Why exactly is taking melatonin every day bad?

I’ve been using melatonin daily for months, and it seems to help me get regular sleep without any strange side effects, except for some occasional anxiety. Online, I keep seeing that it’s not great to use melatonin every day, but I’m not really sure why.

I usually get a consistent amount of sleep and don’t feel drugged or anything unusual. I’ve also tried other sleep aids, like herbal mixtures, but they leave me feeling groggy. I have trazodone, but that makes me feel like a zombie.

If anyone has good reasons to use it daily or some experiences to share, I’d love to hear!

Edit: I take around 1 mg each night, and I use a third-party-tested brand. My sleep quality is good, and I wake up feeling rested, although sometimes I find it hard to get up. I’m an insomniac, so feeling rested is pretty new to me. I’ve noticed that taking it about 3 hours before bed works best, but I’m curious if daily use could be causing the anxiety I’ve been having or why waking up has been hard. Tried skipping it one night, and my insomnia came right back. Any ideas?

Melatonin is actually a hormone. It affects more than just sleep, as it can also impact things like body temperature, blood sugar, and blood vessel tone, which is the tightness or relaxation of your blood vessels. The tricky part is that melatonin isn’t regulated like a drug, so there’s no FDA oversight.

Studies have shown that melatonin products often don’t have consistent doses, and some even contain other ingredients like serotonin. This can cause issues, especially for people on certain medications. It’s important to be cautious since taking an unknown dose over time could have effects on your heart, blood vessels, and brain. Many people think melatonin is totally safe because it’s natural, but it’s worth remembering there’s still a lot we don’t know about its long-term effects.

@Zan
Thanks for your reply. Could you talk a bit more about how it affects body temperature, blood sugar, and blood vessels? The article doesn’t go into much detail.

I’m a medic in the UK, and I find it frustrating that we can prescribe melatonin in hospitals but not in the community, where GPs can’t prescribe it. Instead, people are often given alternatives like amitriptyline, which has been linked to cognitive issues later in life and has side effects like sedation and constipation—especially problematic for brain injury patients.

Some herbal supplements, like valerian, can mess with other medications and might even affect liver health. Magnesium is another good option, and using it as a topical cream can work well.

I personally find melatonin patches effective, though it’s a hassle to find good ones here. Research shows that patches can release melatonin gradually, which might be more effective for staying asleep. I think melatonin has benefits, like antioxidants, which might lower cancer risk. Studies have even shown a link between melatonin and better fertility in women.

Yes, it’s a hormone, so I wouldn’t give it to kids without a specialist’s advice. But compared to some other meds for sleep, I think melatonin can be safer. Lifestyle changes, like dimming lights or morning sunlight, can also help. Andrew Huberman and Dr. Foster from Oxford have some good resources on circadian rhythm.

If you’re using melatonin, make sure it’s from a reputable source. I used to trust Kind Patches, but they’re hard to find in the UK now. Just be mindful of the dose and where you’re getting it.

@Darwin
What a great response, thanks for all the info. As a long-time insomnia sufferer, I’ve tried many meds, but now I’m using low-dose 4 mg doxepin. Do you have any thoughts on long-term use of this? Appreciate any insights!

@Darwin
Thanks for replying! I haven’t built any tolerance to it yet. I take 1 mg every night and sleep through the night. I usually go with Life Extension as a brand. Without it, I find it tough to get to sleep and stay asleep. I think it’s also improved my mood overall.

@Darwin
Melatonin helps people fall asleep, but it doesn’t really help with staying asleep. Using it every night may not harm you, but it’s not addressing the underlying issues causing sleep trouble. Antioxidants in melatonin aren’t fully proven either.

@Milan
> it’s not addressing the underlying issues causing sleep trouble

Can you explain a bit more about what it might be disrupting?

Haze said:
@Milan
> it’s not addressing the underlying issues causing sleep trouble

Can you explain a bit more about what it might be disrupting?

You’ll have to do your own research. Not going to put too much effort here on a Sunday morning.

@Milan
> You’ll have to do your own research.

You made a claim that it’s “disrupting things within” without explaining what that means. It’s a bit confusing when you won’t clarify.

Haze said:
@Milan
> You’ll have to do your own research.

You made a claim that it’s “disrupting things within” without explaining what that means. It’s a bit confusing when you won’t clarify.

It’s just Sunday morning on this forum, nothing I’m putting too much energy into. Go out and enjoy the day!

@Milan
I’d suggest backing up claims with some evidence. But yes, go enjoy your Sunday!

Haze said:
@Milan
I’d suggest backing up claims with some evidence. But yes, go enjoy your Sunday!

Lovely fall day here. I’ll stick with not taking suggestions from online forums too seriously.

@Milan
Ha! You’re being a bit childish.

@Milan
It actually does help me stay asleep as well.

In the bigger picture, taking an over-the-counter hormone every day for a long time might mean it’s time to check in with an endocrinologist to see if it’s the best option.

I can’t “explain” something that’s not true! Melatonin is generally safe for daily use.

Haze said:
I can’t “explain” something that’s not true! Melatonin is generally safe for daily use.

This is actually the kind of answer I was hoping for!

Ali said:

Haze said:
I can’t “explain” something that’s not true! Melatonin is generally safe for daily use.

This is actually the kind of answer I was hoping for!

Melatonin doesn’t down-regulate its own production, so there’s no need to worry about that. But it can potentially lower androgen levels, which might affect people with pre-existing hormone issues. For most, though, it’s not a problem.

It might be better to focus on boosting your natural melatonin production.