Suitable for use on children aged 4 years and above. Must always be applied by an adult. Can remove in as little as one treatment, but do not treat the same verruca or wart more than 4 times in total. Directions Hold the pen vertically and press the button until the blue gel comes out. Apply one drop of the blue gel to the verruca or wart. Allow the gel treatment to dry for 10-15 minutes.