “I had microblading before [treatment] started and would recommend getting it done.” Another explained, “Microblading is where they go in with a tiny blade and tattoo your eyebrows. I had mine done a year and a half after I finished [treatment] because my eyebrows never fully came back. … I asked my oncologist if it was safe for me, and he gave me the OK!”

Note that you should ask your oncology team before trying microblading because it can cause allergic reactions and other complications.

Make a Plan That Supports Your Comfort and Confidence

The decision to cut your hair short, get cosmetic treatments, wait and see what happens, or wear wigs and hats is completely up to you. Breast cancer treatment is a challenging journey, so you should do whatever helps you feel comfortable and confident.

Finding a supportive hairstylist and a network of people who have undergone breast cancer treatment will help you navigate any hair changes during treatment. Don’t use any supplements or other over-the-counter treatments for hair growth without first asking your healthcare team for medical advice. A mental health professional can also be a valuable asset to your oncology team if you struggle with depression around these changes.