Last updated on October 19th, 2018

No matter what type of drug or supplement you’re taking, it’s important to know how that drug or supplement interacts with other things you may be taking.

Melatonin is one of the most popular sleep aids in the world. Though it’s naturally produced in the body, anyone who is going to take it as a supplement should be aware of key melatonin interactions.

Here’s a look at melatonin interactions and the precautions you should take before using it as a supplement.

Melatonin Interactions: Stay Safe When Supplementing 1

The Importance of Knowing the Interactions

Why is it important to know melatonin interactions in the first place? Because ignoring interactions can be dangerous to the user of melatonin, or other drugs and supplements.

Almost all drugs and supplement have unique side effects. For example, melatonin side effects can include headaches and vivid dreams. These side effects may not impact everyone who takes the drug or supplement, but those side effects may emerge without interacting with anything else.

But, when it comes to melatonin drug interactions, there may be more severe and dangerous side effects that emerge when the hormone is mixed with other drugs or substances. It’s like when you mix some medications with alcohol, and the mixture induces severe sleepiness — that is an interaction you want to be aware of.

And, finally,it’s even more important to understand potential interactions when children or toddlers are using melatonin.

Major Interactions

There are no “major” melatonin drug interactions as categorized by This may simply be a result of melatonin being an over-the-counter supplement for a hormone that the body produces naturally. If you’re taking prescription drugs, it’s far more likely that they will come with interactions that you need to be aware of.

That said, moderate – and even minor – melatonin drug interactions are important to note. They can still pose a threat to your health and safety, and they can have lasting effects if they go ignored over time. Melatonin is a wonderful supplement both because of its effectiveness and its lack of major interactions, but you still need to take precautions before using.

Moderate Interactions

So-called “moderate” melatonin interactions include the following 11 generic drugs:

  • Anagrelide
  • Deferasirox
  • Fluvoxamine
  • Grepafloxacin
  • Hydroxyprogesterone
  • Ifosfamide
  • Ifosfamide/Mesna
  • Obeticholic acid
  • Osimertinib
  • Vemurafenib
  • Warfarin

Each of these generic drugs includes its own specific melatonin interactions. For example, if you take anagredlide, which is commonly used to treat thrombocytosis, it can increase blood levels and the natural effects of melatonin when the two are mixed.

If you’re using any of the medications listed above, make sure to visit a site like to learn more about their specific melatonin interactions.

Minor Interactions

There are 103 “minor” melatonin drug interactions. That’s too many to list out in this space, but be sure to check each of your current medications for melatonin interactions before using any melatonin supplements.

When you’re dealing with minor melatonin drug interactions, it can be hard to learn more about the specific side effects or dangers related to mixing melatonin with the other drug. In many cases, minor interactions simply mean that the effects of melatonin are enhanced.

But always lean toward safety. If you are taking a drug that creates a minor melatonin interaction, discuss it with your doctor to learn more about any specific threats to your health and safety. You may find that staying safe is simply a matter of modulating your melatonin dosage.

Other Melatonin Interactions

What about melatonin interactions with more common substances? Here’s a look at how caffeine, alcohol and marijuana interact with melatonin:


Most people use melatonin as a sleep aid. Some use it when traveling internationally and fighting jet lag, while others use it for long-term sleeping challenges.

Caffeine is a stimulant that has the opposite effect of melatonin. From a logical standpoint, mixing melatonin and caffeine is a bad idea because you won’t get the effect that you want — assistance with sleeping.

There’s no indication that caffeine and melatonin make “major” or even “moderate” interactions, so there’s no acute threat to your health or safety. But try to avoid mixing the two simply because caffeine is going to make the melatonin far less effective than it would be otherwise.


Unlike caffeine, alcohol is a depressant rather than a stimulant. For that reason, the melatonin drug interactions experienced when taking it in tandem with alcohol are more severe and more dangerous.

For example, when you choose to mix alcohol and melatonin, you may find that you experience:

  • Severe drowsiness
  • Difficulty breathing
  • Dizziness
  • Increased risk of passing out and/or falling

Naturally, each of these things can pose a significant threat in the wrong situation. For example, if you’re taking melatonin and have just one drink, you may be too drowsy to drive — whereas you would normally be fine to drive a vehicle after just one drink.

Also, if your home includes stairs or other obstacles, mixing alcohol and melatonin could pose an even greater risk of falling and injuring yourself. For these reasons, it’s best to avoid mixing alcohol and melatonin altogether.


The interaction between melatonin and weed is an area that needs more study and research. That said, those who have mixed the two describe two results. First, it’s likely that melatonin will increase the sense of euphoria felt when smoking marijuana and that it will make it easier for the user to fall asleep when needed.

But, the interaction of marijuana and melatonin may also make it far more difficult for the user to wake up the next morning. This is always a risk when someone takes melatonin. If you have a hard time waking up after taking melatonin alone, consider decreasing your dosage. And, certainly, be aware that waking up when mixing melatonin and marijuana is far more difficult than when using melatonin alone.

Again, to err on the side of caution, it’s best to avoid mixing melatonin with marijuana, just as it’s best to avoid mixing it with caffeine or alcohol.

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