Not a stimulant. While we’ll go into the science in a little bit, Modafinil is in a completely different class than Adderall or other study drugs. Rather than getting you ‘high’ or ‘wired’, it promotes wakefulness with the associated benefits. There’s no caffeine-crash once it’s worn off and doesn’t give you the jitters.
Not addictive. So far, there’s been no evidence whatsoever that Modafinil can bring on physical addiction. There’s also little evidence to suggest that people become resistant to the active substance, thereby having to take more and more to keep getting the same effect.
Not known to have many side-effects. I’ll deal with this one further down the line, but there’s only one known serious/debilitating side-effect that occurs in 1 of 200,000 people.
An incredible productivity booster. It works. I can’t tell you how many incredibly productive days I’ve had thanks to this stuff. It’s my secret weapon when I want to write, code or study.
How Does It Work?
First off, it should be noted the science is still out on some of the inner workings of Modafinil. We know it works, but we don’t fully know how or why it works. Not to worry though, the brain is such a complicated piece of machinery, researchers still regularly find new effects of common drugs like painkillers and penicillin. Surprisingly, there's a number of major drugs that researchers still don't fully understand why they work. The best example would be general anaesthesia. This shouldn't be a deal-breaker.
In a nutshell, Modafinil temporarily knocks out your sleep-wake cycle. This is also one of the main distinctions between Modafinil and other stimulants. It doesn’t ‘add’ anything. No high. No sudden burst of energy. Rather, it suppresses the feelings of tiredness and lethargy. Essentially, your brain is temporarily unable to send signals saying you should feel unfocused, tired or burnt-out.
The main mechanism of Modafinil is via orexin. Neurons responding to orexin are found in several areas that are responsible for sleep and wakefulness. When these neurons are activated, they increase the local build-up of dopamine. The orexin then scrambles the outgoing signals telling the rest of your body that you ought to feel sleepy, tired or have low energy. So while your brain might be trying to send out signals that you should be tired, they get intercepted. As a result, you don't feel tired at all.
Dopamine, normally associated with the feelings of ‘success’ and ‘reward’, also contributes to being more impulsive and less focused. By preventing the dopamine from being transported, it intercepts the trigger to feel unfocused. This decrease in impulsiveness has also been effective in dealing with addiction and sticking to a single task while on Modafinil. Modafinil further contributes to a feeling of wakefulness and supposedly improves neural plasticity. A downside of this is that the increased focus can lead to lower creativity, according to a couple of studies.
In essence, Modafinil temporarily ‘blunts’ our creativity by making us more focused, yet somewhat less inventive. This might suggest Modafinil is more useful when you have a large but simple workload or a monolithic task you need to power through. Try to stay off it when you need to come up with a great new idea. (Use LSD or something) [S]
TL;DR: Come up with your billion-dollar idea first, then execute on Modafinil.
While the exact mechanisms of action for Modafinil aren’t fully understood, we know Modafinil influences histamine, norepinephrine, serotonin, GABA, and glutamate production and processing. While explaining all these in detail would take me another seven pages, the gist of it is that these compounds either suppress sleepiness or promote wakefulness and attention.