When seeing hormone-related patients, I am often asked, "I heard that taking melatonin is good for nerve cells or the brain—is that true?" Usually it is something they came across in an article or broadcast, and many of them thought of melatonin as their sleep grew lighter in menopause. To state the conclusion first, the aspect of melatonin helping sleep has relatively accumulated evidence, but the part about "protecting brain cells" still remains at the stage of animal experiments and mechanism research. This article, so as not to overlap with the menopausal insomnia story already covered, tries to honestly point out—centered on the level of evidence—to what extent the neuro/brain aspect of melatonin has been proven.
Why melatonin comes to mind in menopause
There are two backgrounds to melatonin becoming a topic around menopause. One is that melatonin secretion itself decreases with age, and the other is that during the menopausal transition, sleep grows lighter and waking during sleep becomes more frequent.
Melatonin is secreted from the brain's pineal gland and serves as a signal announcing night and day. Several review studies report a tendency for melatonin secretion to decrease during aging and the menopausal transition, and see this as able to explain part of the sleep problems of this period (Springer review, 2023). In the exam room, complaints of "I used to fall asleep the moment my head hit the pillow, but lately I keep waking at dawn" increase markedly around menopause, and it is also a period when such changes in the circadian rhythm overlap with hormonal change.
However, the fact that melatonin decreases and the claim that "taking melatonin protects the brain" are stories on entirely different levels. The former is an observed phenomenon, and the latter is an assertion about therapeutic effect; to narrow the distance between the two, the backing of clinical trials in humans is needed. If you are curious about the overall physical changes of menopause, also referring to the article organizing menopausal body changes, symptoms, and causes helps you grasp the flow.
Where does the 'brain cell protection' seen in articles and broadcasts come from?
Articles and broadcasts in domestic media introducing melatonin's nerve-cell protection or brain-health effects were in fact not few. Explanations like "melatonin stimulates nerve cell differentiation," "melatonin is the key to clearing beta-amyloid, the brain's waste," and "it helps prevent dementia" are typical.
The starting point of such reports is, in most cases, animal experiments, cell experiments, and mechanism research. It is true that melatonin has a strong antioxidant action, and that in animal models it was observed to reduce beta-amyloid burden or oxidative stress. The problem is that whether these results apply equally to humans has not yet been confirmed. One comprehensive review points out that melatonin is a noteworthy candidate in Alzheimer's-related pathology, but a considerable part of the evidence came from animal and cell experiments, and there is as yet no study that directly looked at its effect on beta-amyloid burden in humans (Molecular Psychiatry review, 2024).
The fact that something "was in an article" and the fact that "a therapeutic effect has been proven" are different. That a possibility was seen in mechanism research, and that a human takes it and the brain is actually protected, are evidence at entirely different stages.
In other words, it is safer to understand that much of the melatonin brain-health story seen in the media is a case of compressing "a possibility still under research" and conveying it as if it were "an already established effect."
Dividing the stages of evidence for melatonin and the brain
Research on melatonin and the nervous system/brain differs greatly in the weight of evidence by stage. Even for the same statement that "melatonin is good for the brain," the reliability differs depending on which stage of research the story came from. Let me organize it in the table below.
| Evidence stage | What it covers | Current level |
|---|---|---|
| Mechanism research | Antioxidation, beta-amyloid, circadian signals | Presents hypotheses and mechanisms |
| Animal/cell experiments | Nerve cell protection, waste clearance | Application to humans unconfirmed |
| Clinical trials | Sleep/cognition changes in humans | Limited, mixed results |
| Clinical recommendation | Recommended as standard treatment | Not recommended for neuroprotection purposes |
As the table shows, melatonin's neuroprotective possibility remains in the upper two stages and has not yet come down to the lower two stages. The interesting hypothesis is also presented that the brain's waste-clearance pathway called the glymphatic system becomes active during deep sleep and that melatonin is associated with this process, but this too is not a stage sufficiently verified in humans (Springer review, 2023). From clinical experience, when I explain this distinction, many people calmly accept it, saying "So for now it's at the stage of hope."
What do the Alzheimer's and Parkinson's studies tell us?
