Does Melatonin Cause Abnormal Dreams?

Summary: There appears to be a link between melatonin and abnormal dreams. However, very little science exists to explain why. Theories suggest it’s because of serotonin or effects on REM sleep. If you’re worried I think melatonin is often dosed too high. Start at a lower dose and plan on using as a very short-term treatment.

Dear Curtis: I’ve heard that when you take melatonin it can cause some weird dreams and nightmares. Do you know why this happens and what the chances are of it happening?

Ironically, I’ve heard the same stories about melatonin and dreams.

Unfortunately, digging up any facts about how often this happens has proven to be pretty difficult.

PubMed and Drug References

I’ve spent a good amount of time on looking for any studies which have used melatonin. Often times, they’ll also monitor side effects and their rates.

Again, lot’s of melatonin studies there to look through but they really didn’t focus – or mention – the occurrence of bad or weird dreams.

I also looked in a couple of drug references that I use everyday and, again, the same issue. There’s not even a mention of this particular side effect. They list other side effects of melatonin – but not this particular one.

Theories About The Melatonin-Dream Link

I’ve mentioned before that melatonin actually goes hand in hand with a hormone called serotonin. Because serotonin levels go up during melatonin therapy some scientists believe this may explain why there are bad/weird dreams.

Some of the most popular antidepressants around are in a class of drugs which focus on increasing serotonin levels (Prozac, Zoloft, Paxil, etc.). If you look at their side effect profile there can be occurrences of ‘abnormal dreams’.

For example, this side effect is reported with Prozac and can occur in 1% to 5% of users depending on the disease state being treated. However, it’s important to note that in those studies abnormal dreams were also reported in the placebo (sugar pill) group. Often times at the same rates as Prozac.

A second theory revolves around melatonin’s effects on your REM sleep cycle. This theory is even a little more out there because we don’t know exactly how the REM cycle effects dreams or how much melatonin effects REM cycles. Also, because there haven’t been any formal studies performed it’s really hard to put a finger on the relationship.

Finally, some doctors and pharmacists believe that people end up using too high of a dose of melatonin to start with (I often see people stabilized on 3-5mg a day).

I personally think this is one of the best explanations.

Lower Dose, Short Term Use Best

While I think melatonin can be helpful and I’m not afraid to recommend it. I do suggest that you try a lower dose (0.5mg to 1mg) and use it for short-term treatment of sleep problems (i.e., jet lag).

This is one of the better melatonin products I’ve seen and it’s gotten some very positive reviews. I also prefer it because it’s liquid (and it’s a good tasting liquid as well) and can be given in smaller dosages versus some of the commercially packaged pills which you’ll have to try and break in small pieces to get lower dosages.

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