Dench City Modafinil vs Flmodafinil

These are two substances I have been using as a pre-workout for a few months now and am enjoying them very much, not only as a minor boost in the morning but for what seems to be a better sense of well-being that has been a welcome accompaniment. 

I am however going to delve into what they are and which is more effective.

I can go off on all manner of anecdotal dribble but before I put my experiences into this article let’s get down to some nitty-gritty!

Disclaimer: Obviously this isn’t medical advice and if you have a decent GP or Dr then talk to them about it. Dench City has written this article for educational purposes only, I mean … I shouldn’t have to write this shit but muppets are amongst us. We also aren't doing this for affiliate gain, so no coupon or 10% off, sorry, not sorry. 

Let's start with the more known substance … 

WTF is Modafinil? 

Modafinil is classed as a eugeroic (wakefulness-promoting drug), originally developed in France in 1989 for … surprise surprise, military personnel and administered to officers under the name Virgyl. These poor officers didn’t know what they were taking as this was all before the release of Modafinil as a medication [1].

Many other militaries expressed interest including the US, UK and India where soldiers were sent on long sleep-deprived missions [2]. PEDs in the armed forces, who would have thought 🤨. 

Ok, that’s your short history lesson. Now onto more pressing information. 

Benefits of Modafinil

  • Reducing fatigue
  • Boosting memory
  • Increasing mood 
  • More motivation, concentration and alertness
  • Thought acceleration

It comes as no surprise Modafinil boosts dopamine and targets those receptor sites.



It’s reported that 200mg is sufficient and divided up into two doses taken throughout the day and could be adjusted to 400mg as tolerated [4] (200mg is plenty). Those who take it for nootropic purposes should also take time off and use it only on training days or other related activity days. 


Side Effects?

Some of the most common side effects include insomnia and headaches [4]. 

It’s usually very well tolerated and for most people, it’s generally safe and has minimal risk. 

Be sensible and try a small dose first to see how you react and there is no need to go over 200mg. I know people will be people but treat this substance with respect and you will get the most out of its wonderful effects. 


So WTF is Flmodafinil?

Flmodafinil is a brand-new nootropic supplement developed in 2013. 

It's structurally identical to Modafinil, but with two fluoride atoms added, hence the name Flmodafinil. Bisfluoromodafinil, lauflumide, and CRL-40,940 are some of the other names for it. 

The inventor claims it’s more effective than Modafinil, with fewer side effects. [5].

This means it can be readily available online, but be warned this can change at any time. 

It probably isn’t a surprise to the bodybuilding community, with pre-workouts and other substances that have been banned over the years.



Same as Modafinil but has a longer half-life and is slightly more euphoric. 

Unfortunately due to there not being not many tests, there’s not really much information out there other than maybe the subreddit or self-testing. 



There are some that say between 25mg and 200mg, I've only ever had 50mg in a morning and that has been sufficient, I am a bodybuilder so larger than the usual person. Always to start off low.  


Side Effects? 

Again, much the same, nausea and headaches, not enough information out there at the time of writing.

Although with minimal data, it would seem that Flmodafinil is well tolerated and safe with minimal side effects for most people. 



In my ‘research’ of both, I prefer Flmodafinil, it’s much more stable whereas Modafinil seems to make me all over the place, one minute I'm wired, the next euphoric then the next I'm anxious, then I’m ok. 

Flmodafinil is a lot more stable for me, I don’t feel wired. I do sometimes have tingles which are nice but no anxiety. I do have a better sense of well being and feel these should be seriously considered for the treatment of depressive disorders, but hey I’m just a faceless writer on the net. 

Dan @ Dench City 


[1] - "Les cobayes de la guerre du Golfe". Le December 18, 2005.

[2] - Martin R (November 1, 2003). "It's Wake-Up Time". Wired. ISSN 1059-1028. Retrieved May 23, 2019.

[3] -  Dan Wagener, M.A. - Norepinephrine and Dopamine Reuptake Inhibitors (NDRIs) - - October 26, 2021

[4] - MODAFINIL | Drug | BNF content published by NICE -

[5] - CRL-40,940 - Wikipedia -,940