AC and dose-dense AC

Say it: A-C

Doxorubicin and cyclophosphamide

AC is a 2 medicine chemotherapy for early stage breast cancer, given every 3 weeks or every 2 weeks (dose dense), and usually followed by paclitaxel.

Also called: AC, dose-dense AC, ddAC, AC-T, AC then paclitaxel, Adriamycin Cytoxan, red devil chemo, AC every 2 weeks

What it is

Doxorubicin and cyclophosphamide damage cancer cell DNA in different ways. The goal is cure: to kill cancer cells that may have spread and lower the chance the cancer comes back. AC is most often given for 4 cycles and then followed by a taxane (paclitaxel or docetaxel), a plan called AC-T.

Often used for

• Early stage breast cancer, before or after surgery
• Breast cancer with higher risk features, such as cancer in the lymph nodes or triple negative breast cancer

Dose-dense AC

The same medicines given every 2 weeks instead of every 3 weeks, with pegfilgrastim after each dose. Giving it closer together works a little better for some higher risk cancers.

AC then paclitaxel (AC-T)

After 4 cycles of AC, paclitaxel is given weekly for 12 weeks or every 2 weeks for 4 doses. This is the most common way AC is used.

AC with pembrolizumab

For some triple negative breast cancers treated before surgery, immunotherapy (pembrolizumab) is added along with carboplatin and paclitaxel, then AC.

Every 3 week AC

The standard schedule, given every 21 days for 4 cycles. A white blood cell shot may or may not be needed.

The medicines in this plan

Doxorubicin (Adriamycin)

An anthracycline chemotherapy (a red medicine, sometimes called the red devil). Given through a vein over a few minutes on day 1.

Cyclophosphamide

An alkylating chemotherapy. Given through a vein over about 30 to 60 minutes on day 1.

Pegfilgrastim

A shot that boosts white blood cells. Given the day after treatment, or by an on body injector placed on day 1. Required for dose-dense AC.

How you get it

AC is given in an outpatient infusion clinic. A treatment day takes about 2 to 3 hours. You usually get 4 cycles, either every 21 days (about 12 weeks) or every 14 days with dose-dense AC (about 8 weeks). Many people get a port. Your schedule may be different.

A typical cycle

Day 1

Blood tests, then nausea medicines, then IV doxorubicin and cyclophosphamide.

Day 2

Pegfilgrastim shot, or the on body injector gives it for you. This is needed for dose-dense AC.

Days 2 to 5

Nausea and tiredness are most common now. Urine may look red for a day or two.

Days 7 to 12

White blood cells are lowest. Watch for fever.

Day 14 or 21

Next cycle starts (day 15 for dose dense, day 22 for every 3 weeks).

Common side effects and what helps

• Hair loss, usually complete and starting about 2 to 3 weeks after the first dose. Ask about scalp cooling if you want to try to protect your hair.
• Nausea and vomiting. Take nausea medicines on schedule, even if you feel okay.
• Feeling very tired, often building with each cycle. Plan rest and light exercise.
• Low white blood cells and a higher risk of infection. Wash hands often.
• Mouth sores. Use a soft toothbrush and a gentle salt and baking soda rinse.
• Red or pink urine for 1 to 2 days. This is the color of doxorubicin.
• Changes in periods, or periods stopping. Talk with your team about birth control and fertility.
• Bone pain from the pegfilgrastim shot. Ask your team whether an antihistamine such as loratadine may help.
• Changes in taste. Try plastic utensils and cold or tart foods.

Call your care team right away if you have

• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
• Vomiting that keeps you from drinking for a day, or signs of dehydration
• Pain or blood when you urinate
• Shortness of breath, chest pain, swelling in your legs, or a racing heartbeat
• Pain, redness, swelling or blistering where the IV went in
• Bleeding or many new bruises
• Mouth sores that keep you from eating or drinking

Good to know

• A heart test (echocardiogram or MUGA scan) is done before starting because doxorubicin can weaken the heart.
• There is a lifetime limit on how much doxorubicin you can get.
• Doxorubicin can badly damage the skin if it leaks out of the vein, so it is often given through a port.
• Drink extra fluids and urinate often for a day or two to protect your bladder from cyclophosphamide.
• Do not get pregnant during treatment. Use birth control that does not contain hormones, and ask about fertility protection before starting.
• There is a small long term risk of other blood cancers after this treatment.

At home

• Take your nausea medicines on schedule for the first 2 to 3 days.
• Drink plenty of fluids, at least 8 cups a day unless your team says otherwise.
• Check your temperature if you feel unwell, and call for a fever.
• Have a plan for hair loss, such as a wig, scarf or cap, before it starts.
• Wash hands often and avoid people who are sick.

Questions to ask

• Will I get AC every 2 weeks or every 3 weeks, and why?
• What comes after AC?
• Will I need a port?
• Can I try scalp cooling?
• How will you check my heart during and after treatment?
• How might this affect my fertility and periods?

Breast cancer

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.