Image by Tomascastelazo Capsaicin is the ingredient in hot chili peppers that gives it the heat and burn. It is also known to be effective for a variety of pain relief uses. The capsaicin nasal spray version (see below) available over-the-counter, is thought to work for sinus headaches, migraines , cluster headaches, and even severe nasal congestion by desensitizing the trigeminal nerve (which is accessible through the nose) and reduces CGRP (calcitonin gene-related peptide), thus reducin…