FOLFOX

Say it: FOLL-fox

Leucovorin, fluorouracil and oxaliplatin

FOLFOX is a three medicine chemotherapy plan that is one of the most common treatments for colon and rectal cancer.

Also called: mFOLFOX6, FOLFOX4, modified FOLFOX, FOLFOX6, FOLFOX plus bevacizumab, FOLFOX with cetuximab, FOLFOX with panitumumab, 5-FU, leucovorin and oxaliplatin

What it is

Fluorouracil (often called 5-FU) and oxaliplatin each damage cancer cells in a different way. Leucovorin is a vitamin-like medicine that helps fluorouracil work better. After surgery, the goal is to lower the chance the cancer comes back. When cancer has spread, the goal is to shrink it, slow it down and help you live longer and feel better.

Often used for

• Colon cancer after surgery, to lower the chance it comes back
• Rectal cancer, often along with radiation and surgery
• Colon or rectal cancer that has spread
• Some stomach, esophagus and pancreas cancers

mFOLFOX6 (modified FOLFOX6)

The most common version in the United States. All the IV medicines are given on day 1, then the fluorouracil pump runs for about 46 hours. FOLFOX4 is an older version that spreads the medicines over days 1 and 2.

FOLFOX plus bevacizumab

Used for colon or rectal cancer that has spread. Bevacizumab is added on day 1 to help starve the tumor of blood supply. It can raise blood pressure and slow wound healing, so your team will plan carefully around any surgery.

FOLFOX plus cetuximab

Used for cancer that has spread when tumor testing shows the RAS genes are normal (called RAS wild type, and usually BRAF normal too). It works best for tumors that started on the left side of the colon or in the rectum. It often causes an acne-like rash on the face and chest.

FOLFOX plus panitumumab

Same idea as cetuximab: only for RAS wild type tumors, most often left sided. It also commonly causes an acne-like rash, dry skin and low magnesium.

FOLFOX after surgery (adjuvant)

Given for a set time, usually 12 cycles over about 6 months. For some lower risk stage 3 cancers, a shorter 3 month plan may be an option.

The medicines in this plan

Leucovorin

A form of folic acid that makes fluorouracil work better. Given through a vein over about 2 hours on day 1, at the same time as oxaliplatin.

Fluorouracil (5-FU)

Chemotherapy that blocks cancer cells from copying their DNA. A small amount is often pushed in quickly on day 1, then the rest drips in slowly from a small pump you take home for about 46 hours.

Oxaliplatin

Platinum chemotherapy. Given through a vein over about 2 hours on day 1. It is the medicine that causes cold sensitivity and tingling.

Bevacizumab

Only in the bevacizumab version. An antibody that cuts off the blood supply that tumors need to grow. Given through a vein on day 1.

Cetuximab

Only in the cetuximab version. An antibody that blocks a growth signal (EGFR) on cancer cells. Given through a vein, every 1 or 2 weeks.

Panitumumab

Only in the panitumumab version. An antibody that blocks the same growth signal (EGFR) as cetuximab. Given through a vein on day 1.

How you get it

FOLFOX is given in an outpatient infusion clinic, usually through a port (a small device placed under the skin of the chest). Day 1 in the clinic takes about 3 to 5 hours, then you go home with a small pump that finishes the fluorouracil over about 2 days. Each cycle is 14 days. After surgery, most people get about 12 cycles (6 months); for cancer that has spread, it continues as long as it is helping and you are handling it well, sometimes with oxaliplatin paused after a few months. Your schedule may be different.

A typical cycle

Day 1

Blood tests and a check in with your team. Then anti-nausea medicines, then oxaliplatin and leucovorin through your port over about 2 hours. Any add-on antibody is also given. A quick push of fluorouracil, then the take-home pump is connected.

Days 1 to 3

The pump slowly gives fluorouracil at home for about 46 hours. You may feel tired or queasy and sensitive to cold.

Day 3

The pump is disconnected at the clinic or by a home nurse (some people learn to do it themselves).

Days 4 to 14

Rest and recovery. Blood counts are often lowest around days 7 to 12. Energy usually comes back before the next cycle.

Common side effects and what helps

• Tingling or numbness in fingers, toes or around the mouth, often set off by cold. Wear gloves to reach into the fridge and skip icy drinks for a few days after treatment.
• Tiredness. Short walks and rest breaks both help. Plan lighter days right after treatment.
• Nausea. Take your anti-nausea medicines as prescribed, even before you feel sick.
• Diarrhea. Drink plenty of fluids and use the diarrhea plan your team gave you.
• Mouth sores. Rinse often with a mild salt and baking soda rinse and use a soft toothbrush.
• Low blood counts, which raise the risk of infection. Wash hands often and stay away from people who are sick.
• Sore, red or peeling palms and soles. Use thick lotion and avoid hot water and tight shoes.
• With cetuximab or panitumumab: an acne-like rash on the face, chest and back. Use gentle soap, moisturizer and sunscreen, and ask about rash medicines. Do not use acne products unless your team says so.
• With bevacizumab: higher blood pressure and nosebleeds. Your blood pressure will be checked at each visit.

Call your care team right away if you have

• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
• Diarrhea 4 or more times a day above your normal, or diarrhea that does not stop with your medicines
• Not able to keep fluids down, or feeling dizzy when you stand
• Chest pain, or trouble breathing or swallowing (rarely, oxaliplatin can cause a throat squeeze feeling, or an allergic reaction during the infusion)
• Bleeding that will not stop, black stools or vomiting blood
• Severe belly pain
• A problem with your pump, such as a leak, alarm or wet bandage
• Mouth sores so painful you cannot eat or drink

Good to know

• You will have blood tests before each cycle to make sure your counts are safe.
• Nerve symptoms from oxaliplatin can build up over time. Tell your team about any trouble buttoning, writing or walking, so they can adjust the plan.
• Some people have a gene change (DPD deficiency) that makes fluorouracil much stronger. Ask whether testing is right for you.
• Cetuximab and panitumumab only help when tumor testing shows normal RAS genes, so this testing is done first.
• Bevacizumab is usually paused for several weeks around surgery because it slows wound healing. Your team will time this.
• Cetuximab and panitumumab can lower magnesium, so blood levels are checked.

At home

• Keep the pump in its carry case, keep it dry, and do not shower in a way that wets the tubing. Never pull on the line.
• Avoid cold drinks, cold food and cold air on your face for several days after each treatment. Use room temperature drinks and wear a scarf outside in winter.
• Drink about 8 to 10 cups of fluid a day unless your team told you otherwise.
• Keep diarrhea medicine and anti-nausea medicine at home and know when to take them.
• Use sunscreen and a hat, especially with cetuximab or panitumumab.
• Keep a thermometer at home and check your temperature if you feel unwell.

Questions to ask

• How many cycles will I get, and what is the goal of my treatment?
• Will an antibody (bevacizumab, cetuximab or panitumumab) be added, and why?
• What were my tumor's RAS and BRAF results?
• What should I do if the tingling in my hands and feet gets worse?
• Who disconnects my pump, and who do I call if it alarms at night?
• Should I be tested for DPD deficiency before starting?

Colorectal 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.