It has at times been a more popular research chemical because it does have a unique and potentially desirable effect profile.
Not enough is known about the drug to be sure about its safety level, particularly with chronic use.
According to different sources, a dosage of 80-140 mg is considered common; a dose of 50-80 mg produces a mild trip.
4-FA usually comes as a white powder, sometimes in tablets, and it’s best taken orally; either as is or encapsulated in a piece of rolling paper or a capsule. It’s also possible to mix it with some water or fruit juice. 4-FA takes effect within 30 minutes to 1 hour. The whole experience usually takes about 6 hours, with a peak around 2-4 hours. Some users report trips of up to 12 hours.
It’s also possible to snort 4-FA, though this will damage the nasal mucosa and might hurt for up to 15 minutes. When snorted, less of the substance is needed and the effect will start within a couple of minutes. The effect will be shorter and more intense compared to taking orally.
As said before, no official research on 4-FA has been conducted with human beings. As with a lot of research chemicals, by taking them you’ll become your own guinea pig.
As 4-FA is closely related to speed (methamphetamine), you can expect the same health risks apply. This means you should never use 4-FA in combination with an MAOI. MAOIs are most commonly found in prescription drugs, like anti-depressants, but also in a range of natural products like Syrian rue (peganum harmala), banisteriopsis caapi, passionflower and yohimbe.
Individuals with heart disease (i.e. arteriosclerosis, hypertension) should also be extremely careful as amphetamines can be taxing on the heart.
Research shows that amphetamines used during pregnancy may decrease the birth weight of the baby as well as increase the likelihood of cardiac abnormalities (heart problems) and possibly other birth defects. Methamphetamine (speed) is believed to be transferred through breast milk, this might hold for 4-FA as well.
To our knowledge, no fatal incidents with 4-FA have occurred so far.
Not much is known about the long-term effects of 4-FA and even less about its interactions with other substances. In general different amphetamines (MDMA, speed) combine together well, though some users reported 4-FA suppresses the euphoric effects of MDMA.
Some people combine 4-FA with methylone (MDMC), another research chemical that’s closely related to MDMA. Both positive and negative experiences have been reported, though presumably, this combination is quite harmful to the brain, as the neurotoxicity of both substances adds up.