Sweet Dreams Are Made of Zzz’s: Melatonin’s Effects on the Brain
- R.D. Ordovich-Clarkson
- Apr 14
- 4 min read
By Dr. Randall D. Ordovich-Clarkson, MD
As part of a school project on the effects of melatonin, I was recently contacted by a student looking to understand how this popular sleep aid interacts with the brain. They asked some excellent, thoughtful questions about the neurological impact of melatonin—ranging from how it works to its long-term effects and potential pros and cons. I was happy to respond, and I thought our exchange would be useful for others curious about melatonin as well.
Here’s how that conversation went:
Good morning Dr. Clarkson, my name is [name redacted]. I’m contacting you regarding my Senior project where I'm studying the effects of melatonin on high school students' everyday schedules. I’d like to ask you some questions if you don’t mind. For some context, the melatonin utilized in the experiment is Natrol brand, drug-free, 3mg, 5mg, and 10mg melatonin gummies. First, I'd like to get your opinion on the neurological impacts of melatonin. How does melatonin affect the brain? What would be the long-term effects of taking melatonin? Lastly, In your expert opinion, what are the Pros and Cons of taking melatonin neurologically? I appreciate you agreeing to be a part of my research, and taking the time to respond to my inquiries. Thank you, Dr. Clarkson, I await your response.
Hello [name redacted]!
I’m happy to help you with your project! Here are my responses to your questions. I also provided a few citations to help give you additional resources as well.
Q: How does melatonin affect the brain neurologically?
A: That’s a great question. So, melatonin is a hormone your brain naturally produces—specifically in the pineal gland. Think of it as your body’s own “sleep signal.” When it starts getting dark, melatonin levels rise, telling your brain it’s time to sleep. When it’s light, those levels drop, and that helps keep your sleep-wake cycle, or circadian rhythm, in sync.
When you take melatonin supplements—like the Natrol gummies you mentioned, whether it’s 3mg, 5mg, or 10mg—you’re basically giving your brain an artificial signal that it’s time to wind down. It binds to specific receptors in your brain to promote drowsiness. But here’s the kicker: most supplements give you way more melatonin than your body would ever produce naturally.
UC Davis Health actually points this out, saying that “more is not better” when it comes to melatonin. Even small doses can be effective, and taking too much might not make you sleepier—it could just leave you groggy or give you weird dreams (UC Davis Health, 2025).
Q: What are the long-term effects of taking melatonin?
A: This one’s a little trickier because the science is still evolving. One concern is that if you take melatonin for a long time, your brain might reduce its own production of it—a process called negative feedback. It’s kind of like how some guys who take testosterone supplements end up producing less of their own testosterone.
That said, research suggests melatonin is actually pretty safe when taken responsibly over the long term. One major review looked into this and found that adverse reactions were rare, even with chronic use (Givler et al., 2023). They emphasized that while we should be mindful about dosing, melatonin doesn’t seem to be harmful when used correctly over time.
Q: In your expert opinion, what are the pros and cons of melatonin neurologically?
A: Alright, here’s my take, both from research and personal experience.
Pros:
It’s super helpful for resetting your brain’s internal clock—great for jet lag or if you’re a night owl trying to shift to an earlier schedule.
It can help people fall asleep faster and improve sleep quality, especially if they have insomnia or delayed sleep phase issues (Givler et al., 2023).
Cons:
Like I mentioned, the doses in supplements are often much higher than what your body needs. That can lead to grogginess, headaches, or vivid dreams the next day. I personally stopped using melatonin for that reason—it just gave me a headache and didn’t do much for my sleep.
There’s also the possibility that long-term use could mess with your natural melatonin cycle, although the evidence for that is still up in the air (UC Davis Health, 2025).
Q: So would you recommend it?
A: Honestly? I’d say it depends on the person. For someone who’s dealing with jet lag or just can’t fall asleep despite good sleep habits, a low dose of melatonin—maybe 1–3mg—is worth trying. But I wouldn’t recommend taking 10mg every night long-term unless it’s supervised by a doctor. And just because it’s sold over-the-counter doesn’t mean more is better.
Everyone’s biochemistry is different, and what didn’t work for me might work well for someone else. The key is using it wisely and not relying on it as a permanent fix for sleep issues.
References
Givler, D., Givler, A., Luther, P. M., Wenger, D. M., Ahmadzadeh, S., Shekoohi, S., Edinoff, A. N., Dorius, B. K., Jean Baptiste, C., Cornett, E. M., Kaye, A. M., & Kaye, A. D. (2023). Chronic administration of melatonin: Physiological and clinical considerations. Neurological International, 15(1), 518–533. https://doi.org/10.3390/neurolint15010031
UC Davis Health. (2025, February). Melatonin and your sleep: Is it safe, what are the side effects, and how does it work. https://health.ucdavis.edu/blog/cultivating-health/melatonin-and-your-sleep-is-it-safe-what-are-the-side-effects-and-how-does-it-work/2025/02
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