Some evidence suggests melatonin may help improve sleep-wake cycles, sundowning symptoms, and cognitive performance in people with dementia, but more research is necessary.

Melatonin is a hormone produced by the pineal gland in the brain. It helps regulate the circadian rhythm, also known as the sleep-wake cycle. Melatonin is also available as a dietary supplement, which people may take to help with certain conditions, such as sleep disorders.

Some research suggests that melatonin may benefit people with dementia by improving sleep-wake cycles and cognitive performance. However, other research has found no evidence to support this.

More research is necessary to understand whether melatonin is safe or effective in people with dementia. Some experts do not recommend melatonin for people with dementia, as it may increase the risk of falls.

Timed melatonin treatment at specific circadian rhythm phases may improve sleep-wake patterns in people with Alzheimer’s disease.

People with Alzheimer’s disease experience significant changes in the body’s natural rhythms, including the circadian rhythm, and may have disturbances in their sleep-wake cycle.

According to a 2022 article, melatonin may help with sleep disturbances associated with neurodegenerative diseases such as dementia.

Another recent 2025 review found that melatonin is relatively safe for those with cognitive impairment, and the authors recommend it for mild cognitive impairment (MCI). They suggest it is taken between 8:30 and 9 PM for 13 to 24 weeks. However, it’s important to note that MCI appears before dementia.

Melatonin may increase the risk of falls or other negative events, particularly for older adults.

According to a 2022 article, there is a lack of research on the long-term use of melatonin. In animal studies, high doses of melatonin are necessary to achieve its potential benefits, but the long-term effects are unknown.

The article notes that melatonin is generally safe for short to medium use, from a few weeks to under 18 months. However, there are no human studies assessing its safety long term.

The NHS in the UK notes that melatonin supplementation should only be for a maximum of 13 weeks for the treatment of adult sleep problems.

Melatonin is available over the counter or online as a food supplement. But keep in mind these products are not regulated in the same way as clinical drugs. This means the quality, dosage, and bioavailability of melatonin can vary between products, and safety and effectiveness are not guaranteed.

When considering taking melatonin, consult a doctor about the potential benefits and risks, as well as any interactions with other medications.

Discuss the possible effects of melatonin on sundowning symptoms, sleep problems, cognitive function, or other symptoms of dementia.

If an individual taking melatonin notices any side effects or feels there is an increased risk of falls, speak with a doctor about stopping melatonin supplementation.

Does melatonin cause dementia?

No evidence suggests melatonin has any effect on the risk of developing dementia.

Why do doctors not recommend melatonin for dementia patients?

Experts may not recommend melatonin to people with dementia due to an increased risk of falls and other adverse events. Although generally safe in healthy people, it is unclear whether melatonin is safe or effective in those with dementia.

What is the best melatonin dosage for people with dementia?

The melatonin dosage in clinical trials for people with dementia varies. Further research is necessary to understand whether there is an ideal dosage for people with dementia.

Dementia resources

Visit our dedicated hub for more research-backed information and in-depth resources on dementia.

Melatonin may have potential benefits for people with dementia, including improving sleep and wake cycles, reducing sundowning symptoms, and enhancing cognitive performance.

However, research is mixed on the effectiveness of melatonin for people with dementia, and experts may not recommend it due to an increased risk of falls. Long term safety trials must also be conducted.