In clinical trials in humans, melatonin's effect was not as clear as hoped. Rather than a large effect of neuroprotection, partial signals are observed in the narrow area of sleep.
In a study administering sustained-release melatonin to Alzheimer's patients for 24 weeks, some cognitive/daily-living indicators improved, but there was no difference in the core cognitive assessment, and the effect was reported to be a bit more pronounced especially when insomnia accompanied it (Wade et al., 2014). A network meta-analysis synthesizing several randomized studies suggested the possibility of a slight improvement in cognitive indicators with medium-to-low dose, medium-term administration, but the heterogeneity between studies and the limitations of indirect comparison were also pointed out (Tseng et al., 2022). Conversely, there were also studies that failed to improve sleep or agitation symptoms (Gehrman et al., 2009). For sleep disorders in Parkinson's disease, evidence for improving sleep quality is accumulating to some degree, but neuroprotection itself is still under research.
In summary, the human evidence is closer to "it can help indirectly by aiding sleep in some who have accompanying insomnia" than to "it protects nerves." It means that you receive help through the process of the brain recovering during sleep, and that it is hard to assert that melatonin directly protects nerve cells.
If you are curious about why sleep itself is important for menopausal health and what can follow when sleep collapses, we recommend also reading the article dealing with the effect of insomnia on the cardio-cerebrovascular system. If you are unsure whether your own sleep pattern is due to menopause, feel free to leave your sleep concern first by chat.
If you are thinking of melatonin for the purpose of menopausal sleep
Considering melatonin because sleep grows lighter in menopause can be a natural option. However, expecting melatonin to be an all-purpose solution to menopausal sleep problems is at a distance from the evidence.
A recent systematic review and meta-analysis in postmenopausal women reported cases where melatonin did not show clear improvement in sleep quality, overall menopausal symptoms, or mood indicators (postmenopausal women melatonin meta-analysis, 2024). On the other hand, there is also a view that it can help in sleep problems of the type where the circadian rhythm is disrupted, so in the end expectations should be set differently depending on "what kind of sleep problem" it is. To organize the checklist that helps when considering melatonin:
- First distinguishing whether the cause of insomnia is a menopausal symptom itself such as hot flashes or night sweats, or a circadian-rhythm problem
- Interactions with medications you take or pre-existing conditions must be checked
- The formulation, such as sustained-release, and the dose vary depending on the symptom pattern
- Taking it for the purpose of "brain cell protection" cannot be recommended with current evidence
In particular, in Korea, melatonin is not permitted as a health-functional-food ingredient, so it can only be used by a doctor's prescription. Using overseas-purchased products or products named "plant-based melatonin" for the purpose of treating insomnia or disease is hard to recommend. If you want to check menopausal hormonal changes overall and sleep together, it is safer to first confirm your own state through menopausal hormone care or menopause screening.
Honestly matching expectations comes first
The story of melatonin and the brain is attractive, but the evidence so far is somewhere between "possibility" and "proof." The neuroprotective effect is at the animal/mechanism research stage and has not yet been established in humans, and the human evidence remains mainly at indirect help through sleep in some who have accompanying insomnia.
So in the exam room, I explain melatonin not as "a medicine that guards the brain" but as "one of the options that, by helping sleep, assists in spending the menopausal period a little more comfortably." Rather than being swayed by exaggerated phrases, it is far more important to accurately grasp your own sleep and hormonal state and find a method that suits it. If you are wondering whether taking melatonin is appropriate for you or whether another method is better, please feel free to inquire through 갱년기 수면 상담 신청하기.
Author: Lee Donghee Chief Director · Obstetrician-Gynecologist · View provider profile
First published November 23, 2025 · Last reviewed May 30, 2026
References: Molecular Psychiatry melatonin/Alzheimer's review (2024), Springer melatonin/brain waste-clearance review (2023), Wade et al. (2014), Tseng et al. (2022), Gehrman et al. (2009), postmenopausal women melatonin sleep meta-analysis (2024)
This article is intended to provide general health information and does not replace individual diagnosis or treatment. If you have symptoms, please consult through a medical visit.