So far almost no one contributing to this thread had actual experience with the substance. So I thought I put in my two cents. This is, by the way, my first post here.
I was made aware of 3-FMC by a trip report at another drug related message board. The Guy over there tested a concoction sold in smart shops under the brand name charge+. 3-FMC was supposed to be the active ingredient in this stuff. He insufflated a few grams of it during the course of a week and was pleased with the effects. Allthough he had to concede that psychological dependance developed quickly.
This prompted me to order the pure substance. I have tasted it about half a dozen times. I ingested between 80mg-130mg per dosage always disolved in water.
The main effects manifest themeselves after about 30-40 minutes and last for 3-4 hours. After that a residual stimulation is perceptible for a few hours. Redosing works very well. Three doses in the range indicated above should carry You through a day.
3-FMC is often described as a clean stimulant. This is almost true. It is clearly a stimulant. It eliminates fatigue and exhaustion, gives energy and creates mental alertness. Interestingly the mind is in a very calm state during this.
But it is not entirely transparent. Especially in the first 2 hours I experienced some mood-lift and a sense of increased confidence. This is a subtle effect compared with other stimulants but it's there.
3-FMC raises my blood pressure, but only moderately so, my heart rate seems to be almost normal. Body temperature is raised somewhat under the influence and You can expect sweaty hands. Overall, those side effects are considerably softer than high doses of caffeine or ephedra -my points of reference concerning this substance.
It's not a party drug, there is no euphoria or rush to it. It is effective as a study/work aid and maybe a social enhancer. Sex drive seems to be diminished.
I noticed a weird aftereffect. Dreams become more vivid, and I remember them more easily after 3-FMC use. I did not notice any addictive properties, but I haven't used it extensively enough. There is no immediate urge to redose though.