In the TPI procedure, a health care professional inserts a small needle into the patient's trigger point. The injection contains a local anesthetic or saline, and may include a corticosteroid. With the injection, the trigger point is made inactive and the pain is alleviated. Usually, a brief course of treatment will result in sustained relief. Injections are given in a doctor's office and usually take just a few minutes. Several sites may be injected in one visit.