Magnesium Citrate 400 mg by NOW

If you get muscle cramps, restless legs, or struggle with regularity, magnesium citrate 400 mg is a practical starting point. It suits people whose Serum Magnesium or RBC Magnesium (a red‑blood‑cell measure of tissue magnesium) is low or low‑normal, endurance athletes with heavy sweat loss, and high‑stress sleepers who grind or twitch at night. It’s also useful if you take proton‑pump inhibitors for reflux, which can lower magnesium over time. If constipation is your main issue, this form’s gentle loosening effect is often a plus.

Magnesium is the mineral that turns ATP (the cell’s energy currency) into its usable form, so low levels feel like low energy. In muscle and nerve cells, it tempers calcium entry, which helps muscles relax after they contract and steadies nerve firing. Magnesium citrate is an organic salt that’s better absorbed than oxide, yet it draws water into the gut, which explains the common soft‑stool effect. In the brain it quiets NMDA receptors (excitatory signal ports), a likely reason some people sleep more soundly once replete.

Take the NOW magnesium citrate as directed: three capsules daily, preferably split with meals to improve absorption and reduce loose stools. Evening dosing can help with muscle relaxation and sleep, while morning or midday helps if regularity is the goal. Recheck Serum Magnesium or RBC Magnesium after 4 to 8 weeks. If you’ve had documented deficiency, you may need a higher short‑term intake under clinician guidance, then step down to this maintenance level.

Skip magnesium citrate or get clearance if you have advanced kidney disease, since impaired clearance can raise blood magnesium. Separate it by 2–4 hours from levothyroxine, iron supplements, and antibiotics like doxycycline or ciprofloxacin, because magnesium binds these and blocks absorption. Thiazide or loop diuretics increase losses, so needs can be higher, while potassium‑sparing diuretics usually don’t. If stools become persistently loose, reduce the dose or consider magnesium glycinate, which is gentler on the gut.