What Are The Side Effects When Using Modafinil?

When modafinil was issued in the precise dosages, the following adverse reactions were experienced when judged against the placebo in trials:

Common Ratio

  • Nausea (11% to 3%)
  • Headache (34% to 23%)
  • Less common Ratio
  • Nervousness (7% to 3%)
  • Insomnia (5% to 1%)
  • Anxiety (5% to 1%)
  • Dizziness (5% to 4%)
  • Infrequent Ratio
  • Chest pain (3% to 1%)
  • Hypertension (3% to 1%)
  • Tachycardia (2% to 1%)
  • Vasodilatation (2% to 0%)
  • Dry mouth (4% to 2%)
  • Paresthesia (2% to 0%)
  • Pharyngitis (4% to 2%)
  • Anorexia (4% to 1%)

The FDA insisted Cephalon change their prescription literature for Provigil to read in Bold font that there were a number of severe and possibly fatal situations that were traced to modafinil usage that included the above mentioned TENS, DRESS syndrome and the quite severe Stevens-Johnson Syndrome SJS.

There is some evidence that if an individual is struggling with gastrointestinal grief, some relief can be found by taking modafinil right after eating. There have been reports of aggressive behavior and sore skin conditions, but these are uncommon. After several weeks, most of the Modafinil side effects will diminish as the body becomes more tolerant of the medication with no dose altering required. Headaches and feelings of anxiety seem to be connected to the dosage amounts someone is taking so logically these individuals could feel better with a brief lowering or split dosage. Only one case of ventricular premature beat (VPB) or extrasystole, unusual heart beat or palpitations, has been reported and was only loosely associated with using modafinil.

Women who take oral birth control pills [BCP] – hormone based contraceptives – should know that modafinil can have an adverse effect on the potency of the BCP they are taking and that it could last for up to a month after they stop taking the modafinil.

Toxic amounts of modafinil are different in varying species. The average fatal dosage for rats and mice is lethal dose 50% [LD50] of a tested population, for Modafinil, which is a bit higher than 1250 mg per kilogram. By mouth, dosages for the LD50 standard tested in rats varied from 1000 mg per kg up to 3400 mg per kg. Modafinil taken by injection into veins, the LD50 was 300 mg per kg for canines. In human studies, 1200 mg each day for 1 to 3 weeks or a single dose to as much as 4500 mg showed no apparent grave effects.

Though as you can imagine there were some unpleasant reactions witnessed by researchers. These included unusual levels of excitement or confrontational anxiety, acute insomnia, petulance, belligerence, bewilderment, apprehension, trembling, racing heart, sleep disorder, queasiness, and loose stools. Up to 2004, the FDA had not heard of any lethal overdose situations with just modafinil in contrast to OD’ing on a combination of medications that contains modafinil. So all that said, oral LD50 consumption of modafinil for individual people really is not available precisely. Nevertheless, it does seem to be more elevated than the oral LD50 of caffeine.