Cupping Therapy is a form of deep tissue massage. Cups may be made out of glass, bamboo, Earthware and silicone. The cups are placed on the skin and then using a device to suck the air out of the cups, pulling the skin away from the body. Generally, the cups are left on for 20-25 minutes. The cupping breaks capillaries, the small blood vessels bear the skin surface, resulting in red marks where the cups were placed. The red-purple spots can last for several days or weeks.