What is considered heavy usage? i stop quit smoking six days ago, my height is 6'0 and my weight is 190. how long would it take to clear my system.

Here are soem resour: Here are some resources: http://www.cdc.gov/tobacco/data_statistics/fact_sheets/cessation/quitting/ This is the CDC website http://www.lung.org/stop-smoking/i-want-to-quit/benefits-of-quitting.html This is the American Lung Association website. This answers your question even better. Here are some highlites: As soon as you quit, your body begins to repair the damage caused by smoking. See the health benefits you'll experience as soon as 20 minutes to 15 years after quitting. 20 Minutes After Quitting: Your heart rate drops to a normal level. 12 Hours After Quitting: The carbon monoxide level in your blood drops to normal. 2 Weeks to 3 Months After Quitting: Your risk of having a heart attack begins to drop. Your lung function begins to improve.