To demonstrate the effectiveness of Sarapin in prolonging the action of neural blockade with improved pain relief. Prospective, continuous, double-blind trial including 500 consecutive patients undergoing either caudal epidural injections; cervical, thoracic, lumbosacral facet joint nerve blocks; and/or intercostal nerve blocks or a combination thereof. Sarapin has been reported as an agent to provide pain relief without motor weakness with an excellent risk/ benefit ratio in neural blockade. Sarapin is a suspension of powdered Sarracenia purpurin (pitcher plant) in alkaline solution. Researchers theorize that the distillate contained an unidentified biological substance that potentiates the action of the ammonium ion. Modest but significant benefits were demonstrated with diagnostic blocks, with diagnostic lumbar medial branch blocks, therapeutic lumbar medial branch blocks, and caudal epidural injections. In an experimental study in the horse, no benefits were seen by injection of Sarapin. The authors proposed that there may not be any benefits in other species as well. Multiple therapeutic agents utilized in neural blockade, including local anesthetics, steroids, and neurolytic agents, have been evaluated extensively. Sarapin has not been evaluated in controlled trials. Five hundred consecutive patients undergoing either caudal epidural injections; cervical, thoracic, or lumbosacral facet joint nerve blocks; or intercostal nerve blocks or a combination thereof were included in the study. Each patient was treated with two blocks. The treatments were dou-ble-blind and prospective. Each patient acted as their own control. The results showed that 500 patients received a total of 828 treatments, once with Sarapin and once without. There were no significant differences between these groups, either with pain relief measured by numeric pain scale or duration of significant relief defined as 50% or greater relief. This prospective, double-blind trial of 500 patients undergoing 828 treatments, one time with Sarapin and a subsequent time without, with each patient acting as their own control, showed no significant differences in the pain relief or duration of significant relief with the addition of Sarapin.