Peppermint Tea or Gum
Both the smell and taste of peppermint are well known for causing a brief burst of energy. The herb wakes you up and makes you feel alert. It also helps you focus and stay stimulated when you are tired, something you desperately need during the 3:00 p.m. slump. Given that you are often more distractible during the 3:00 p.m. slump, peppermint is even more useful because the scent of peppermint has been shown to make you perform better on tasks that require sustained attention.
Both peppermint gum and peppermint tea are cheap, easy ways to get an afternoon peppermint fix. If you go the gum route, be sure to check the ingredient list. If the gum contains aspartame, as most do, make sure not to chew the gum too late in the afternoon or evening. Aspartame is a sugar substitute that will keep you awake, just like sugar; however, aspartame stays in your system noticeably longer than sugar.
When it comes to tea, again, make sure you read the label. Mint and peppermint teas are often mixed with green tea which is caffeinated. Try to drink herbal tea which is naturally caffeine free, or drink decaf tea. Be aware, however, that decaffeinated tea does contain a small amount of caffeine, so do not drink it in the evening.