Back to Modafinil

Safety question

Is Modafinil safe?

Moderate risk — meaningful at higher doses or in vulnerable users. Modafinil scores 3/5. Adverse reactions are real and worth knowing — cardiovascular sensitivity, sleep disruption, and tolerance development show up at the upper end of the dose range. Cycling and individual response monitoring matter more than for foundational supplements.

Safety score

3 / 5

Evidence grade

A

Severe reactions on file

1

Pubmed cites

3200

Key facts

typical dose
100–200 mg
dose frequency
1 dose
timing
AM (before 10am)
with food
optional
onset
45 minutes
half-life
14 hours
safety score
3/5
evidence grade
A
class
stimulant
PubMed citations
3200
legal status (US)
Schedule IV controlled
legal status (UK)
Prescription-only
legal status (EU)
Prescription-only
legal status (AU)
Prescription-only
primary mechanism
Inhibits dopamine reuptake via the dopamine transporter (DAT), increasing extracellular dopamine in the prefrontal cortex.

Common side effects

Uncommon side effects

Rare side effects

Severe reaction risks

Modafinil has the following documented severe adverse reactions: Stevens-Johnson Syndrome. These are rare but require immediate medical attention if they occur.

Who should not take Modafinil

What "safe" means here

Our safety scoring reflects (a) published clinical and observational literature on healthy-adult use at standard supplement doses, (b) the spectrum of adverse-event reports in the medical and supplement-pharmacovigilance record, and (c) the regulatory status across major jurisdictions. It does notreflect long-term outcomes in populations that haven’t been studied, and it does not substitute for clinical judgement applied to your individual situation.

A 5/5 score does not mean “no risk” — it means risk has been quantified as low in healthy adults at usual doses. Idiosyncratic and allergic reactions are possible with virtually any compound, including those we rate highest.

Full mechanism, citations, and dose guidance for Modafinil are on the main reference page — see Modafinil. For the dose-by-dose breakdown, see Modafinil dosage. To check stack interactions, use the interaction checker.

This page is informational. It is not medical advice and does not establish a clinician-patient relationship. Individual risk varies with genetics, medications, pre-existing conditions, and dose. Always consult a qualified clinician before starting a new compound. See our full disclaimer and terms.