This depends somewhat on the brand you’re using. In general, because caffeine gum works more quickly than caffeine pills, you don’t necessarily have to chew it for long to get the full effects. Many brands say you can expect to feel the effects within 15 minutes, at which point you can spit it out. For brands that have a slow-release formula, you may want to chew your caffeine gum longer than that. For instance, as we saw above, Zenergy chewing gum is designed to give you a controlled release of ingredients. The company claims you’ll feel the effects in as little as 10 minutes, but you may want to keep chewing for longer to get the full benefit. Some of this will also depend on the flavor. While some gum quickly loses its flavor, Apollo Energy gum (reviewed above) is designed to keep its flavor for a full hour. As long as you’re still enjoying the flavor, there’s no reason to spit it out. So, while you should chew caffeine gum for at least 10-15 minutes in order to make sure you feel the effects, how long you keep chewing is up to you. It’s also a good idea to read the label to see what the company suggests.