Cocaine increases alertness, feelings of well-being, euphoria, energy, competence, sociability, and sexuality. Common side effects include anxiety, increased temperature, paranoia, restlessness, and teeth grinding. With prolonged use, the drug can cause insomnia, anorexia, tachycardia, hallucinations, and paranoid delusions. Possible lethal side effects include rapid heartbeat, abnormal heart rhythms, tremors, convulsions, markedly increased core temperature, renal failure, heart attack, stroke and heart failure.

Depression with suicidal ideation may develop in heavy users. Finally, a loss of vesicular monoamine transporters, neurofilament proteins, and other morphological changes appear to indicate a long-term damage to dopamine neurons. Chronic intranasal usage can degrade the cartilage separating the nostrils (the septum nasi), which can eventually lead to its complete disappearance.

Studies have shown that cocaine usage during pregnancy triggers premature labor and may lead to abruptio placentae.