Medically reviewed by Dr. Reina Punj, MBBS, PG Diploma in Endocrinology (University of South Wales), Lead Physician, Excelgenics Clinical Panel.
How much magnesium glycinate should you take? For healthy adults, the magnesium glycinate dose from supplements should stay at or below 350 mg of elemental magnesium a day, the upper limit the US National Institutes of Health (NIH) sets for magnesium from supplements, unless a doctor advises more. As for the best time to take magnesium glycinate, there is no proven best time: many people take it in the evening, but taking it every day at the dose on the label matters more than the clock.
This article explains magnesium bisglycinate dosage per day, how to read the label, when to take magnesium glycinate, and who should check with a doctor first. For a broader overview of forms and safety, see our Magnesium Supplements Guide.
How much magnesium glycinate should I take?
Start with how much magnesium you need in total. The Recommended Dietary Allowance (RDA) covers magnesium from food and supplements combined.
| Adults | India (ICMR-NIN 2020) | US (NIH) |
|---|---|---|
| Men | 440 mg a day | 400 mg (ages 19–30); 420 mg (31 and over) |
| Women | 370 mg a day | 310 mg (ages 19–30); 320 mg (31 and over) |
| Pregnancy | Not given in the ICMR-NIN summary | 350–360 mg, depending on age |
Nuts, seeds, whole grains, pulses and green leafy vegetables all supply magnesium, so a supplement is meant to top up your diet, not replace it. That is why the supplement dose is usually lower than the full RDA.
Magnesium glycinate dose: the 350 mg upper limit
The NIH Office of Dietary Supplements sets the Tolerable Upper Intake Level for supplemental magnesium at 350 mg a day for adults. This limit applies only to magnesium from supplements and medicines. Magnesium from food does not count towards it, because healthy kidneys remove the excess in urine.
Going above the limit makes side effects more likely. High doses of magnesium from supplements or medicines can cause diarrhoea, nausea and stomach cramps. Remember to add up every source: multivitamins, some antacids and some laxatives also contain magnesium.
Elemental magnesium vs compound weight on the label
This is the most common source of confusion with magnesium glycinate dosing. Magnesium glycinate (also called bisglycinate) is magnesium bound to the amino acid glycine. The compound weighs much more than the magnesium it contains, and only the elemental magnesium figure tells you how much magnesium you actually get. The NIH notes that US supplement labels declare elemental magnesium, not the weight of the whole compound. Labels in India and elsewhere are not always as clear, so look for the words "elemental magnesium" or "providing ... mg magnesium".
For example, Magneva Magnesium Bisglycinate 350mg + Vitamin B6 provides 350 mg of elemental magnesium per tablet. If a label shows only a large compound figure (such as "magnesium glycinate 1,000 mg") without the elemental amount, you cannot tell how much magnesium it supplies.
How much magnesium bisglycinate per day?
- Follow the label. The right magnesium bisglycinate dosage per day is the one on your product's label, provided the elemental magnesium stays within 350 mg from all supplements combined.
- Do not stack products. If one product already provides 350 mg, do not add another magnesium supplement unless your doctor advises it.
- Splitting doses. Some products are designed as two or more tablets a day, which some people spread across the day. We found no good-quality trials showing that splitting a magnesium glycinate dose changes how well it works. If your product is one tablet a day, take it as directed rather than cutting it.
- Children. Upper limits for children are lower and vary by age, so ask a doctor before giving magnesium supplements to a child.
When to take magnesium glycinate
Honest answer: the research on timing is limited. The NIH fact sheet does not recommend a time of day, and we did not find trials comparing morning and evening doses of magnesium glycinate.
Evening use is common practice because many people take magnesium as part of a wind-down routine. The sleep research itself is modest: a 2021 review of three small trials in 151 older adults with insomnia found that magnesium shortened the time taken to fall asleep by about 17 minutes compared with placebo, with no significant change in total sleep time, and rated the evidence as low to very low quality. Our article on magnesium for sleep looks at this in more detail.
Best time to take magnesium glycinate in practice
- If you take it as part of your evening routine: 30–60 minutes before bed is a common choice, and it is what the Magneva label suggests.
- If you are more likely to remember it in the morning: that is fine too. Taking it at a time you will stick to matters more than the exact hour.
- If you take medicines that interact with magnesium: choose a time that keeps the right gap (see the table below).
With or without food?
Magnesium glycinate can be taken with water on its own or with a light meal. If it upsets your stomach, taking it with food may help.
Consistency matters most
Magnesium is not a quick fix. Take it daily at the same time so it becomes a habit, and give it several weeks before judging whether it suits you.
Who should get medical advice first
Speak to your doctor before taking magnesium glycinate if you:
- have kidney disease or reduced kidney function. The kidneys clear excess magnesium, and the risk of magnesium toxicity rises when they do not work well;
- are pregnant or breastfeeding;
- take regular medicines, especially those listed below;
- have been advised to take magnesium for a medical reason, as your doctor may set a different dose.
Spacing magnesium from medicines
| Medicine | What to do (NIH guidance) |
|---|---|
| Tetracycline antibiotics (e.g. doxycycline) and quinolone antibiotics (e.g. ciprofloxacin) | Take the antibiotic at least 2 hours before, or 4–6 hours after, magnesium |
| Oral bisphosphonates (for bone health) | Separate from magnesium by at least 2 hours |
| Diuretics | Some increase magnesium loss and some reduce it, so ask your doctor |
| Proton pump inhibitors (acid-reducing medicines) taken for more than a year | Long-term use can lower blood magnesium; your doctor may check your levels |
If you are unsure, your pharmacist can help you plan the timing. For tips on comparing products, read how to choose a magnesium bisglycinate supplement in India.
Frequently asked questions
Is 350 mg of magnesium glycinate too much?
350 mg of elemental magnesium a day is the NIH upper limit for magnesium from supplements in adults, so it is the maximum, not a target to exceed. Make sure it is your total from all supplements, and check with your doctor first if you have kidney problems.
Can I take magnesium glycinate every night?
Yes, magnesium supplements are designed for daily use at the dose on the label. Do not take more than the label dose unless your doctor advises it.
Can I take magnesium glycinate in the morning?
Yes. There is no good evidence that one time of day is better. Choose the time you can stick to and that keeps the right gap from any interacting medicines.
How long before bed should I take magnesium glycinate?
If you take it in the evening, 30–60 minutes before bed is a common choice. There is little research on exact timing, so this is practical guidance rather than a proven rule.
Is magnesium glycinate the same as magnesium bisglycinate?
Usually, yes. "Bisglycinate" spells out that each magnesium atom is bound to two glycine molecules. Compare products by the elemental magnesium per serving, not the name.
References
- National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals (updated 6 January 2026). ods.od.nih.gov
- ICMR-National Institute of Nutrition. Nutrient Requirements for Indians: Recommended Dietary Allowances and Estimated Average Requirements, a brief note (2020). nin.res.in
- Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a systematic review and meta-analysis. BMC Complementary Medicine and Therapies. 2021;21:125. doi:10.1186/s12906-021-03297-z
This article is for general education and is not medical advice. Food supplements are not intended to diagnose, treat, cure or prevent any disease. Consult a qualified healthcare professional before starting any supplement, particularly if you are pregnant, breastfeeding, have a medical condition or take medication.
