Research shows magnesium supplementation between 125–600 mg daily can deliver real benefits—but the right dose depends on what you’re trying to address.
Magnesium is involved in over 300 biochemical reactions in your body. It helps with energy production, protein synthesis, brain function, bone strength, and muscle and heart regulation. You’ll find it naturally in nuts, leafy greens, and dairy products.
But many people fall short. The typical Western diet, heavy on processed foods and refined grains, often lacks magnesium-rich foods like spinach and legumes.
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Available on the App StoreSupplementing can help with everything from better sleep to blood sugar control to constipation relief. Here’s how to choose the right dose for your situation.
In this article
Recommended daily intake by age
Many people don’t get enough magnesium from food alone. Here are the recommended daily amounts:
Female
- Birth to 6 months: 30 mg
- 7–12 months: 75 mg
- 1–3 years: 80 mg
- 4–8 years: 130 mg
- 9–13 years: 240 mg
- 14–18 years: 360 mg
- 19–30 years: 310 mg
- 31+ years: 320 mg
Male
- Birth to 6 months: 30 mg
- 7–12 months: 75 mg
- 1–3 years: 80 mg
- 4–8 years: 130 mg
- 9–13 years: 240 mg
- 14–18 years: 410 mg
- 19–30 years: 400 mg
- 31+ years: 420 mg
Pregnant women 18 or older need 350–360 mg daily.
Certain conditions increase deficiency risk: high blood pressure, type 2 diabetes, and alcohol use disorder are all associated with lower magnesium levels.
An umbrella review analyzing systematic reviews and meta-analyses found strong evidence that magnesium supplementation decreases hospitalization risk in pregnant women and reduces migraine frequency/intensity. Higher magnesium intake was also associated with lower risk of type 2 diabetes and stroke.1
Summary: Adults need 310–420 mg of magnesium daily, depending on age and sex. Many people don’t reach this through diet alone.
Suggested read: 10 Healthy Magnesium-Rich Foods to Boost Your Intake
Types of magnesium supplements
Not all magnesium supplements are created equal. The key difference is absorption—how much actually gets into your bloodstream.
Magnesium glycinate
Well-absorbed with minimal laxative effect. A good choice for general supplementation and sleep support. It’s absorbed in a different part of your intestine than most other forms.
Magnesium citrate
Good absorption and high water solubility. Often used as a laxative before medical procedures. Also available in pill form for daily supplementation.
Magnesium chloride
Absorbs well and comes in both oral and topical (oil) forms. Research on skin absorption is still limited.
Magnesium oxide
Contains the most elemental magnesium per dose but absorbs poorly because it’s nearly insoluble in water. Better for constipation than for raising blood levels.
Magnesium hydroxide
Known as milk of magnesia. Used primarily as a laxative and antacid.
Magnesium gluconate
Animal studies suggest high absorption rates, though human research is limited.
Magnesium aspartate
Another well-absorbed form commonly found in supplements.
Learn more: Types of magnesium supplements
Summary: For general supplementation, magnesium glycinate, citrate, or chloride offer the best absorption. Oxide and hydroxide work better for constipation.
Magnesium for constipation
Magnesium hydroxide (milk of magnesia) and magnesium citrate are the go-to options for constipation relief. They work by pulling water into your intestines, softening stool and easing passage.
Dosing:
- Magnesium citrate: 240 mL mixed with water, taken orally
- Magnesium hydroxide: Follow product label instructions
Stick to recommended doses. Too much can cause watery diarrhea and electrolyte imbalances.
Milk of magnesia works well for occasional constipation but isn’t recommended for chronic use.
Summary: Magnesium citrate or hydroxide can relieve constipation. Follow label instructions and don’t exceed recommended doses.
Magnesium for sleep
Magnesium helps regulate neurotransmitters involved in sleep. Low levels have been linked to poor sleep quality.
A systematic review and meta-analysis of randomized controlled trials found that older adults taking oral magnesium supplements fell asleep 17 minutes faster on average compared to placebo. The studies used doses under 1 gram taken up to three times daily.2
Another review found that 320–729 mg daily from magnesium oxide or citrate improved sleep onset in older adults with insomnia.
Magnesium glycinate may be particularly well-suited for sleep because it absorbs well without the laxative effect of other forms.
Related: Foods that help you sleep
Summary: 320–500 mg of magnesium daily may help you fall asleep faster. Glycinate and citrate forms work well for sleep support.
Magnesium for blood sugar
People with diabetes often have lower magnesium levels. High blood sugar increases magnesium loss through urine.
A systematic review and meta-analysis found that magnesium supplementation for at least four months significantly improved insulin sensitivity (HOMA-IR index) and fasting glucose in both diabetic and non-diabetic individuals.3
Individual study results vary. One trial found 250 mg daily improved insulin resistance and HbA1c in diabetics. Another found no benefit at 360 mg in diabetics who already had normal magnesium levels.
The takeaway: magnesium supplementation likely helps most if you’re deficient.
Related: Foods to avoid with diabetes
Summary: 250 mg or more daily may improve blood sugar control, especially in those with low magnesium levels.
