How many letters does the top answer for “a hallucinogenic compound obtained from a mushroom” have?

The most common answer is psilocin (8 letters).

Crossword clue: a hallucinogenic compound obtained from a mushroom

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

psilocin 8 letters wn-def

a hallucinogenic compound obtained from a mushroom

psilocybin 10 letters wn-def

a hallucinogenic compound obtained from a mushroom