Creatine and Magnesium Glycinate: Can You Take Both?

Yes. There is no known interaction between creatine and magnesium glycinate, and they do different jobs, so taking them at different times of day is fine. Creatine is for muscle and strength with training. Magnesium glycinate is usually taken in the evening to fill a dietary gap or for sleep. The idea that magnesium makes creatine work better comes from a handful of small trials on a special bonded form called magnesium creatine chelate, and the best controlled of them found no advantage over plain creatine.

Evidence grade

• Creatine improves strength and muscle with training. Grade: Strong. Why: Many RCTs and meta-analyses (ISSN position stand, 2017).
• Magnesium improves physical performance when intake is low. Grade: Limited. Why: One RCT in older women (Veronese 2014).
• Magnesium creatine chelate beats plain creatine. Grade: Limited. Why: Small trials, the best controlled one found no difference.
• Magnesium prevents muscle cramps. Grade: Not supported for typical night cramps. Why: Cochrane review, moderate to high certainty of no meaningful benefit.
• Magnesium helps sleep. Grade: Limited. Why: 3 small trials, low quality evidence.

Key takeaways

• Your muscle cells use ATP bound to magnesium, and creatine kinase (the enzyme that recycles ATP from creatine) needs it too. That is the logic for pairing them, but no trial shows that adding magnesium boosts plain creatine.
• In Selsby's 2004 trial, magnesium creatine chelate and plain creatine (both 2.5 g a day) improved bench press work equally.
• Cochrane found magnesium does not meaningfully reduce typical night time leg cramps. Creatine users in one season of college football had fewer cramps, not more.
• Supplemental magnesium has an upper limit of 350 mg a day for adults (NIH). Count all your supplements, including any magnesium in a creatine blend.

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Why the pairing makes sense on paper

Almost all the ATP in your cells is bound to magnesium, and creatine's job is to rebuild ATP quickly during hard efforts. So if you were low in magnesium, in theory your muscles would get less out of creatine. That theory is reasonable. What is missing is a trial showing that people with normal magnesium status get more from creatine when they add magnesium.

Low intake is common, though. The NIH Office of Dietary Supplements notes that many people in the US eat less than the recommended 310 to 420 mg a day, with men over 70 and teenagers most likely to fall short. If that describes your diet, magnesium is worth fixing for its own sake.

The magnesium creatine chelate trials

• Brilla 2003, Metabolism. Who: 35 adults, 2 weeks. What they took: Placebo, magnesium oxide plus creatine, or magnesium creatine chelate (800 mg magnesium and 5 g creatine a day). Result: Only the chelate group raised water inside cells and knee extension peak torque significantly.
• Selsby 2004, J Strength Cond Res. Who: 31 weight trained men, 10 days. What they took: Placebo, creatine 2.5 g a day, or chelate with 2.5 g creatine. Result: Both creatine groups did more bench press work than placebo; chelate and plain creatine performed the same.
• Zajac 2020, Nutrients. Who: 20 elite soccer players, 16 finished, 16 weeks. What they took: Magnesium creatine chelate (0.07 g per kg a day) or placebo. Result: Sprint times improved in the chelate group and not with placebo; no plain creatine group for comparison.

Two cautions. Brilla's 800 mg of magnesium a day is more than double the upper limit for supplements, so it is not a dose to copy. And with 16 finishers and no plain creatine arm, Zajac's trial cannot tell you whether the chelate does anything monohydrate would not.

Our read is that plain creatine monohydrate plus a separate magnesium supplement, if you need one, covers everything the chelate offers and lets you dose each properly.

Cramps

A common worry is that creatine causes cramps and magnesium prevents them. The evidence points the other way on both.

• Creatine. In one season of Division I college football, the 38 players who chose to take creatine had fewer reports of cramping, muscle tightness and strains than the 34 who did not (Greenwood 2003). Players chose for themselves, so this is not proof creatine prevents cramps, but it is evidence against creatine causing them.
• Magnesium. A 2020 Cochrane review of 11 trials found that for typical night leg cramps, mostly in adults in their 60s, magnesium made no meaningful difference to how often cramps happened. Cramps linked to pregnancy may be different, but those trials were at high risk of bias.

