Crystal MDA (3,4-Methylenedioxyamphetamine) is a synthetic psychoactive substance belonging to the amphetamine family. Typically appearing as crystalline powder or crystals, MDA is known for its stimulant, empathogenic, and mild hallucinogenic properties.

Effects may include increased energy, altered sensory perception, emotional openness, and heightened mood. MDA carries risks including increased heart rate, elevated blood pressure, overheating, dehydration, and other adverse physical and psychological effects. Its possession, sale, and use are regulated or prohibited in many countries.