A heroic dose is a colloquial term used to describe the administration of a very large quantity of a hallucinogenic substance. When this dose is administered, it leads to a very powerful effect, which some people describe as life-changing. Even though taking a larger dose can lead to a more powerful impact, it can also increase the chances of someone suffering serious complications and side effects, depending on the exact type of hallucinogenic substance they are taking. People who ingest a heroic dose often describe more powerful visual hallucinations, auditory sensations, and changes in perception. Many individuals who take a heroic dose have a sitter present with them who can intervene if they start to experience negative side effects.