For night cramps, magnesium is unlikely to help. No trial in the Cochrane review tested it for cramps during exercise.

Where magnesium may help

Performance. Veronese and colleagues (2014) gave 300 mg of magnesium a day, as magnesium oxide, for 12 weeks to healthy older women already doing a weekly exercise class. They improved on a standard physical performance score, chair stand times and walking speed compared with women given nothing extra, and the gains were clearest in women whose diets were low in magnesium. The control group got no placebo, which weakens the result.

Sleep. A 2021 meta-analysis pooled 3 small trials in older adults with insomnia. Magnesium shortened the time to fall asleep by about 17 minutes compared with placebo, and the authors rated the evidence as low to very low quality.

Glycinate is often sold as gentler on the stomach than oxide or citrate, but we could not find trials that compare forms head to head for performance or sleep. Our magnesium forms guide compares glycinate, threonate and malate in more detail.

How to take them together

• Typical dose. Creatine monohydrate: 3 to 5 g a day. Magnesium glycinate: Enough to close your dietary gap, keeping supplements at or under 350 mg elemental magnesium a day.
• Timing. Creatine monohydrate: Any time; consistency matters most. Magnesium glycinate: Often taken in the evening.
• Same time is fine? Creatine monohydrate: Yes, nothing suggests they interfere. Magnesium glycinate: Yes.
• Label tip. Magnesium glycinate: The big number on many glycinate labels is the whole compound; look for "elemental magnesium".

Our magnesium dose calculator helps estimate your gap from food.

Safety

• Kidneys. Creatine raises blood creatinine slightly, which can make a kidney function estimate (eGFR) look lower without harm. Magnesium is cleared by the kidneys, so people with kidney disease should not supplement it without medical advice. If you have kidney disease, talk to your doctor before taking either.
• Medicines. Magnesium can reduce absorption of some antibiotics and osteoporosis drugs (bisphosphonates) if taken too close together, according to NIH. Space them apart and ask your pharmacist.
• Too much magnesium. Above the 350 mg supplement limit, diarrhea, nausea and abdominal cramping become more likely.

For everything else about creatine, see the creatine guide. For the broader case for magnesium, see magnesium supplementation.

This page is general information, not medical advice.

Sources

1. Brilla LR, Giroux MS, Taylor A, Knutzen KM. Magnesium-creatine supplementation effects on body water. Metabolism. 2003;52(9):1136-1140. PMID 14506619

2. Selsby JT, DiSilvestro RA, Devor ST. Mg2+-creatine chelate and a low-dose creatine supplementation regimen improve exercise performance. J Strength Cond Res. 2004;18(2):311-315. PMID 15142029

3. Zajac A, Golas A, Chycki J, Halz M, Michalczyk MM. The effects of long-term magnesium creatine chelate supplementation on repeated sprint ability (RAST) in elite soccer players. Nutrients. 2020;12(10):2961. PMID 32998206

4. Greenwood M, Kreider RB, Greenwood L, Byars A. Cramping and injury incidence in collegiate football players are reduced by creatine supplementation. J Athl Train. 2003;38(3):216-219. PMID 14608430

5. Garrison SR, Korownyk CS, Kolber MR, et al. Magnesium for skeletal muscle cramps. Cochrane Database Syst Rev. 2020;9(9):CD009402. PMID 32956536

6. Veronese N, Berton L, Carraro S, et al. Effect of oral magnesium supplementation on physical performance in healthy elderly women involved in a weekly exercise program: a randomized controlled trial. Am J Clin Nutr. 2014;100(3):974-981. PMID 25008857

7. Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a systematic review and meta-analysis. BMC Complement Med Ther. 2021;21(1):125. PMID 33865376

8. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18. PMID 28615996

9. NIH Office of Dietary Supplements. Magnesium fact sheet for consumers. ods.od.nih.gov