If you're a regular reader of this website or have looked into nootropics elsewhere, you've probably heard of modafinil. It's one of the most popular and widely used nootropics available today.

But did you know that there are several other nootropics that are very similar to modafinil? That's what this research-backed article is all about: the different afinils.

What Are The Afinils?

These are substances that are all chemically related and have similar effects. They are classified as eugeroics or wakefulness-promoting agents. Eugeroics help you to stay awake and focused even when you are behind on sleep.

The most popular and well-known eugeroic is modafinil, but there are several others. They are all chemically similar and their names all end with the suffix -afinil. Some of them have tons of research to support their safety and effectiveness. Others are relatively new and are in the process of being studied.

Now let's take a look at the different afinils. We'll dive into the research that has been done on each and see what people around the internet are saying about them. The first three have all been extensively researched and shown to be safe and effective while the last three need more human studies before such claims can be conclusively made.

The Different Afinils

1. Modafinil

It only seems right to start with modafinil. It's by far the most popular afinil being used around the world today. Modafinil was first created in 1970's France. In 1998, it was approved by the Food and Drug Administration (FDA) to treat narcolepsy.¹

Since then, it's also been approved by the FDA to treat shift work sleep disorder and sleep apnea.² It's also used off-label to treat a variety of disorders including depression, chronic fatigue syndrome, daytime sleepiness, and several others. And of course, modafinil is popular in the nootropics community for its ability to increase focus, improve attention and memory, and promote wakefulness.

A PubMed search for modafinil brings up over 2,100 results with more than 500 of them being from the last 5 years.³ It has been scientifically studied far more than any of the other afinils. Although the results of these studies have been somewhat mixed, the majority of them show that modafinil improves cognition without many or any side effects.

A systematic review published in 2015 showed that modafinil enhances attention, executive functions, and learning.⁴ This review looked at 24 different studies that had been conducted between the years of 1990 and 2014. In addition to the cognitive improvements listed above, the reviewers state that they “did not observe any preponderances for side effects or mood changes.”

Another review from 2019 looked at 19 studies done on modafinil.⁵ This review concluded that while modafinil does improve cognition, the effect is mild in people who are not sleep deprived.

The results of these reviews are consistent with what people have been saying on the internet for years. While most people who try using modafinil to improve cognitive performance find that it can be effective, some report that it doesn't do much for them. The only way to know if modafinil will work for you is to give it a try. Negative effects are rare and when they do occur are usually mild. The most common negative effects are headache, nausea, and loss of appetite.⁶ But again, they are rare and go away as soon as you stop taking modafinil.

You can learn more about modafinil here: Modafinil – A Powerful and Popular Nootropic.

2. Armodafinil

Next on our list of the different afinils is modafinil's slightly more-potent sister, armodafinil. It was first approved by the FDA in 2007 and is used to treat daytime sleepiness associated with narcolepsy, shift work, and sleep apnea.⁷ Armodafinil is also popular in the nootropics community for its ability to increase focus and wakefulness.

Armodafinil is very similar to modafinil in its effects and safety profile, although there are a few slight differences. The main difference is dosage. Armodafinil is a little more potent than modafinil and requires a slightly lower dosage to get the same effects. 150 milligrams (mg) of armodafinil is considered to be equivalent to 200 mg of modafinil.⁸

Another key difference is the duration of effects. Plasma concentrations of armodafinil remain higher later in the day than modafinil.⁹ This is consistent with what users often report – that armodafinil's effects last longer than modafinil's.

While armodafinil has undergone extensive research to explore its medical potential and safety, its cognition-enhancing properties in healthy individuals is only starting to be looked at by the scientific community. The research that has been done shows it to have a similar safety profile to modafinil as well as similar effects.

This is consistent with what nootropic users have been saying about armodafinil for years – that it's a slightly stronger, slightly longer-lasting version of modafinil. You can learn more about it here: Armodafinil For Cognitive Enhancement.

3. Adrafinil

Like modafinil, this afinil was first created in France in the 1970's where it was used as a prescription drug until 2011.¹⁰ It was discontinued in favor of other eugeroics like modafinil and armodafinil.

Adrafinil is a prodrug of modafinil.¹¹ What this means is that after you take adrafinil, it is converted into modafinil in the body. For this reason, their effects are very similar. There are, however, a few key differences.

For one, adrafinil takes longer to kick in. This is because, as stated above, the body needs time to convert adrafinil into modafinil as it's being metabolized. Second, adrafinil's dosage is higher than modafinil. A dosage of 300 mg of adrafinil is equivalent to about 100-150 mg of modafinil.

Lastly, adrafinil has more potential negative effects than modafinil. When the body converts it, there is a slight strain placed on the liver. Potential negative effects that are seen with adrafinil but not modafinil include elevated liver enzymes and skin irritation.¹² Generally, adrafinil is safe for occasional use. However, most people prefer to use modafinil or one of the other afinils.

One historical benefit of adrafinil was that it used to be carried by a lot of different nootropic vendors while the other afinils were harder to find. But in recent years, a number of reputable online vendors have popped up that sell modafinil, armodafinil, and some of the other, newer afinils discussed below. Now that it's just as easy – if not easier – to find these other afinils, many nootropic users have stopped using adrafinil.

If you're interested, you can learn more about adrafinil here: Adrafinil For Focus.

4. Hydrafinil

There hasn't been much research done on this one, yet. And none of the research that has been done was conducted on humans. However, that hasn't stopped biohackers from experimenting with hydrafinil.

