Minerals
Magnesium Glycinate — timing, dose & interactions
Magnesium bound to the amino acid glycine. Popular for sleep and generally well tolerated, with less laxative effect than citrate or oxide. Trials of this specific form are scarce — the sleep reputation is extrapolated from magnesium and glycine separately.
Also known as: Magnesium bisglycinate
Timing
When to take it
Usually taken in the evening or at bedtime; it's gentle on the stomach, so food is optional.
Dose note. UL applies to all supplemental magnesium combined (not food); mainly to prevent diarrhea.
Interactions
Magnesium Glycinate with other supplements
Magnesium Glycinate + Calcium
Very high calcium may reduce magnesium absorption
Magnesium Glycinate + Zinc
Very high zinc can reduce magnesium absorption
Magnesium Glycinate + Vitamin D3
Magnesium is required to activate vitamin D
Magnesium Glycinate + Psyllium Husk
Fiber can reduce magnesium absorption
Magnesium Glycinate + Potassium
Low magnesium makes low potassium hard to fix
Magnesium Glycinate + Magnesium
Two forms of magnesium
Magnesium Glycinate + Magnesium Citrate
Two forms of magnesium
Magnesium Glycinate + Magnesium L-Threonate
Two forms of magnesium
Magnesium Glycinate + Magnesium Malate
Two forms of magnesium
Magnesium Glycinate + Magnesium Oxide
Two forms of magnesium
Safety
Medications & health conditions
Magnesium reduces levothyroxine absorption. Magnesium binds levothyroxine in the gut and can lower thyroid hormone levels. Keep it at least 4 hours away from your thyroid medication.
Magnesium blocks absorption of these antibiotics. Magnesium binds tetracycline and quinolone antibiotics in the gut, which can make the antibiotic less effective. Typically take the antibiotic at least 2 hours before or 4–6 hours after magnesium — the exact spacing depends on the drug, so follow its label.
Magnesium can build up with kidney disease. The kidneys remove excess magnesium. With reduced kidney function, supplements can cause dangerous hypermagnesemia.
PPIs can lower magnesium. Long-term PPI use is linked to low blood magnesium. That's a reason to have your level checked, not a reason to avoid magnesium.
Magnesium blocks HIV integrase inhibitors. The labels advise taking dolutegravir or bictegravir 2 hours before or 6 hours after products containing magnesium.
Buying guide
What to look for on the label
Magnesium Glycinate
- Check elemental magnesium per serving — glycinate is only about 14% magnesium by weight
- Fully reacted (buffered products may contain oxide)
FAQ
Common questions
When is the best time to take Magnesium Glycinate?
Bedtime. Usually taken in the evening or at bedtime; it's gentle on the stomach, so food is optional.
Should Magnesium Glycinate be taken with food?
It can be taken with or without food. Usually taken in the evening or at bedtime; it's gentle on the stomach, so food is optional.
Can you take Magnesium Glycinate with Calcium?
Yes, at normal doses. At high calcium doses, spacing them out is a reasonable precaution. No action needed at typical doses. If you take ≥1,000 mg calcium from supplements, take magnesium at a different time (e.g. bedtime).
Can you take Magnesium Glycinate with Zinc?
Yes — this only matters at very high zinc doses. Keep zinc within the 40 mg/day upper limit.
Can you take Magnesium Glycinate with Vitamin D3?
Yes — adequate magnesium helps vitamin D work, especially at higher D doses. Make sure magnesium intake is adequate if you take vitamin D, especially at higher doses. They do not need to be taken at the same time.
Can you take Magnesium Glycinate with Psyllium Husk?
Separate them by about 2 hours. Take psyllium at least 2 hours apart from magnesium.
Sources