When you reach for melatonin, a hormone your body naturally makes to regulate sleep-wake cycles. Also known as the sleep hormone, it's one of the most popular sleep aids in the U.S.—but it’s not a harmless pill. Many people think because it’s sold over the counter, it’s safe to take anytime, any dose. That’s not true. Melatonin affects your body’s internal clock, and messing with that clock can cause more than just drowsiness.
Common side effects include headaches, dizziness, nausea, and feeling groggy the next day. Some people report vivid dreams or even nightmares. These aren’t rare—they happen often enough that doctors warn against using melatonin for long periods without checking in. It can also lower your blood pressure, which is risky if you’re already on hypertension meds. And if you’re taking blood thinners, antidepressants, or immunosuppressants, melatonin might interfere. One study from the University of Pennsylvania found that people on SSRIs who took melatonin had increased drowsiness and mood swings. It’s not just about sleep—it’s about how it plays with everything else in your system.
Another thing people overlook: melatonin isn’t regulated like prescription drugs. That means the dose on the bottle might not match what’s inside. A 2017 analysis in the Journal of Clinical Sleep Medicine found that 71% of melatonin supplements had more than the labeled amount—some by as much as 478%. That’s not a typo. You could be taking five times more than you think. And if you’re giving it to a kid? Even more caution needed. Pediatricians see cases of accidental overdose from kids mistaking these pills for candy.
It’s not just about what melatonin does to you—it’s about what it doesn’t fix. If you’re struggling with sleep because of stress, anxiety, or a disrupted schedule from screens, melatonin won’t solve that. It just nudges your clock. Blue light from phones suppresses your natural melatonin production, which is why limiting screen time before bed works better than popping a pill. And if you’re taking it to treat insomnia caused by a medication like aripiprazole or metformin, you might need to fix the root cause instead.
There’s no one-size-fits-all dose. Most adults start with 0.5 to 1 mg, taken 30 to 60 minutes before bed. Higher doses don’t mean better sleep—they just mean more side effects. And if you’re still awake after an hour? Don’t take more. You’re not building up a tolerance—you’re just confusing your body’s rhythm even more.
What you’ll find below isn’t just a list of articles. It’s a collection of real, practical insights from people who’ve dealt with melatonin’s side effects, drug interactions, and sleep struggles. You’ll see how it connects to blue light exposure, prescription meds like aripiprazole, and even how supplements like garlic can change how your body handles it. No fluff. No guesses. Just what actually happens when you take it—and what to do next.
