Flmodafinil vs. Modafinil | What’s the Best Nootropic For You?

Tomas Thorne

Last Updated: February 2, 2023

Flmodafinil vs Modafinil

Flmodafinil vs. Modafinil

What’s the deal? Is one of these nootropics better than the other? How are they similar, and/or different?

And most importantly, which one might be the best nootropic for you as a researcher or research subject?

Inside this detailed guide, we’ll breakdown what you must know about these two products — while providing in-depth comparisons and explaining the differences noted in research.

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Disclaimer: The contents of Modafinil.com are for informational and educational purposes only. We do not provide legal advice. Likewise, we do not provide medical advice, diagnosis, or treatment. Please consult your physician prior to consuming Modafinil or related nootropics. Your access to Modafinil.com is subject to our full Disclaimer and Terms of Use.

What Is Flmodafinil?

Flmodafinil is a relatively new nootropic. Structurally, it’s identical to Modafinil — with the addition of two fluoride atoms — hence the name Flmodafinil. It’s also known as bisfluoromodafinil, lauflumide or CRL-40,940 [1].

It was discovered in 2013, and has been undergoing clinical trials since 2015 for its potential as a prescription treatment for narcolepsy and other sleep disorders.

However, unlike Modafinil, it’s not currently classified as a prescription drug, so researchers can readily purchase it online. Note that this could change at any time though!

Benefits of Flmodafinil

Flmodafinil works similarly to Modafinil, but its creators boast that Flmodafinil is up to four times stronger. Flmodafinil may also have a longer half-life, meaning that the research drug would stay in your system longer than Modafinil [1].

According to research subjects, some of the benefits of Flmodafinil as a nootropic include:

  • Better focus and concentration
  • Improved mood
  • Increased productivity

However, because it’s still in early testing, we don’t have access to any research that’s been done specifically on the effects of Flmodafinil as a nootropic agent. What we know about Flmodafinil is based on two things: its similarity in structure to Modafinil, and anecdotal reports from research subjects who have been administered Flmodafinil.

Flmodafinil Side Effects

Flmodafinil’s side effects may be similar to those of Modafinil, although the creators of Flmodafinil affirm that its side effects are much milder due to its structural differences. We don’t yet have solid research regarding the potential side effects of Flmodafinil due to the reasons listed above.

However, many Flmodafinil subjects report that they do seem to experience fewer side effects with Flmodafinil than with Modafinil.

Some side effects a research subject may encounter following Flmodafinil administration include [2]:

  • Headaches or dizziness
  • Insomnia
  • Gastrointestinal issues, like nausea or diarrhea
  • Appetite loss

However, it appears that Flmodafinil — for most otherwise healthy subjects — is perfectly safe with a low risk of side effects or complications.

Get your hands on a great Flmodafinil now!

What Is Modafinil?

Modafinil is a prescription drug that’s commonly used to treat narcolepsy and sleep disorders. As mentioned above, it’s structurally very similar to Flmodafinil [2].

Modafinil is the smart drug of choice for many nootropics users because it’s generally effective and safe, with reportedly few side effects.

Benefits of Modafinil

Compared to Flmodafinil, Modafinil is more well understood because there’s much more publicly-available research on it. It’s known as a “wakefulness promoting agent,” according to the U.S. National Library of Medicine [2]. We know that Modafinil has a number of proven general benefits, like:

  • Reducing fatigue
  • Boosting memory
  • Increasing one’s mood and motivation
  • Supercharging focus, concentration and alertness
  • Consistent energy

These benefits are why Modafinil is such a sought-after nootropic by many people, nootropics experts included.

For a more in-depth look at the many nootropic benefits of Modafinil, be sure to read our review of Modafinil benefits.

Modafinil Side Effects

Modafinil does carry some risk of mild side effects, although for most healthy people it’s generally safe and the risk is minimal.

Some of the most common side effects reported with Modafinil use are headache and insomnia. The standard prescription dose of Modafinil is 200mg per day, so most people don’t need to take more than this [2]. Additionally, those who use Modafinil for its nootropic benefits typically are not taking it more than 1-3 times weekly.

Modafinil can be habit forming, so users are well-advised to take regular breaks between uses.

We have a much more complete picture of Modafinil’s safety because it is a prescription drug that has been thoroughly tested and researched.

For more information, check out our articles on Modafinil side effects and safety.

Modafinil vs Flmodafinil

Flmodafinil vs. Modafinil | Similarities

So, how do Flmodafinil and Modafinil stack up in a head-on comparison?

Here’s how they’re similar:


As stated above, Flmodafinil and Modafinil are structurally very similar. In fact, Flmodafinil is considered a “bisfluoro analog” of Modafinil. Translated, that means that Flmodafinil is essentially an exact copy of Modafinil with the addition of the two fluoride units.

Because of these similarities, it appears that Flmodafinil and Modafinil behave similarly as well.


