First up, we have the classic culprits: first-generation antihistamines. These are the OGs of the allergy world, and they’ve been around since your grandma’s heyday. Think diphenhydramine (you might know it as Benadryl®) and chlorpheniramine (often found in cold-and-flu combos).
These guys are masters of making you drowsy. Why? Because they’re not picky. They barge into your brain and block histamine—great for allergies—but they also crash the party in the parts of your brain that control wakefulness. Result? You feel like you’ve been hit by a fluffy, sedative truck.
Taking one of these before work? Bad idea. You’ll be drooling on your keyboard by 10 a.m. Honestly, they’re better suited for bedtime, or for when you’re trying to survive a long-haul flight where you want to sleep through the screaming baby in row 23.
