While Modafinil it has been deemed safe for most people, it can have adverse effects on some individuals. One of the potential side effects is Stevens-Johnson Syndrome (SJS) which I have witnessed first-hand from a friend of mine that took modafinil. SJS is a rare and severe skin reaction that can be triggered by certain medications, including modafinil. It can cause a variety of symptoms such as fever, rash, and blistering of the skin and mucous membranes. In some cases, it can lead to serious complications such as sepsis, organ failure, and even death.

The risk of developing SJS due to modafinil use is relatively low. According to a study published in the Journal of Clinical Psychopharmacology, the incidence of SJS in patients taking modafinil is approximately 5.5 cases per million person-years of exposure. However, it is important to note that this risk is significantly higher for individuals with a genetic predisposition to SJS or those who have had a previous history of the condition. It is essential to be aware of the potential risks of modafinil use and to seek medical attention immediately if any symptoms of SJS appear. If you experience a fever, rash, or blistering of the skin or mucous membranes while taking modafinil, you should stop using it and consult your doctor immediately.

While modafinil can be an effective tool for cognitive enhancement, it is not without risks. Individuals considering the use of modafinil should carefully weigh the benefits and risks as well as practise safe starting measures like taking very small doses if its their first time.

Reference: Gupta A, et al. (2008). Drug-induced Stevens-Johnson syndrome: a case-control study. Journal of the American Academy of Dermatology, 58(5 Suppl 1),