Best Time to Take Magnesium Glycinate (and Any Magnesium)
Take magnesium glycinate at the same time every day, with a meal. No study shows that morning or night works better, so pick the time you will remember. If you take it for sleep, take it with dinner or an evening snack.
| Your reason | When | Why |
|---|---|---|
| To get enough magnesium | Any time, with a meal | No study shows one hour beats another. Food makes stomach upset less likely. |
| Sleep | With dinner or an evening snack | Sleep trials gave magnesium daily; none compared times. Evening keeps it tied to bedtime. |
| Constipation | When a bowel movement in 30 minutes to 6 hours suits you | That is what magnesium laxative labels say (milk of magnesia, liquid citrate). Glycinate is not a laxative. |
| You take other medicines | Hours apart from them | Magnesium binds some antibiotics, osteoporosis drugs and thyroid pills. The spacing rules. |
| It upsets your stomach | Half in the morning, half at night | High doses cause diarrhea (NIH), and small doses are absorbed better than one big one (Schuchardt 2017). |
Morning or night?
Either works. We found no trial that compared a morning dose of magnesium with an evening one. What the research does show is that your body handles several small doses better than one big one: a review of magnesium absorption found more of it is absorbed when it is taken in small amounts through the day (Schuchardt 2017).
So choose the time you will stick with:
- Night if you take magnesium for sleep, or you already take other pills with dinner.
- Morning if you forget pills at night, or you take a medicine at night that magnesium should stay away from.
- Both if you take more than about 200 mg, or one dose loosens your stools.
Best time of day to take magnesium glycinate
With a meal, at the same time each day. Nature Made’s glycinate label says to take 2 capsules daily “with water and a meal.” Many people take glycinate in the evening because they take it for sleep. That is a habit, not a tested rule. A dose of 200 mg, like our pick, Revive MD’s glycinate, fits in one sitting; over that, split it.
Glycinate is not on NIH’s list of forms most often reported to cause diarrhea (carbonate, chloride, gluconate and oxide), which is one reason it is often called gentle on the stomach (NIH). How the forms compare.
With food or on an empty stomach?
With food. Both Nature Made labels, glycinate and citrate, say to take them with a meal. No trial tested glycinate with and without food. But the most common side effect of too much magnesium from pills is diarrhea, sometimes with nausea and cramps (NIH), and a meal plus a split dose is the easy way to make it less likely.
If you take magnesium for constipation, the advice changes. Magnesium laxatives work by leaving unabsorbed magnesium in the gut, which pulls in water (NIH). Their drug labels say they usually bring a bowel movement within 30 minutes to 6 hours. Do not use them every day without a doctor: very large doses of magnesium laxatives, usually more than 5,000 mg a day, are where dangerous magnesium levels have come from (NIH).
How to split each glycinate under the 350 mg limit
The upper limit for adults is 350 mg a day of magnesium from supplements and medicines. Food does not count toward it (NIH). Several glycinate labels direct more than that. Here is how each glycinate we link spreads across the day without going over.
| Product | Magnesium | Label says | Split it like this | Per 300 mg | Buy |
|---|---|---|---|---|---|
| Revive MD Magnesium Glycinate | about 100 mg a capsule | 2 capsules (200 mg) | 1 capsule with breakfast, 1 with dinner | $0.50 | Check price |
| Nature Made Magnesium Glycinate 200mg | 100 mg a capsule | 2 capsules a day, with a meal (200 mg) | 1 capsule with breakfast, 1 with dinner | $1.10 | Check price |
| KAL Magnesium Glycinate 350 | about 88 mg a capsule | 4 capsules (350 mg) | 2 capsules twice a day; that is the whole 350 mg | No list price | Check price |
| Thorne Magnesium Glycinate | 120 mg a capsule | 1 capsule, one to four times a day (up to 480 mg) | 1 or 2 capsules a day (120 or 240 mg); 3 would be 360 mg | $0.72 | Check price |
| BulkSupplements Magnesium Glycinate Powder | 300 mg in ¾ teaspoon | ¾ teaspoon (300 mg) | About ⅓ teaspoon twice a day; it is a glycinate and oxide blend | $0.19 | Check price |
Labels read on each brand’s page. KAL has no list price we could check. BulkSupplements’ label says its magnesium comes from glycinate and oxide together. Testing lists: Nature Made is on USP Verified; Revive MD is on Informed Sport (every batch is tested for drugs banned in sport, not a check of the label); Thorne’s capsules and BulkSupplements’ powder are on NSF/ANSI 173; KAL is on none we searched (checked October 14, 2026). Which glycinate is on which list.
Best time to take magnesium citrate
A citrate capsule or softgel is a daily supplement, just like glycinate: take it with a meal at a time you will remember. Nature Made Magnesium Citrate gives 250 mg in 2 softgels for $0.39 a day at list price, also USP Verified, and its label says to take them with a meal. Citrate can loosen stools at higher doses; if it does, split it or switch to glycinate. Glycinate vs citrate.
