Fentanyl patches contain enough medication for three days. Even the smallest-strength patch contains enough fentanyl (the 12 microgram-per-hour patch contains 1.28 mg of fentanyl) to kill a petite non-opioid tolerant person such as the victim. The higher-strength patches would contain enough to kill several people, as the patches range in dosage of 12 mcg/hr, 25 mcg/hr, 50 mcg/hr, 75 mcg/hr, and 100 mcg/hr. The most commonly prescribed dose is the 25 mcg/hr patch, which contains a total of 2,550 mcg (or 2.55 mg) of fentanyl. The median lethal dose (meaning a dose that would kill 50% of people given it) of fentanyl for non-opioid tolerant adults is 1 mg or 1,000 mcg; the maximum fatal dosage is 2 mg or 2,000 mcg. However, the lethal dose of a drug can vary widely from person to person: it mainly depends on age and weight. A dose of fentanyl that would be lethal to a 30-year-old 300-pound man could potentially kill four 60-year old 100-pound women.