A Day of Mohs: How to Prepare and What to Expect

Leading Up to Surgery

• Smoking: While not required, if you smoke cigarettes, it is recommended to stop smoking for at least two weeks before surgery, as smoking can slow wound healing. (2)

• Alcohol: Alcohol can thin the blood and increase bleeding, so it is recommended to avoid alcohol for 48 hours before your surgery.(2)

• Medications: Discuss with your Mohs team which medications you are taking and whether any that may need to be temporarily paused. Some Mohs clinics recommend holding certain blood thinning medications before surgery, while others will advise you to continue taking your medications as normal.(1-3) Always follow the guidance of your care team.

The Morning of Surgery

A day of Mohs surgery usually lasts 4-6 hours, though it may take longer depending on how large or complicated the skin cancer is. You will be awake during the procedure because the procedure is done using local anesthetic (lidocaine injections). Most of your time will be spent waiting while the removed tissue is processed and examined under the microscope in the office.(2)

• Pack a book, magazine, or tablet with headphones Bring something to help pass the wait time.(1-2)

• Pack a snack You can expect to be in the Mohs office for at least 4-6 hours. While many clinics offer snacks or have cafeterias, feel free to prepare your own food if desired.(2)

• Eat a normal breakfast or a normal lunch, if your surgery is in the afternoon.(1,2)

• Avoid makeup if the surgery is on your face The surgeon will need to carefully examine your skin to determine the full size and borders of the skin cancer.(2)

• Consider bringing a friend or family member Some patients find to helpful to have someone with them during the day, especially since there can be waiting periods between stages of surgery. If the procedure is around the eye, the wound dressing may temporarily affect your vision and you may need someone to drive you home. Otherwise, many patients can drive themselves.(1-3)

• Wear comfortable clothes You will likely spend much of the day sitting in the waiting room and between the waiting room and procedure room for each stage of skin cancer removal and repair.(1-3)

During Surgery

What is Mohs?

During Mohs surgery, you will be guided to an exam room where the surgeon will numb the area around your skin cancer using lidocaine. Once the area is sufficiently numb, the surgeon will remove the visible tumor along with a thin rim of surrounding tissue. Bleeding will be controlled and a bandage will be placed over the open wound.(3)

You will then return to the waiting room while the tissue is processed and placed onto slides for examination under the microscope. The surgeon will look at the entire edge and underside of the removed tissue to see if any cancer cells remain. If all of the cancer has been removed, you will return to the exam room so the wound can be repaired with stitches, a bandage, or sometimes more complex closures such as a skin graft. If cancer cells are still present, the surgeon will remove additional tissue from the specific area where the cancer remains.(3)

How much pain can I expect?

The lidocaine injection used to numb the area may sting briefly and can cause some mild discomfort. In one study of 259 patients undergoing Mohs surgery, patients reported pain levels of 2-3 out of 10 during numbing injections.(4)

After the area is numb, you should not feel any sharp pain during the procedure. If you do begin to feel pain, let the surgeon know right away. They will immediately pause the procedure and give additional lidocaine to make sure the area is fully numb.

For more detailed information about Mohs, watch our recorded webinar featuring Dr. Stevens, who walks through each step of the process. 

References

1. Mohs Surgery. Mayo Clinic, Mayo Foundation for Medical Education and Research, 19 Sept. 2024, www.mayoclinic.org/tests-procedures/mohs-surgery/about/pac-20385222. Accessed 28 Feb. 2026.

2. Preparing for Mohs Surgery. Stanford Health Care, stanfordhealthcare.org/medical-treatments/m/mohs-micrographic-surgery/preparing-for-surgery.html. Accessed 28 Feb. 2026.

3. Mohs and Dermatologic Surgery Center. Mohs Surgery and Reconstruction: A Handbook for Patients. Dana-Farber Brigham Cancer Center, May 2023. www.brighamandwomens.org/assets/BWH/dermatology/pdfs/Mohs-Handbook.pdf.

4. Dirr, McKenzie A., et al. "Pain of local anesthetic injection of lidocaine during subsequent stages of Mohs micrographic surgery: A multicenter prospective cohort study." Journal of the American Academy of Dermatology 89.1 (2023): 114-118.