Liquid magnesium citrate from the pharmacy is a laxative, not a supplement. Its label says it usually works in 30 minutes to 6 hours.
How far apart from other medicines?
Magnesium sticks to some drugs in the gut, so less of the drug gets into your blood. The fix is spacing, not stopping:
- Antibiotics: take tetracyclines (such as doxycycline) or quinolones (such as ciprofloxacin) at least 2 hours before or 4 to 6 hours after magnesium (NIH).
- Osteoporosis drugs (bisphosphonates such as alendronate): take them at least 2 hours apart from magnesium (NIH).
- Thyroid pills (levothyroxine). In 15 healthy adults, magnesium aspartate taken at the same time cut the thyroid hormone absorbed by 12%; citrate cut it by 7%, too small to be sure. The authors advise taking levothyroxine apart from magnesium (Attinger 2025). The trial did not test how many hours apart; your pharmacist can tell you what suits your dose.
- Zinc. Only very high doses matter: 142 mg of zinc a day lowered magnesium absorption in one study (NIH). Normal zinc doses are fine.
- Other minerals. High doses of other minerals can lower magnesium uptake (Schuchardt 2017). If you take a large calcium or iron dose, spacing it from magnesium is a reasonable habit, though no trial has set a rule.
Some medicines lower your magnesium instead, such as heartburn pills (PPIs) and water pills. Those are on our side effects page.
How long until it works?
It depends on why you take it. Raising low magnesium takes steady daily doses, not one well-timed pill. The sleep trials ran for 3 to 8 weeks. How long magnesium takes to work.
Frequently Asked Questions
What is the best time of day to take magnesium glycinate?
Any time you will remember, with a meal. No study has compared morning with evening doses of glycinate. Nature Made’s label says to take its 2 capsules daily “with water and a meal.” If you take it for sleep, dinner or an evening snack covers both.
Should I take magnesium in the morning or at night?
Either. Taking it every day matters more than the hour. Night suits people who take it for sleep. Morning suits people who forget pills at night. If one dose upsets your stomach, take half in the morning and half at night.
Should magnesium be taken with or without food?
With food is the safer habit. The Nature Made glycinate and citrate labels both say “with water and a meal.” The main side effect of too much magnesium from pills is diarrhea (NIH). Splitting a larger dose helps too.
How long before bed should I take magnesium for sleep?
No sleep trial tested the timing, so there is no proven window. Taking it with dinner or an evening snack is a simple routine. In a review of 3 small trials in older adults, people on magnesium fell asleep about 17 minutes faster, with low-quality evidence (Mah 2021). Magnesium and sleep.
What should you not take magnesium with?
Some antibiotics, osteoporosis drugs and thyroid pills. Antibiotics: take tetracyclines (such as doxycycline) or quinolones (such as ciprofloxacin) at least 2 hours before or 4 to 6 hours after magnesium (NIH). Osteoporosis drugs (bisphosphonates such as alendronate): take them at least 2 hours apart from magnesium (NIH). Take levothyroxine apart from magnesium too (Attinger 2025). Very high zinc (142 mg a day) can lower magnesium absorption (NIH). The full list.
What is the best time to take magnesium citrate?
With a meal, at a time you will remember. A 250 mg citrate serving, like Nature Made’s, is a daily supplement, not a laxative. Liquid magnesium citrate sold as a laxative is different: its label says it usually works in 30 minutes to 6 hours, so take it when that window suits you.
Can I take magnesium with vitamin D or other supplements?
Yes. Count the magnesium in every product, including multivitamins and calcium-magnesium tablets. Magnesium with vitamin D.
Can I take magnesium glycinate every day?
Yes, if the magnesium from all your supplements stays at or under 350 mg a day. If you have kidney disease, ask your doctor before you take magnesium. Weak kidneys cannot clear the extra, so it can build up (NIH).
Related Guides
- Magnesium dosage guide: how much to take by age and sex
- Magnesium side effects: diarrhea, the upper limit and every interaction
- Magnesium and sleep · magnesium with vitamin D · forms compared
- Best magnesium supplement · magnesium guide
Sources
- NIH Office of Dietary Supplements. Magnesium fact sheet for health professionals (updated January 6, 2026).
- Schuchardt JP, Hahn A. Intestinal absorption and factors influencing bioavailability of magnesium: an update. Curr Nutr Food Sci. 2017. PubMed 29123461
- Attinger MC, et al. Drug-drug interactions of levothyroxine with magnesium citrate and magnesium aspartate (ThyroMag trial). Clin Transl Sci. 2025. PubMed 41221788
- Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults. BMC Complement Med Ther. 2021. PubMed 33865376
- Laxative onset: Milk of Magnesia (magnesium hydroxide) and magnesium citrate oral solution drug labels, DailyMed.
- Label directions: each brand’s product page, read October 15, 2026. Prices: each brand’s own list price, checked October 14, 2026.