MDA began to appear on the recreational drug scene around 1963 to 1964. It was then inexpensive and readily available as a research chemical from several scientific supply houses. Although now illegal, MDA continues to be bought, sold, and used as a recreational 'love drug', due to its enhancement of empathy.
A recreational dose of MDA is commonly between 100 and 160 mg. The “S” optical isomer of MDA is more potent than the “R” optical isomer as a psychostimulant, possessing greater affinity for the three monoamine transporter proteins (SERT, NET and DAT). Although there is some debate, the duration of the drug is sometimes believed[by whom?] to be 6 to 10 hours; but most individuals report the duration of the drug's effects to be around 5–6 hours, slightly longer than that of MDMA. (In the late 1990s, Alexander Shulgin changed his opinion of the duration to 3–6 hours).
MDA is thought to be similar in pharmacological mechanism of action and phenomenological effects to its more widely used N-methyl analog, MDMA. MDA causes serotonin and dopamine release by acting as a substrate at the SERT and DAT, respectively. The effect on serotonin may explain the similar euphoric and empathogenic effects of the two compounds MDMA and MDA. However, (S)-MDA has a higher efficacy in stimulating the 5-HT2A receptor than (R)-MDMA; thus MDA tends to cause more psychedelic-like effects, such as visual hallucinations. MDMA can also produce psychedelic-like visual effects, though these are generally less pronounced than those of MDA, or require a heavier dose to become apparent.
MDA is said to share the entactogenic effects of MDMA. While it is generally similar to MDMA, users report that MDA has more stimulant and psychedelic qualities and slightly less intense entactogenic effects than MDMA. MDA is also considered less predictable than MDMA, with effects varying greatly from person to person. However, no properly controlled experiments have compared these drugs in humans. MDA was best known for its enhancement of the experiences of dancing and sex.