Side effects with Verzenio + AI

Most common side effects

  • Diarrhea
  • Low white blood cell count (leukopenia/neutropenia)
  • Infections
  • Nausea
  • Low red blood cell count (anemia)
  • Vomiting
  • Hair loss or thinning (alopecia)
  • Decreased appetite
  • Tiredness
  • Abdominal pain
Most common side effects with Verzenio + AI

Tell your doctor if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of Verzenio. For more information, ask your doctor or pharmacist.

In a study of Verzenio taken with an AI, it was common for women to experience diarrhea, which was sometimes severe. In some cases, diarrhea led to dehydration or infection. Diarrhea was greatest during the first month and then decreased.

  • The median time to first symptoms was 8 days. The median duration for moderate and more significant diarrhea was 11 days and 8 days, respectively. However, some patients experienced this earlier or later in therapy
  • The diarrhea was managed by their doctor with an anti-diarrhea medicine (for example, loperamide, which is sometimes sold under the brand name Imodium®) and/or by reducing the dose*

*19% had to have their dose omitted, and 13% had to have their dose lowered.

Call your doctor for medical advice about side effects. You are encouraged to report side effects of prescription drugs to the FDA. Visit or call 1‑800‑FDA‑1088.

You may also report side effects to Eli Lilly and Company at 1‑800‑545‑5979.

Will my hair fall out with Verzenio?

  • In a study of patients taking Verzenio + an aromatase inhibitor, 27% of patients experienced hair thinning or loss
  • In a clinical trial of patients with HR+, HER2– metastatic breast cancer, 328 patients with no prior systemic therapy for metastatic breast cancer received Verzenio + aromatase inhibitor.

Learn how to address side effects

Purpose and Safety Summary
Important Facts About Verzenio® (ver-ZEN-ee-oh). It is also known as abemaciclib.

Verzenio is a prescription medicine used to treat a type of breast cancer. It is a medicine you can take if:

  • You have a type of breast cancer called HR+/HER2– (hormone receptor positive/human epidermal growth factor receptor 2–negative) and the cancer has spread to other parts of the body (metastasized)
  • Verzenio is given along with an aromatase inhibitor as initial endocrine-based therapy for the treatment of postmenopausal women, along with fulvestrant in women whose disease has progressed after hormonal therapy, or by itself in adults whose disease has progressed after hormone therapy and prior chemotherapy

It is not known if Verzenio is safe and effective in children.


Verzenio may cause serious side effects, including:

Diarrhea is common with Verzenio, may be severe and may cause dehydration or infection. The most common time to develop diarrhea is during the first month of Verzenio treatment. Your doctor may stop your treatment, lower your dose, or tell you to wait to begin your treatment cycle if you have diarrhea.

At the first sign of loose stools, tell your doctor. You may be advised to start taking an antidiarrheal medicine (such as loperamide) and drink more fluids.

Low white blood cell counts (neutropenia) are common with Verzenio and may cause serious infections that can lead to death. Your doctor should check your white blood cell counts before and during treatment. Tell your doctor right away if you have fever or chills.

Verzenio can cause liver problems. Tell your doctor right away if you have any of the following signs or symptoms of liver problems:

  • Feeling very tired
  • Loss of appetite
  • Pain on the upper right side of your stomach area (abdomen)
  • Bleeding or bruising more easily than normal

Verzenio may cause blood clots in your veins or lungs. These may be serious and have led to death. Tell your doctor if you have the following signs and symptoms of a blood clot:

  • Pain or swelling in your arms or legs
  • Fast breathing
  • Shortness of breath
  • Fast heart rate
  • Chest pain

Verzenio can harm your unborn baby. Use effective birth control during treatment and for at least 3 weeks after the last dose of Verzenio and do not breastfeed during treatment with Verzenio and for at least 3 weeks after your last dose. Verzenio may affect the ability of males to father a child.

Common side effects

The most common side effects of Verzenio include:

  • Nausea
  • Abdominal pain
  • Infections
  • Tiredness
  • Low red blood cell counts (anemia)
  • Low white blood cell counts (leukopenia)
  • Decreased appetite
  • Vomiting
  • Headache
  • Low platelet counts (thrombocytopenia)
  • Hair thinning or hair loss (alopecia)

These are not all the possible side effects of Verzenio.

Tell your doctor if you have any side effects. You can report side effects at 1-800-FDA-1088 or

Before using

Before you use Verzenio, tell your doctor:

  • If you have fever, chills, or other signs of infection
  • Have liver or kidney problems
  • About all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Especially tell your doctor if you take a medicine that contains ketoconazole. Avoid grapefruit products while taking Verzenio. Grapefruit may increase the amount of Verzenio in your blood
How to take
  • Use Verzenio exactly as your doctor tells you
  • Take your doses of Verzenio at about the same time every day
  • If you vomit or miss a dose take your next dose at your regular time. Do not take 2 doses of Verzenio at the same time to make up for the missed dose
  • If you take too much Verzenio, call your doctor or go to the nearest hospital emergency room right away
Learn more

For more information, call 1-800-545-5979.

This summary provides basic information about Verzenio but does not include all information known about this medicine. Read the information that comes with your prescription each time your prescription is filled. This information does not take the place of talking with your doctor. Be sure to talk to your doctor or other healthcare provider about Verzenio and how to take it. Your doctor is the best person to help you decide if Verzenio is right for you.

Verzenio® is a registered trademark owned or licensed by Eli Lilly and Company, its subsidiaries or affiliates.