Acid, or Lysergic acid diethylamide (LSD), is a hallucinogenic drug. This means that when consumed, it causes the user to have unusual experiences such as hearing sounds, seeing illusions, and feeling things that are not actually there. A drug with an extensive history of both medicinal and recreational use, LSD use does not come without risks. An acid trip can last 12 hours or more, and when it goes wrong it can go terribly wrong. This substance is common at raves, parties, and music festivals, so knowing what acid looks like and understanding the risks is imperative, especially for young adults and teenagers.