You Shouldn't Take This If You Take Melatonin

Melatonin is a naturally occurring hormone in your body that helps regulate your wake-sleep cycle, also known as your circadian rhythm. Your melatonin levels increase when it gets dark outside and decrease during the daytime when you're exposed to light. As a result, some people have lower than typical melatonin levels and have trouble sleeping. An over-the-counter melatonin supplement can help with insomnia, delayed sleep phase syndrome, non-24-hour sleep wake disorder, jet lag, and shift work sleep disorder, and can also help when you're adjusting to a different sleep-wake cycle (via WebMD). 

According to the Mayo Clinic, melatonin supplements are generally safe when taken for sleep for short-term use. Still, it recommends that you take it under your doctor's supervision and treat melatonin as a sleeping medication. Some common side effects are headaches, dizziness, nausea, and feeling tired — and of course the last is usually the desired effect. 

Always tell your doctor what medications you're taking, and whether they are prescribed or over-the-counter. For example, get your doctor's approval before you start taking a melatonin supplement and tell them everything you're taking so they can determine whether it's safe for you to take. 

If you're concerned about drug interactions, you can also consult your pharmacist, who can tell you if you should be taking a melatonin supplement. There are some medications you shouldn't be taking with melatonin. 

WebMD recommends avoiding melatonin if you're already taking medications for sleep. Any sedatives taken along with melatonin can cause too much sleepiness. This can cause a significant interaction. Some examples of sedatives are Klonopin, Ambien, Ativan, and Donnatal. 

Some contraceptives can cause interactions because they can already increase your melatonin levels. Taking both can make you have too much melatonin in your system. 

Caffeine can decrease your melatonin. Avoid any caffeinated foods or drinks with melatonin — coffee, tea, soda, and chocolate. 

Luvox (aka fluvoxamine), per MedlinePlus, is an SSRI used to treat obsessive-compulsive disorder and social anxiety disorder. WebMD notes that Luvox and melatonin taken together can increase the side effects of Luvox. 

Since melatonin can slow blood clotting, avoid taking it with an anticoagulant or antiplatelet medication. That includes over-the-counter ibuprofen, aspirin, and naproxen. 

Melatonin can also increase your blood sugar, so avoid taking it with any diabetes medications to lower your blood sugar. Melatonin will decrease the effectiveness of diabetes medications, and can do this with immunosuppressants too. 

Melatonin can decrease the effectiveness of Procardia XL, a medication used to lower your blood pressure. 

Taking verapamil can decrease the effectiveness of melatonin because it affects how your body breaks down the hormone. Drugs.com notes that verapamil is used to treat high blood pressure, heart rhythm disorders, and chest pain. 

Always consult your doctor before taking melatonin.