LSD is an illegal drug. A tiny amount can change how you see and feel for hours: colours may seem stronger, time may feel wrong, and some people see things that are not there. The trip can feel beautiful, strange, or frightening — you cannot honestly promise which. It is not alcohol, not cannabis, and it is not the club tablet people in Taiwan often call 搖頭丸 (that is a different drug). In English, some people also say acid for this. It is a hard drug in the eyes of the law in Taiwan and in most countries, and a “small” dose is still enough to matter. Though actually, the same three letters in older British writing meant pounds, shillings and pence — everyday money before decimal coins — but that is a different LSD, not the drug.