As the Boost spray contains green tea extract it does contain a natural form of caffeine, however this is a very small amount, with just 0.5mg per four sprays.
The purpose of the green tea in the spray is not this caffeine element, but that it is a natural preservative as well as being an antioxidant.
A recent study published in The Lancet (June 2016) has also proven that green tea provides a chemical called epigallocatechin gallate, which contributes to improved cognitive function.