I always thought that the endorphin high is unrelated to the beneficial effect: any strong pain is normally followed by a release of endorphins to compensate. I

I always thought that the endorphin high is unrelated to the beneficial effect: any strong pain is normally followed by a release of endorphins to compensate. It's why pain and pleasure are often difficult to disentangle. A strong dose of capsaicin will induce a painful sensation in the mouth (you'll feel like burning), which is compensated by a release of endorphins.