These syringes are 3 cc each. This is some of the strongest teeth whitening gel available on the market. Only use this gel after consulting your dentist. Results vary, but most people experience very fast and effective teeth whitening. Some people experience tooth sensitivity and gum irritation. The whitening gel is made for the teeth and should not be in contact with the gums. Be VERY careful not to get this strong gel on your gums. This is NOT for first time teeth whitening people.