Flmodafinil and Modafinil have similar effects as well. In fact, Flmodafinil is currently undergoing clinical trials to see if it’s an effective treatment for narcolepsy and sleep disorders, the label-indicated use for Modafinil.

Based on their structural similarities and what we know about Modafinil so far, we can surmise that the effects of Flmodafinil and Modafinil are quite similar, including:

  • Energy: Modafinil, of course, is used to promote wakefulness in people with sleep disorders. However, it may also help with fatigue in people with multiple sclerosis and cancer. It can also combat some of the cognition deficits associated with sleep deprivation [3, 4, 5, 6, 7].
  • Learning and Memory: In healthy people and people with depression, Modafinil can improve memory and learning skills [8, 9].
  • Mood and Motivation: Animal studies have noted improvements in motivation with Modafinil administration, and Modafinil may also serve as a mood booster for healthy adults [10, 11].
  • Focus: Modafinil can help to improve one’s focus and concentration, regardless of whether the patient is sleep-deprived or if they’ve been getting adequate sleep [12, 13].

With both Modafinil and Flmodafinil, we find it optimal to take the dose early in the morning to reduce our risk of insomnia. We never want to miss a good night’s sleep, after all, and the stimulating effects of these compounds can definitely make that happen if taking them late in the day!


We can’t say with confidence that Flmodafinil is as safe as Modafinil simply because of the lack of research available on it. However, based on firsthand accounts from research subjects, it seems to be very safe and its creators even suggest that it has fewer side effects than Modafinil.

That said, all subjects are well-advised to treat Flmodafinil with caution even though it’s not (yet) considered a prescription drug. We find that the safety materials available on Modafinil are a great starting point for getting familiarized with the potential safety concerns of Flmodafinil.

Any research subjects with concerns or health conditions, or who are currently taking any prescription medications, should avoid Modafinil or Flmodafinil in the absence of a doctor’s recommendation [2].

Subjects are also well-advised to avoid mixing either of these compounds with other stimulants, or with alcohol [2].

This also applies to subjects who are pregnant, breastfeeding or under the age of 18 [2].

Any Differences?

There are also some key differences between Flmodafinil and Modafinil that researchers and subjects alike should be aware of.

Here’s a few of those:

Prescription Status

Modafinil is a prescription drug, meaning that in most countries the only way to get Modafinil at a retail pharmacy is through a doctor’s prescription. It should be noted that there are reputable online suppliers for those seeking to use Modafinil purely as a nootropic.

On the other hand, Flmodafinil is not currently classified as a prescription drug. Although it’s undergoing clinical trials at the moment, researchers can easily purchase it online as a reference material.

However, this could change at any time if Flmodafinil is approved for prescription use or if there is a change in the regulations applicable to compounds that are structurally similar to existing prescription drugs.


While Modafinil is undoubtedly a favorite among regular nootropics users, the creators of Flmodafinil boast that the research compound is an incredible two to four times stronger than Modafinil — apparently due to changes in how the drug is metabolized and utilized by the human body, owing to the addition of the two fluoride atoms [1].

Although its patent suggests that Flmodafinil is closer to four times stronger, anecdotal reports from research subjects who have used both Flmodafinil and Modafinil estimate that its true strength is closer to twice that of Modafinil.


Additionally, it appears that Flmodafinil may also have a longer half-life—meaning that the research compound may stay in the system for a longer duration compared to Modafinil.

As more research comes out about Flmodafinil, we will have more definitive information about its half-life.


Due to the combination of potentially higher strength and a potentially longer half-life, the dosage recommendations for Flmodafinil tend to be much lower than those for Modafinil.

For research subjects without any prior nootropic use, the applicable Flmodafinil dose is typically about one-quarter of a standard Modafinil dose. For subjects who are more experienced with using nootropics or who have used Modafinil before, the Flmodafinil dosage is typically closer to half of a normal Modafinil dosage to provide similar effects.

For more information on our dosing guidelines, check out our comprehensive dosing guide for Modafinil.

Body of Research

Flmodafinil is much newer than Modafinil and is still in early phases of clinical trials for Food & Drug Administration (FDA) approval. Therefore, we know much less about Flmodafinil than we do about Modafinil.

While we can theorize that Flmodafinil behaves mostly similarly to Modafinil because of its nearly-identical structure, this is not something that we can claim with full confidence. We will have to wait for more research to come out before we can gain a deeper understanding of exactly how Flmodafinil works.


Prices for Modafinil and Flmodafinil are comparable, but Flmodafinil appears to be slightly more expensive. This makes sense, since Flmodafinil is both newer and reportedly more potent than Modafinil, and must be lab-created by its suppliers rather than purchased.

Based on the current prices at our preferred vendors (details below), one 100mg dose of Flmodafinil costs about $3.00-$4.00, with the powder being the less expensive option compared to the liquid.

On the other hand, a 200mg dose of Modafinil (which is the strength equivalent of a 100mg dose of Flmodafinil) costs about $0.90-$2.30 per serving, depending on order size.

This doesn’t include the cost of any applicable taxes or shipping.