Magnesium for muscle cramps
Magnesium is essential for proper muscle function. Deficiency can contribute to painful cramping.
Research results are mixed. Some studies found 300 mg daily reduced cramp frequency over 6 weeks. Pregnant women taking 300 mg daily reported less frequent and less intense leg cramps.
However, other studies found no significant benefit. The effect may depend on whether you’re actually deficient.
Related: Foods that help with muscle cramps
Summary: 300 mg daily may reduce muscle cramps, though results vary. Worth trying if you experience frequent cramping.
Magnesium for depression
Magnesium deficiency is associated with higher depression risk. Supplementation may help improve mood—particularly in those with low levels.
A meta-analysis of seven clinical trials found magnesium supplementation produced a significant reduction in depression scores.4 Study participants ranged from 20 to 60 years old.
Individual studies have tested various doses:
- 248 mg daily (from magnesium chloride) improved mild-to-moderate depression
- 305 mg daily (from magnesium oxide) for 8 weeks improved depression in those with low magnesium
The benefits appear strongest in people who are actually deficient.
Summary: 248–305 mg daily may improve depression symptoms, especially if you have low magnesium levels.
Magnesium for exercise
Results on magnesium and athletic performance are inconsistent.
One study found 365 mg daily produced no significant changes in performance or muscle gains. Researchers concluded that athletes with adequate magnesium levels probably won’t benefit from supplementation.
Another study found volleyball players taking 350 mg daily showed improved performance compared to controls.
The bottom line: supplementation likely only helps if you’re deficient—and athletes often are, due to increased magnesium loss through sweat.
Summary: 350+ mg daily may boost performance in athletes who are magnesium-deficient. Those with adequate levels likely won’t see benefits.
Magnesium for PMS
Magnesium may help with PMS symptoms like water retention, mood changes, and headaches.
Suggested read: Magnesium Oxide: Benefits, Side Effects, Dosage, and More
Older research found:
- 200 mg daily (magnesium oxide) reduced PMS-related water retention
- 250 mg combined with 40 mg vitamin B6 was more effective than magnesium alone
Summary: 200–250 mg daily may ease PMS symptoms. Combining with vitamin B6 may increase effectiveness.
Magnesium for migraines
People with migraines often have lower magnesium levels, possibly due to genetic absorption issues or stress-related excretion.
Research supports magnesium for migraine prevention:
- A review of five studies found 600 mg daily (magnesium dicitrate) safely reduced migraine frequency
- 500 mg of magnesium oxide was as effective as prescription medication at reducing migraine frequency and duration over 8 weeks
The umbrella review mentioned earlier found strong evidence supporting magnesium supplementation for reducing migraine intensity and frequency.1
Summary: 500–600 mg daily can help prevent migraines. Results are comparable to some prescription medications.
Side effects and safety
The National Academy of Medicine recommends staying below 350 mg from supplements daily for general use. Higher doses should be supervised by a healthcare provider.
Too much magnesium from supplements can cause:
- Diarrhea
- Nausea
- Abdominal cramping
Magnesium toxicity is rare but possible, especially in people with kidney problems.
Drug interactions: Magnesium can interact with antibiotics and diuretics. Check with your doctor if you’re taking medications.
Note: The 350 mg limit applies to supplements, not dietary magnesium. Getting more than this from magnesium-rich foods is safe.
Summary: Keep supplement intake under 350 mg daily unless supervised by a doctor. Side effects are usually digestive.
Bottom line
The right magnesium dose depends on your goals:
| Goal | Suggested daily dose |
|---|---|
| General health | 310–420 mg (from food + supplements) |
| Sleep | 320–500 mg |
| Blood sugar | 250+ mg |
| Muscle cramps | 300 mg |
| Depression | 248–305 mg |
| PMS | 200–250 mg |
| Migraines | 500–600 mg |
For general supplementation, magnesium glycinate or citrate offer good absorption without strong laxative effects. If constipation is your issue, magnesium citrate or hydroxide works better.
Suggested read: CoQ10 Dosage: How Much Should You Take Daily?
Always check with a healthcare provider before taking doses above 350 mg daily, especially if you have kidney issues or take medications.
Related: Magnesium supplements guide
Veronese N, Demurtas J, Pesolillo G, et al. Magnesium and health outcomes: an umbrella review of systematic reviews and meta-analyses of observational and intervention studies. Eur J Nutr. 2020;59(1):263-272. PubMed ↩︎ ↩︎
Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis. BMC Complement Med Ther. 2021;21(1):125. PubMed ↩︎
Simental-Mendía LE, Sahebkar A, Rodríguez-Morán M, Guerrero-Romero F. A systematic review and meta-analysis of randomized controlled trials on the effects of magnesium supplementation on insulin sensitivity and glucose control. Pharmacol Res. 2016;111:272-282. PubMed ↩︎
Moabedi M, Aliakbari M, Erfanian S, Milajerdi A. Magnesium supplementation beneficially affects depression in adults with depressive disorder: a systematic review and meta-analysis of randomized clinical trials. Front Psychiatry. 2023;14:1333261. PubMed ↩︎
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