@edwardsruth i am currently doing a fluorouracil and calcipotriene combo treatment. The calcipotriene significantly reduces the amount of time you need to use the fluorouracil. Treatments are usually only 4-6 days (application morning and night). The healing time after is about a week. Harvard did a study on this treatment and found it to be more effective than flourouracil alone. It basically teaches your skin’s t-cells (where applied) to continue to fight precancer after the treatment. I do it every 3 years on face/neck/chest. Some people (due to skin cancer risk or previous skin cancer) do it once a year.

Hope this helps!