Castor oil application in the belly button may stimulate estrogen production, regulate menstrual cycles, and improve fertility chances. However, it's essential to clean the area, remove any old piercings or scars, and ensure proper hygiene before use. A small quantity of castor oil should be inserted into the navel, leaving a gap between application and surrounding tissue sensitive areas such as the nipple). Applying castor oil can have benefits but also requires precautions and careful consideration.