Caffeine is a very common substance that is contained in chocolate, soft drinks, tea, coffee, and can also be purchased as capsules, tablets, or powder. The chart below shows dosages for common Caffeine products measured in milligrams (mg).

Please Note: Caffeine in concentrated forms such as pills or powders can accidentally be taken in sufficient quantities to cause vomiting, unconsciousness, and death. A single box of Vivarin or No-Doze (US Products) can be fatal if taken at one time. Although possible with coffee or other strongly caffeinated drink, it generally requires much more awareness of the large dosage before dangerous levels are reached.

Oral Caffeine Dosages Threshold 10 - 20 mg Common 50 - 150 mg Strong 150 - 400 mg Heavy 400 + mg LD50 (Lethal Dose*) 192 mg/kg in rats

Onset : 5 - 10 minutes Duration : 1.5 - 5 hours Normal After Effects : up to 24 hours

* LD50 = dose which will kill 50% of the tested animals. It is estimated that fatal doses for humans are between 1 and 4 grams of caffeine, depending on body weight and tolerance.