2-Fluoroamphetamine - 2-Fluoroamphetamine (2-FA for short) is the most basic of all the fluoroamps. It produces a stimulation that's very productive & good for things like homework or house work similar to how prescription stimulants work. The biggest downside I consistently got was a worrying headache in the back of my head that felt like a sharp, stabbing pain when I'd take 2-FA. It made me worry just how safe this one was so I tried to limit my use of it as much as possible. But it was a decent standby when I could not obtain the others I preferred.
2-Fluoromethamphetamine - 2-FMA is my favorite of the functional fluoroamphetamines. Compared to 2-FA, it has a much smoother effect & no headache at any dose. The stimulation is extremely enjoyable & makes you want to be active physically. I exercised a ton on 2-FMA & tianeptine, which was a brilliant combo when I was dealing with post-acute etizolam withdrawal. Of course a drug that contains the word "methamphetamine" in the name is going to cause some trepidation, and rightfully so. But I've tried actual meth once & they're not that similar. 2-FMA is oddly more stimulating than Adderall or Dexedrine for me, which have more of a sleepy effect at the low doses I've tried. 2-FMA will make you get up & moving instead of staying stuck in your head on a mental task but is not jittery like caffeine. Best of all worlds.
4-Fluoroamphetamine - 4-FA was the first fluoroamphetamine I tried & by far the most fun. This one is like a love child of Adderall & MDMA--a speedy roll that lasts hours & has less of a comedown than actual Ecstasy. You feel incredibly social & outgoing without the whole cuddle puddle/sensory overload aspect. But lord help you if you try to snort it. The pain is like a mixture of battery acid with ghost pepper sauce sprinkled on top. When I was in the depths of etizolam abuse I snorted a lot of 4-FA & my nose was in terrible shape. My late 20s were awash in this pink sparkly powder & I don't regret it for the most part.
I eventually "lost the magic" presumably by damaging my serotonin receptors, so I quit all empathogens & went on Prozac. It was an amazing run while it lasted but I won't miss the sleep paralysis, next-day depression & overheating of my 4-FA days. Another side effect is rapid & extreme weight loss; more than with a straight-up stimulant. 4-FA raises body temperature, making it a thermogenic substance on top of its stimulant effects. I got down to 117 lbs & my bones were showing at the height of my abuse. There's no denying I was irresponsible with my often-daily use of this substance but it sure was a great time.
4-Fluoromethamphetamine - Since 4-FA was so wonderful, everyone assumed 4-FMA would be even better...especially since that was how it worked with the 2-FA/FMA series. But most were sorely disappointed. 4-FMA produced little more than dysphoria & overheating for me & most other users. It never took off to the degree the other 3 did. Just goes to show you can never predict the effects of a substance based on its name alone.