Hi & Welcome. I can understand your concern for the safety of 6-MP. 6-MP is effective in treating active inflammatory bowel disease like ulcerative coltis and in maintaining remission, and is generally safe. However, the following side effects need to be monitored. A temporary reduction in white and red blood cell count, which can increase your risk of infection and anemia. There is also a risk for liver problem & side effects like nausea and vomiting. Regarding Nicotine therapy: Nicotine patch may suppress the immune system and decrease inflammation in ulcerative colitis. It may also increase the production of mucous in the part of the colon where ulcerative colitis usually starts and serves as a protective barrier. It also seems to reduce the painful spasms associated with ulcerative colitis. However, because of the safety concerns the FDA has not approved Nicotine gum or patch for the treatment of ulcerative colitis. Traditionally, ulcerative colitis is managed by short term therapy with Prednisone (for acute flare) & Pentasa for the maintenance therapy. 6-MP is added to Pentasa therapy if there is no improvement. Hope this answers your query.