Common effects include visual snow and palinopsia. It is possible for LSD to induce either intermittent or chronic visual hallucinations, in spite of no further use. LSD is active in small amounts relative to other psychoactive compounds with doses measured in micrograms. Adverse psychological reactions are possible, such as anxiety, paranoia, and delusions. LSD is pharmacologically considered to be non-addictive with low potential for abuse.

LSD is typically either swallowed or held under the tongue. The liquid serves as a carrier for the LSD, allowing for accurate dosage and administration onto small pieces of blotter paper called tabs. This solid LSD is then dissolved in a liquid solvent, such as ethanol or distilled water, to create a solution. LSD is synthesized as a solid compound, typically in the form of a powder or a crystalline material. LSD is both the prototypical psychedelic and one of the 'classical' psychedelics, being the psychedelic with the greatest scientific and cultural significance. It is used mainly as a recreational drug or for spiritual reasons. LSD is also capable of causing mystical experiences and ego dissolution. Effects typically begin within half an hour and can last for up to 20 hours (although on average, experiences last 8–12 hours). Dilated pupils, increased blood pressure, and increased body temperature are typical. At sufficiently high dosages LSD manifests primarily mental, visual, and auditory hallucinations. Effects typically include intensified thoughts, emotions, and sensory perception. Lysergic acid diethylamide, commonly known as LSD (from German Lysergsäure-diethylamid), and known colloquially as acid, is a potent psychedelic drug.

Blotter acid visions