Modafinil is a stimulant that treats sleep disorders like narcolepsy and obstructive sleep apnea. It can help you stay awake during the day, and it can also reduce insomnia when it’s time to sleep at night.

Common side effects of modafinil 200mg include headache, stomach ache and nausea. It may also cause skin reactions such as rash or itching.

Boosts Energy Levels

The medication modafinil is used to treat excessive sleepiness in people with narcolepsy and other sleep disorders, such as periods of stopped breathing during sleep (obstructive sleep apnea). It also helps people stay awake during shift work and is being tested to see whether it can improve cognitive performance in healthy adults.

The drug is also sometimes prescribed as a "smart drug" to boost alertness and increase concentration in people who do not have a sleep disorder. Past studies of sleep-deprived people have shown that modafinil can reduce the effects of sleep deprivation on vigilance and cognitive function.

However, these studies have not examined the underlying biological mechanisms. For example, brain imaging studies have shown that modafinil interacts with the dopamine system. One study of rhesus monkeys using BOLD fMRI showed that modafinil occupies the dopamine transporter (DAT) in living brain, but not the nitric oxide transporter (NET).

Other studies have shown that modafinil increases dopamine levels in the striatum including the nucleus accumbens. These results suggest that the improvement in vigilance and cognitive functioning may be related to increased dopamine availability, although other mechanisms such as decreased DA receptor down-regulation or changes in affinity are possible.

Improves Concentration

Modafinil has been shown to increase performance in a variety of cognitive tests in healthy subjects and patients with several neurological disorders. In one study of medication-free narcolepsy patients (titrated from 100 to 400 mg/day) modafinil treatment significantly improved arithmetic performance and decreased scalp EEG activity (by LORETA) compared to placebo, and these effects were localized in frontal and anterior cingulate cortices.

Another study found that Modalert 200 Australia reduced errors in the Wisconsin Card Sort Test and interference on Stroop tests in a 3-week double-blind trial, with titration to either 400 or 200 mg/day. These improvements were also correlated with reduced th and d power, and these correlations were especially strong in frontal and anterior cingulate regions.

Modafinil’s ability to improve concentration and vigilance has led to its use by some military personnel in situations of sleep deprivation or jetlag, as it provides alertness without the negative aftereffects associated with stimulants like amphetamine. However, it is not a panacea and high-level performance requires sufficient catch-up sleep. The arousal and activity-promoting effects of modafinil appear to be mediated by activation of catecholamine systems, with a and b adrenergic receptors and DA autoreceptors being involved.

Enhances Memory

Modafinil has shown promising results on enhancing learning and memory in some studies. It can enhance working memory, episodic memory and processes requiring cognitive control, especially in the presence of stress. This has been observed in animal models and human brain imaging.

The authors of one fMRI study found that daily administration of modafinil to schizophrenia patients significantly improved performance on the California Verbal Learning Test and Letter-Number Span task compared with placebo. Interestingly, this was associated with increased left BA 46 activity. The sensitivity of the left BA 46 to variation in behavioral performance is mediated by the anterior cingulate cortex and the mediodorsal nucleus of the thalamus.

Another fMRI study of healthy adults who were given modafinil and then exposed to simulated night shift work, reported that the drug reduced errors on WCST and Hayling Sentence Completion tasks, which involve the use of cognitive control (Nathaniel-James and Frith, 2002). This was also associated with an increase in the connectivity between V1 and specific cerebellar regions, including Crus I, Crus II and VIIIa lobules.

Reduces Stress

The alertness-enhancing effects of modafinil make it a promising drug for reducing stress and anxiety in some clinical conditions. For example, modafinil has been successfully evaluated for reducing fatigue and sedation in multiple neurological and medical disorders, including multiple sclerosis, idiopathic Parkinson’s disease, chronic fatigue syndrome, fibromyalgia, myotonic dystrophy, post-anaesthetic sedation, and obstructive sleep apnea, with positive results (see review by Ballon and Feifel, 2006).

In a study of shift-work sleep disorder patients, modafinil increased cognitive performance during sustained wakefulness and significantly reduced nocturnal decline in performance. In addition, the drug increased the number of correct responses on a computerized task, and lowered the synapse density in frontal cortex regions associated with impulsivity and attention deficits.

Modafinil also reduces the negative mood states that accompany some of these conditions. In a study of myotonic dystrophy patients, modafinil increased self-reported scores on the tension and anxiety subscales of the Profile of Mood States questionnaire, and in a study of obstructive sleep apnea patients, rates of anxiety were reduced by the medication (Schwartz et al, 2003). These studies highlight that modafinil may have a role to play as a treatment for cognitive dysfunction and as an adjunct to antidepressants.

Reduces Anxiety

Modafinil has been shown to reduce anxiety in animal models of phobia and PTSD, and to increase exploratory behaviour in rhesus monkeys. In one study of medication-free narcolepsy patients, open-label modafinil treatment (titrated to 100-400 mg/day over 3 weeks) was associated with improved performance on the Pauli test and reduced anxiety ratings compared with placebo. These effects were correlated with decreased activation by LORETA in the dorsolateral prefrontal cortex and anterior cingulate cortex.

Another human study found that a 3-day regimen of modafinil 200 mg improved performance on a version of the Hayling sentence completion task and on the WCST versus placebo. It also led to greater self-reported vigor-activity and less fatigue-inertia on the Profile of Mood States scale.

In addition, fMRI studies have reported that modafinil enhances the efficiency of prefrontal cortical cognitive information processing and dampens reactivity to fearful stimuli in the amygdala. This suggests that at low doses, modafinil has a unique physiologic profile compared with stimulant drugs.

However, results from a placebo-controlled study of modafinil’s effect on cognitive enhancing and mood-improving tasks were mixed. This may be attributed to the relatively low dose of modafinil used in the study, which was far below the therapeutically prescribed dosage.