Grapefruit peels contain the enzyme bromelain. Bromelain is a protein digesting enzyme that helps cleanse the skin by gently removing the older, upper layers of your skin. Rub the inside of the peel against your face as a cleanser. While removing older skin cells, the pH of your skin will also be balanced. This promotes softer, smoother skin that looks younger and fresher. After using grapefruit peel on the skin, its important to wear sunscreen as your skin may be particularly sensitive to the sun.