That effect comes from a component of the pepper called capsaicin. Dr. Howard Minkowitz with Memorial Hermann Hospital Memorial City says his team uses an experimental drug called Adlea to treat pain. It's a highly purified, concentrated dose of capsaicin.
"And initially it causes irritation of the nerves and then kind of deadens them, so to speak, to result in long-lasting pain control."
Capsaicin has been used before as a pain treatment, but usually topically. Minkowitz is using it internally to numb the pain associated with knee and hip replacement surgery.
"At the end of the surgery, just prior to the surgeon closing the operative wound, he would place it into the wound and at the end of five minutes the surgeon would suck the capsaicin out of the wound and just close the joint up in the normal fashion."
The drug, Adlea is in Phase 3 clinical trials, just prior to FDA review. And Dr. Minkowitz says his studies are blinded, so he doesn't know which patients received Adlea and which received a placebo.
Anecdotally at least, patients report lasting pain relief. The effects can last weeks or even months.
Laurie Johnson, KUHF-Houston Public Radio News.