What is Modafinil? 

Modafinil is a medication that is prescribed to people with the sleep disorder, narcolepsy. It may be sold under brand names such as Provigil and Modalert amongst others. It is still not fully understood how Modafinil works, however, it is known to act as a dopamine reuptake inhibitor. Armodafinil is the longer-lasting enantiomer of Modafinil, and so all the information below is the same for Armodafinil. 

Side Effects

Although not an exhaustive list, if you take Modafinil you may experience anxiety, appetite disturbance, chest pain, abnormal heart rhythms, constipation, diarrhoea, gastrointestinal discomfort, headaches, nausea, altered mood, dry mouth, palpitations, insomnia, raised blood pressure, passing urine more often, suicidal thoughts. 

Legal status

Modafinil is a prescription-only medication (POM) in the UK. This means that it is not illegal to be in possession of a POM without a prescription, however, it is illegal to sell POM.

Risks 

Modafinil has is rare cases been known to cause a severe and potentially fatal skin reaction called Stevens-Johnson syndrome. Stevens-Johnson syndrome may start with flu-like symptoms such as joint pain, temperatures, sore throat and cough, with the rash appearing later. If you develop any of these symptoms, or any kind of skin rash, or blistering of your lips then stop taking Modafinil immediately and seek urgent medical attention. 

Modafinil has been known to be addictive, and can worsen mental health conditions such as psychosis or bipolar affective disorder. It is worth noting that worsening of mental health has been seen in those both with and without a pre-existing psychiatric diagnosis. 

Additional Considerations

Modafinil is what’s known in pharmacology as an inducer, meaning it can interact with, and reduce the effects of other medication you may be taking. Modafinil will induce the production of more liver enzymes to break down drugs, meaning there is less time for them to work as they are not present in the body for as long. An important example is oral contraceptive pills and contraceptive implants. This is not likely to be a problem if Modafinil is taken as a one off, however, if Modafinil is taken frequently then the efficacy of oral contraceptive pills and contraceptive implants will significantly decrease, and there would be a risk of unplanned pregnancy if barrier contraception was not used. Hormones prescribed for gender-affirming care will also be less efficacious when taken alongside Modafinil. Intrauterine devices (IUDs) are not affected as hormones are delivered topically.

Modafinil lasts a long time as a result of its long half life - if you're going to use Modafinil try to take it early in the day to minimise insomnia.