Hot pepper seedss, of course, are used because of they contain capsaicinoids. The most notable capsaicinoid is called capsaicin, a crystalline substance found almost entirely in the pithy flesh that holds the seeds in place inside the chili. The seeds and skin contain very little, if any, capsaicin. When eaten, capsaicin is detected by heat receptors in the mouth, and the brain responds as though something hot (in terms of temperature) has been consumed. This increases the heart rate, causes perspiration, and the release of endorphins into the blood stream. The result is that (for those that like chilies) the heat “feels good.”