Generally, a course of treatment of whitening needle is one month, and every 7 days is a treatment cycle, with 4 treatments. Intensive whitening needle is a course of treatment for three months, and every 7 days is a treatment cycle. When injected, the liquid is injected into the human body in the form of drops, and the whitening effect can be gradually seen after 3 days of injection. Generally speaking, the effect of whitening injection can last for 1-2 years.