Hi so here is an example Nitroglycerin. Nitro is used to dilate blood vessels. It is a base drug in the toolkit of emergency providers, and a lot of medicine cabinets. Normally nitro is administered through either a tablet or spray, placed underneath the tongue. The spray has an increased surface area which means it can enter the bloodstream all at once very fast. so the effects can be seen near instantaneously. Nitro can be ingested, and unless you want to die of massive hypotension you don't dump an entire years worth of pills in one go. Also Nitro tends to just be a very fast acting drug
