Caffeine is a stimulant that is in many plants such as those listed below. Cultures all over the world have found and used native plants for their caffeine value, which gives them energy and alertness. A little caffeine can be good as a stimulant. Too much and you can become jittery and nervous. It has value as a broncho-dilator, making it useful as a preventative for an asthma attack.
Here’s a product that combines many of the above ingredients: