It is absorbed & circulates to all tissues approximately 30 minutes after ingestion. It is broken down by the liver & excreted by the kidney. It is a mild stimulant.It increases heat production, blood pressure, urine output & stomach acid. Also, it interferes with adenosine which is a molecule that causes heart pain when the heart is in trouble so people who consume a lot of caffeine may not feel their heart attack! Withdrawal symptoms are headaches, drowsiness, fatigue. It can be decaffeinated 3 ways:methylene chloride which can cause cancer, ethyl acetate which is a safe compound found in fruit, and bubbling water & CO2 over or through the product which is also safe.