Medical disclaimer: SnoozeVerdict summarizes what people say about sleep supplements on Reddit. It is not medical advice, and nothing here is meant to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the Food and Drug Administration. Talk to your doctor or pharmacist before starting a supplement, especially if you are pregnant, take medicines (including sleep or mood medicines), or have a medical condition. Poor sleep that lasts for months, loud snoring or gasping at night, or falling asleep during the day while driving or working needs a doctor, not a supplement. Full disclaimer.

Question · Deep sleep

Does magnesium improve deep sleep?

Many say yes, going by Reddit owner reports: 30 of 36 rated comments from people who talk about deep or restful sleep describe a good experience with Magnesium, and 3 describe a poor one. That is self-reported experience, not proof that it works, and results vary from person to person.

Magnesium, Deep sleep	Owner comments
Rated comments in this context	36
Positive	30 (83%)
Negative	3 (8%)
Describe an unwanted effect	5
Context rating (small samples pulled to the average)	3.8

Magnesium (form not stated) overall: 4.2 from 938 owner comments in Reddit sleep, insomnia and supplement communities, May 2026 to October 2026.

What the research says

Magnesium is an essential mineral involved in hundreds of enzyme reactions; many people do not get the recommended amount from food.^{[NIH Office of Dietary Supplements]}
A small 2012 double-blind trial in older adults with insomnia compared 500 mg of magnesium a day with placebo for 8 weeks.^[PubMed]
A 2021 meta-analysis of trials in older adults rated the evidence as low quality.^[PubMed]

Safety

The NIH upper limit for magnesium from supplements is 350 mg a day for adults unless a doctor advises more; higher doses commonly cause diarrhea, and people with kidney disease are at higher risk of magnesium build-up.^{[NIH Office of Dietary Supplements]}
Magnesium can reduce absorption of some antibiotics and osteoporosis drugs, so doses are usually spaced apart.^{[NIH Office of Dietary Supplements]}

Good experiences

4/5 Deeper sleep
“Magnesium -- I started taking it for the muscle cramps after long runs and it turned out to help with general sleep quality too, which I wasn't expecting.”

owner comment via r/Supplements · 2026-06-15 · 42 upvotes

4/5 Deeper sleep
“and i started taking magnesium before bed, the glycinate kind, it helped with the body aches and sleep quality”

owner comment via r/Supplements · 2026-08-14 · 20 upvotes

4/5 Morning grogginessSide effects
“I take 10mg of Davigo and 300mg of magnesium every night and sleep like a baby.”

owner comment via r/insomnia · 2026-08-28 · 7 upvotes

Poor experiences

2/5 Morning grogginessSide effects
“Some people do report feeling more rested with slightly less sleep after starting magnesium, but I'd be careful not to assume magnesium is directly “reducing sleep need.” It may be helping sleep quality for you, or there may be other factors involved.”

owner comment via r/sleep · 2026-05-15 · 1 upvotes

2/5 Side effects
“Because when you have an allergy and get serotonin or magnesium, you wake up with brain fog.”

owner comment via r/sleep · 2026-07-15 · 1 upvotes

How reports compare in other contexts

Context	Rated comments	Positive	Negative
Falling asleep	41	37	3
Morning grogginess	30	12	14
Staying asleep	25	20	5
Anxiety at night	23	15	7
Vivid dreams	9	3	4

More on Magnesium

Talk to a doctor about new, severe or lasting symptoms, and to a pharmacist before combining supplements with medicines.