Caffeine is HIGHLY TOXIC in higher quantities. Excess use with as little as a few grams may result in death. The suggested serving size of Caffeine powder is anywhere from 50mg to 200mg per day, adding up to a total of no more than 600mg per day to be taken in three different servings, depending on intended effect. Accurate measurement requires a milligram weight scale. Caffeine being consumed from other sources, such as coffee and sports drinks, should always be taken into account when apportioning out the remaining supplement amounts to avoid chance of accidental overdose. Do not take if you have a history of heart disease, pregnant or nursing, liver issues or insomnia. If diabetic, it is important to consistently monitor blood sugar while consuming this supplement. If on any other drugs, medications, or suffering from any other ailments or illnesses not mentioned here, it is best to consult a medical professional before usage of this supplement.