Where To Buy Online?

OK, so now you may be wondering where we buy Flmodafinil online and where we buy Modafinil online.

Luckily, that’s pretty easy these days.

For more info about purchasing Modafinil, check out our comprehensive guide to buying Modafinil online.

Alternatively, the vendor recommended below is our current top recommendation:

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For Flmodafinil, we recommend that researchers purchase it through a vendor called science.bio.

They offer Flmodafinil in liquid or powder form, both of which are easy to dose precisely and accurately. Science.bio also has a thorough vetting and quality control process — including third party, independent lab testing — for all of their ingredients and products.

In other words, this vendor’s customers can rest assured that the product they receive is high in quality and exactly what they paid for.

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Modafinil vs. Flmodafinil | Verdict

As we can see, Modafinil and Flmodafinil are very similar, but there are some differences that may make one a better compound than the other.

While Flmodafinil appears to be stronger and has a longer clearance time than Modafinil, the research material is also newer, more expensive, and we know much less about it.

On the other hand, Modafinil has a good reputation as a safe and effective nootropic.

Luckily, both compounds appear to be low-risk with minor side effects for the majority of healthy people.

And by all accounts to date, both pack a serious brain-enhancing punch.


  1. Konofal E, inventor; Nls Pharma AG, Nls-1 Pharma AG, Assistance Publique Hopitaux de Paris APHP, assignee. Lauflumide and the enantiomers thereof, method for preparing same and therapeutic uses thereof. No. US20130295196A1. November 07, 2013.
  2. U.S. National Library of Medicine. Modafinil. MedlinePlus website. February 15, 2016. https://medlineplus.gov/druginfo/meds/a602016.html
  3. Holst SC, Werth E, Landolt HP. Pharmakotherapie von Schlaf-Wach-Störungen [Pharmacotherapy of Sleep-Wake Disorders]. Praxis (Bern 1994). 2019;108(2):131-138. doi:10.1024/1661-8157/a003189
  4. Pigeau R, Naitoh P, Buguet A, et al. Modafinil, d-amphetamine and placebo during 64 hours of sustained mental work. I. Effects on mood, fatigue, cognitive performance and body temperature. J Sleep Res. 1995;4(4):212-228. doi:10.1111/j.1365-2869.1995.tb00172.x
  5. Estrada A, Kelley AM, Webb CM, Athy JR, Crowley JS. Modafinil as a replacement for dextroamphetamine for sustaining alertness in military helicopter pilots. Aviat Space Environ Med. 2012;83(6):556-564. doi:10.3357/asem.3129.2012
  6. Jean-Pierre P, Morrow GR, Roscoe JA, et al. A phase 3 randomized, placebo-controlled, double-blind, clinical trial of the effect of modafinil on cancer-related fatigue among 631 patients receiving chemotherapy: a University of Rochester Cancer Center Community Clinical Oncology Program Research base study. Cancer. 2010;116(14):3513-3520. doi:10.1002/cncr.25083
  7. Rammohan KW, Rosenberg JH, Lynn DJ, Blumenfeld AM, Pollak CP, Nagaraja HN. Efficacy and safety of modafinil (Provigil) for the treatment of fatigue in multiple sclerosis: a two centre phase 2 study. J Neurol Neurosurg Psychiatry. 2002;72(2):179-183. doi:10.1136/jnnp.72.2.179
  8. Müller U, Rowe JB, Rittman T, Lewis C, Robbins TW, Sahakian BJ. Effects of modafinil on non-verbal cognition, task enjoyment and creative thinking in healthy volunteers. Neuropharmacology. 2013;64(5):490-495. doi:10.1016/j.neuropharm.2012.07.009
  9. Kaser M, Deakin JB, Michael A, et al. Modafinil Improves Episodic Memory and Working Memory Cognition in Patients With Remitted Depression: A Double-Blind, Randomized, Placebo-Controlled Study. Biol Psychiatry Cogn Neurosci Neuroimaging. 2017;2(2):115-122. doi:10.1016/j.bpsc.2016.11.009
  10. Young JW, Geyer MA. Action of modafinil–increased motivation via the dopamine transporter inhibition and D1 receptors?. Biol Psychiatry. 2010;67(8):784-787. doi:10.1016/j.biopsych.2009.12.015
  11. Taneja I, Haman K, Shelton RC, Robertson D. A randomized, double-blind, crossover trial of modafinil on mood. J Clin Psychopharmacol. 2007;27(1):76-79. doi:10.1097/jcp.0b013e31802eb7ea
  12. Wesensten NJ. Effects of modafinil on cognitive performance and alertness during sleep deprivation. Curr Pharm Des. 2006;12(20):2457-2471. doi:10.2174/138161206777698819
  13. Walsh JK, Randazzo AC, Stone KL, Schweitzer PK. Modafinil improves alertness, vigilance, and executive function during simulated night shifts. Sleep. 2004;27(3):434-439. doi:10.1093/sleep/27.3.434

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