Magnesium – What’s the Right Amount? by Dr. Georgia Tetlow, M.D.


Magnesium is one of the most important molecules in the body, secondary to only potassium. It is involved in over 300 biochemical reactions, including activation of enzymes, relaxation of smooth muscle (gastrointestinal), skeletal muscle and is key in membrane transport, energy metabolism of carbohydrates, fats and proteins, as well as calcium and phosphorus metabolism.

If you are low, you may have tight muscles, constipation, difficulty sleeping or anxiety. Or all of these! Deficiency can also cause cardiac arrhythmias, vertigo, seizures, bone loss, depressed immunity, fatigue, hypertension, poor wound healing…also slow transit time in the gastrointestinal tract leads to hyper-absorption of hormones like estrogen, which can increase your risk of estrogen sensitive cancers (breast and uterine) as well as estrogen symptoms during menstruation or perimenopause.

How to Take Magnesium Glycinate

Magnesium is an excellent mineral for improving transit time through the gastrointestinal tract. That means if you take too much, you have loose stools. Thankfully, these will stop after you reduce your magnesium. It takes weeks to months for your body to replete itself of this mineral, so I recommend magnesium glycinate, the most bioavailable form. I do not recommend taking magnesium citrate, oxide or other forms as these tend to cause loose stools and stomach upset at low doses.

  1. Take approximately 300mg the first night (if each capsule is 100mg, you will be taking 3). Nighttime is a good time for absorption and magnesium can improve the quality of your sleep.
  2. Continue nightly doses based on the looseness of your stools—let me explain. You will be changing your dose of magnesium based on your body’s response. Aim for 1-2 bowel movements daily. If you are going more frequently, then reduce your dose…if you overdo magnesium, you may need to stop for a day or two.
  3. If you have been constipated recently and you have no bowel movement the day following your first dose, increase your dose by 100mg (1 capsule) and stay there for a few nights to see what happens. If you have not moved your bowels, keep on increasing by 100mg every few days. Eventually note the right amount you need each night for your body—this could be 1, but will more likely be several capsules. Some individuals need a lot of magnesium, especially if you are on diuretics. Do not exceed more than 1500mg daily (don’t worry, you won’t).

For reputable sources of magnesium glycinate, try Klaire brand for 100mg caps or Design for Health Chelated Buffered Magnesium (glycinate) for 150mg caps at