Onset of cocaine 's effects depends on mode of use: IV injection and smoking: Immediate onset, peak effect after about 3 to 5 minutes, and duration of about 15 to 20 minutes Intranasal use: Onset after about 3 to 5 minutes, peak effect at 20 to 30 minutes, and duration of about 45 to 90 minutes Oral use: Onset after about 10 minutes, peak effect at about 60 minutes, and duration of about 90 minutes Because cocaine is such a short-acting drug, heavy users may inject it or smoke it repeatedly every 10 to 15 minutes.