Ibrance (palbociclib)
Targeted therapy pill (CDK4/6 inhibitor) · Used for: Breast cancer
💊 Taken by mouth · Targeted therapy pill (CDK4/6 inhibitor)
Cliff notes
What it is: Targeted therapy pill (CDK4/6 inhibitor).
How it's given: By mouth once a day for 21 days, then 7 days off (a 28-day cycle), with hormone therapy. Tablets can be taken with or without food; capsules should be taken with food.
How it works: Ibrance blocks proteins called CDK4 and CDK6 that help cancer cells divide. It's used for hormone receptor-positive, HER2-negative advanced breast cancer, together with hormone therapy.
Common side effects and what helps at home
| Side effect | What can help |
|---|---|
| Low white blood cells (neutropenia) | This is very common. Wash your hands often and avoid sick people. |
| Tiredness | Rest and short walks help. |
| Nausea | Small meals; ask about anti-nausea medicine. |
| Mouth sores | Soft toothbrush, salt water rinses. |
| Hair thinning | Usually mild. |
| Diarrhea | Fluids and bland foods. |
| Infections | Infections are listed as very common. Wash hands and report fever. |
Not everyone gets these. Your team may suggest other ways to manage them.
Call your care team now if you have:
- Fever of 100.4°F (38°C) or higher or chills
- New or worse cough, chest pain or trouble breathing (possible lung inflammation)
- Unusual bleeding or bruising
Call 911 for trouble breathing, chest pain or signs of stroke.
🗓 What to expect
1️⃣ Before you start
- Ask your team for a written schedule and an after-hours phone number.
- Blood counts.
- Bring a list of all your medicines and supplements.
2️⃣ Each day on treatment
- Take it exactly as prescribed, at about the same time each day.
- Don't crush or split pills unless your team says it's OK.
- If you miss a dose, follow the label instructions or call your pharmacist.
3️⃣ Between doses
- Watch for the side effects below and use the checklist.
- Keep up with blood tests and visits.
- Call your team for anything in the red box.
📅 Sample 28-day cycle
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- 28
= 💊 pill day. Days 22–28: no pills (rest week). This is an example; follow the schedule your team gives you.
✅ Side-effect checklist
Print this and check off what you notice so you can tell your team.
| Side effect | Noticed? | Notes for my team |
|---|---|---|
| Low white blood cells (neutropenia) | ☐ | |
| Tiredness | ☐ | |
| Nausea | ☐ | |
| Mouth sores | ☐ | |
| Hair thinning | ☐ | |
| Diarrhea | ☐ | |
| Infections | ☐ |
Help paying for Ibrance
Official manufacturer program:
- Pfizer Oncology Together: Copay savings for commercially insured patients, financial help for others and care-navigator support.
Copay cards are usually only for people with commercial (job or marketplace) insurance. If you have Medicare or Medicaid, look at free-drug programs and these independent foundations:
- PAN Foundation: Copays and coinsurance, including for people with Medicare, when a disease fund is open.
- HealthWell Foundation: Grants for copays, deductibles and premiums when a fund is open.
- CancerCare Co-Payment Assistance Foundation: Help with treatment copays for insured people under income limits.
- Good Days: Copay help and some travel costs.
- NeedyMeds: Free database of assistance programs, open to anyone.
📋 Medicare: Pills you take at home are usually covered by Medicare drug coverage (Part D). Part B covers some cancer drugs taken by mouth if the same drug comes in an injectable form. See Medicare and your cancer drugs.
More: Our guide to paying for cancer treatment.
💬 What experts are saying
Breast cancer specialists on OncLive say low white blood cells is the main thing they watch for with drugs like Ibrance. With Verzenio, diarrhea is the main concern: they advise keeping an anti-diarrhea medicine at home, starting it at the first loose stool, and eating blander, lower-fiber meals. They also note it often settles down after the first several weeks.
Source: HR+/HER2- MBC: CDK4/6 Inhibitor Treatment Toxicities (OncLive, November 1, 2021)
❓ Questions to ask your doctor
- What is the goal of this treatment for me?
- How will we know if it's working?
- Which side effects should I call about right away, and what number do I call after hours?
- Which medicines, vitamins or supplements should I avoid?
- Will this affect my ability to work, drive or care for my family?
- What will this cost me, and who can help me with coverage?
Support groups
- Susan G. Komen: Breast care helpline, treatment assistance and education
- Living Beyond Breast Cancer: Helpline, peer support and programs for metastatic breast cancer
- CancerCare: Free counseling, support groups and financial help
- Cancer Support Community: Support groups, a helpline and the MyLifeLine online community
Common questions
Why do I need blood tests on Ibrance?
Ibrance often lowers white blood cells. Your team checks your counts and may change the dose.
Does Ibrance cause hair loss?
Hair thinning can happen and is usually mild.
Why is there a week off?
The 21-days-on, 7-days-off schedule gives your blood counts time to recover.
📄 The official FDA label for Ibrance, including its patient information section, is on DailyMed.
Written by the Cancer Side Effects Guide team from FDA labels and leading cancer centers. Not medical advice. · Last updated: October 15, 2026 · How we write