You should not take Modalert 200 Australia if you are allergic to modafinil or armodafinil, have a history of heart problems (e.g., irregular heartbeat, high blood pressure), or suffer from severe liver or kidney issues. It is also not recommended for individuals with a history of mental health disorders, such as psychosis or severe anxiety, as it may worsen these conditions. Pregnant or breastfeeding women should avoid Modalert 200 unless explicitly advised by a doctor, and it should not be combined with certain medications, like hormonal contraceptives or certain antidepressants, due to potential interactions. Always consult your doctor to determine if Modalert 200 is safe for you.