(COLORADO SPRINGS) — November is National Healthy Skin Month and Dr. Aimee Duffy shared some tips for taking care of the body’s largest organ.

Duffy said skin accounts for 15% of a person’s body weight, and the average person has about 300 million skin cells that are teeming with microbes; fungi, bacteria, and mites.

Celebrities often share their favorite skin secrets and Duffy said some of the ones that actually work are using a silk pillowcase, getting enough sleep, avoiding caffeine, and drinking water.