First, I completely agree with an opinion that the nomenclature of this substance is 4-FA better than 4-FMP. 4-FMP is aggression of 4-Fluoro-(alpha)-Methyl-Phenthylamine, however it's not systematic chemical nomenclature (it's 1-(4-Fluorophenyl)propan-2-amine), moreover it's difficult to understand what it means unless having high-level knowledge of chemistry and psychopharmacology, and this name sometimes potentially confusing with other substances like 4-FMA. 4-FA, in contrast, many researchers may easily guess that it's aggression of 4-Fluoro-Amphetamine, it's clear. I think 4-FMP is named by some vendors because of the name 4-FA has a risk to be mistaken illegal Amphetamines so to prevent these problems they used 4-FMP. It's scientific discussion so I will use 4-FA.
There's an article about differences in vivo pharmacokinetics between d-Amphetamine (d-AMP), d-Methamphetamine, 4-FA, and 4-FMA in Japan (This article is Japanese only so I'll introduce the summarise of this in English). These data are not human's but rats so this may not be adopted to human, so please consider as only scientific data, but it's so precious data.
According to this article the half life of d-AMP (1 mg / kg, and so forth) in rats is approx. 100 min., in contrast 4-FA is approx. 205 min., about 2-fold longer. Interestingly, comparing d-MAP with 4-FMA it's opposite, d-MAP is approx. 110 min., 4-FMA is approx. 60 min.
There are many differences between human and rat in metabolise pathway so it should not too simplify to interpret of course, but if these differences could be neglected, medical research shows that the half life of d-AMP (as prescription medicine Dexedrine in the US) is about 9 hours in children and 11 hours in adults, then 4-FA has potentially over 23-24 hours half-life so it could be ideal medicine for AD/HD because it's no need to take divided and not too long to cause insomnia when comply to the prescription issued by specialist.
And this article also hypothesised the reason why 4-FMA has shorter half life than d-MAP, it says demethylation of 4-FMA is rapidly processing than d-MAP. I cannot any skeptical point in this hypothesis in my knowledge, so please point out if exist something skeptical point in it.
It may support that many researcher said that 4-FA is better than 4-FMA, because many people think that Methamphetamine is stronger than Amphetamine and indeed that's right, but it's not the nature of substances but the fact is only MAP is far more lipophilic than AMP due to -CH3 so easily penetrate BBB then has higher activity than AMP. In fact AMP is slightly stronger than MAP in vitro.
It's shown that Fluorine increase lipophilicity then it's no wonder 4-FA has stronger biological activity than 4-FMA.
Subjectively 4-FA is not so worth to recreational use however it has potentially more effective because due to has less adrenargic property than d-AMP or rac-AMP (Adderall or Dexedrine), it must reduce side effects like agitation, cardiovascular side effects and so on, moreover, weak entactogenic effect might have good influence to those who have AD/HD with Autistic Spectrum for 10-20 mg low dose.
I hope that this substance will not be only treated as "Drugs of abuse" but approved as Rx medicine for AD/HD someday.
(4-FA is completely legal in my country unless to sell or give to others, however it may show pseudopositive reacion to simple drug screening test then it has some difficulties for therapeutic use instead of Adderall which is illegal with no exception, even if doctor's prescription possessing here)
