RENISAN CIST 50 CAPSULE Concentrate for kidneys and cystitis. Renisan, thanks to the extracts of Bearberry, Cranberry, Grapefruit, and Mannose, is the ideal supplement for the treatment of urinary tract infections. Warning: It has been shown that grapefruit can interfere with some types of medications (including birth control pills and cholesterol-lowering drugs), and it may take very little, such as a juice plus a whole fruit, to decrease the absorption of medications with dangerous health risks. Do not use during pregnancy. It is recommended to take three capsules a day.