Nocist Prevent NoCist Prevent is a dietary supplement in vegetable capsules, based on extracts of Cranberry (equivalent to 45 mg of PACs titrated using the BL-DMAC method) and Birch, which promotes urinary tract function and fluid drainage. It contains N-Acetylcysteine. Instructions for use: It is recommended to take 2 capsules daily with a large glass of water, preferably at night before going to bed.