After each use, make sure to wipe the pen's bristles with a dry tissue. Do not use water.
Firmly replace the pen cap until you hear a soft click to avoid hardening of the tip. If the tip hardens, do not rinse with water. Instead, push the button on the bottom of the pen 2-3 times and new serum will soften the bristles.
Rinse the LED mouthpiece with warm water- it is waterproof. Do not submerge the connector end of the cable in water. Keep the device clean and dry until the next use.