Also known as fluorenol or hydroxyfluorene, hydrafinil was first used in the late 1930's – but not as a cognitive enhancer. It was used as an insecticide.¹³ Only over the past decade or so have people started using hydrafinil as a nootropic.

While there have not been any human studies done on hydrafinil, there have been a few animal studies that are promising. In one such study, hydrafinil was shown to be 39% more effective than modafinil at keeping rats awake over a 4-hour period.¹⁴ These results are promising, but more research – especially human research – needs to be done before hydrafinil's effectiveness and safety can be concluded.

Around the internet, there are numerous reports of people using hydrafinil. It seems to be well-tolerated with few negative effects. The only negative effects that I've seen mentioned are slight headaches and mild tension in the neck. The consensus seems to be that hydrafinil is weaker than modafinil but that it still promotes wakefulness and focus.

If you're new to nootropics or just a casual user, you'll probably want to stick to the more-researched afinils like modafinil and armodafinil. However, if you are a biohacker who likes to experiment with different substances, you might want to give hydrafinil a try. Though its safety has yet to be scientifically studied, I couldn't find any reports of serious negative effects.

5. Flmodafinil

This is another afinil with very little research behind it. However, it does have some research in front of it. Flmodafinil was patented in 2013 by NLS Pharmaceutics¹⁵ and they began phase-one clinical trials on the substance in December of 2015.¹⁶ Unfortunately, as June 2023, the results of those trials still have not been published by NLS Pharmaceuticals (as far as I can tell).

In spite of the lack of research done on this substance, nootropic users have been experimenting with flmodafinil for years. Also known as fluromodafinil, lauflumide, bisfluromodafinil, and CRL-40,940,¹⁷ nootropic users claim that flmodafinil is much more powerful than modafinil. Though there have not been any human studies published, there have been animal studies done that support this claim.

A 2018 study done on rats found that flmodafinil was significantly more powerful than modafinil.¹⁸ With less than half of a typical modafinil dose, the wakefulness that flmodafinil created lasted much longer. Additionally, after the effects of flmodafinil wore off, less sleep was needed by the rats who were given it than by rats that were given modafinil.

These results are consistent with what people around the internet have been saying about flmodafinil for years. Users often report that they experience a serious increase in both focus and wakefulness with a much-lower dose than they'd use for modafinil. The general consensus is that it is very similar to modafinil in its effects, only much stronger.

I couldn't find any reports of serious negative effects from flmodafinil. In fact, many users report that they have fewer undesirable effects from flmodafinil than from modafinil. It certainly seems safe for most people based on anecdotal reports. However, until controlled clinical trials are conducted, flmodafinil's safety cannot be conclusively stated. Like hydrafinil, new nootropic users will probably want to steer clear of this one for a while until more research has been done.

6. Fladrafinil

The last afinil on our list is fladrafinil – not to be confused with #5, flmodafinil. Fladrafinil, aka fluroafinil or CLR-40,941, has had even less research done on it than the previous two afinils. But just like with the last two afinils we looked at, this lack of research hasn't stopped nootropic users from trying it. And many of them have raved about how fladrafinil is superior to all the other afinils mentioned above.

What little research has been done on this interesting substance does seem to support their claims. Fladrafinil was patented in France in 1982 and then in the United States and several other countries in 1983.¹⁹ But since then, very little research has been published. What has been published shows that fladrafinil seems to be significantly more powerful than modafinil. And although it has not been studied in humans, fladrafinil seems to have an anti-aggressive effect in animals while modafinil does not.²⁰

Compared to the more popular afinils like modafinil and armodafinil, fladrafinil seems to be favored by nootropic users who have tried them all. They often state that they experience more wakefulness and focus with a much-lower dose.

Like numbers 4 and 5 on our list, fladrafinil is probably best suited for experienced nootropic connoisseurs. Even though fladrafinil users rave about its powerful effects and no serious negative effects have been reported, this substance has not gone through extensive safety trials like modafinil and armodafinil have.

Conclusion

Most nootropic users know about modafinil. But they're often surprised to find out that there are a number of other afinils out there with similar cognition-boosting effects. The six afinils listed above are currently the most-widely used by biohackers around the world, but there are new ones being investigated all the time. I wouldn't be surprised if modafinil becomes obsolete over the next ten-or-so years and a newer, more-powerful afinil takes its place as the go-to eugeroic.

But for now modafinil remains the king of the afinils. It's been around for a long time, has undergone extensive clinical trials and safety testing, is an approved medication in several countries around the world, and is easy to buy online in most other countries.

If you're new to the wonderful world of nootropics and are thinking about trying one of the afinils on this list, you'll likely want to stick to one of the afinils that have been extensively studied in humans like modafinil or armodafinil. They've both been the subject of plenty of research and have been shown to be quite safe for most people. Adrafinil can also be a good choice, as it has undergone plenty of human safety trials as well. Like with any substance, it's always a good idea to talk to your doctor before taking an afinil, especially if you're currently on any prescription medications. And since the legal status of some afinils vary from country to country, make sure to familiarize yourself with your country's laws regarding them.

If you're interested in trying modafinil or armodafinil and live in a country they can be shipped to, I recommend checking out ModafinilXL. They have excellent products, reasonable prices, lots of great discounts, fast and discreet shipping, and top-notch customer service. You can read our review of them here: ModafinilXL Review.

References

[This post was originally published on January 25, 2020. Updated June 23, 2023.]