For most healthy adults, the typical total daily magnesium target (from food plus supplements) is about 310–320 mg per day for women and 400–420 mg per day for men.

Quick Scoop

You usually don’t need huge doses. The goal is to meet the daily requirement , not megadose, unless a doctor specifically tells you to.

General daily targets

  • Adult men: about 400–420 mg per day.
  • Adult women (not pregnant): about 310–320 mg per day.
  • Pregnant women: around 350–360 mg per day.
  • Most of this should ideally come from food (nuts, seeds, whole grains, beans, leafy greens).

How much from supplements?

Because you’re already getting some magnesium from food, many guidelines suggest not exceeding 350 mg per day from supplements alone for adults and kids over 9.

  • If your diet is decent, many people take around 100–200 mg/day in supplement form to “top up,” but this should be individualized.
  • Going much above the total daily recommended range (e.g., 500+ mg/day long term) can cause diarrhea, stomach upset, and, in extreme cases or with kidney problems, magnesium toxicity.

When you might need a different dose

Magnesium dosing can change depending on why you’re taking it:

  • For constipation, some forms (like magnesium citrate or hydroxide) are used at higher, laxative doses for short periods, usually under medical or product-label guidance.
  • For sleep, cramps, or migraines, many people use 100–300 mg in the evening, but studies use varying amounts and forms; a professional can tailor this.

Safety rules of thumb

  • Don’t exceed about 350 mg/day from supplements unless your doctor specifically tells you to.
  • Be extra cautious if you have kidney disease , heart rhythm issues, or take medications like certain diuretics, proton‑pump inhibitors, or antibiotics—magnesium can interact with these.
  • If you notice persistent diarrhea, nausea, or cramping, your dose is likely too high or the form doesn’t agree with you.

Simple example

If you’re an adult woman eating a fairly normal diet and want a safe starting point:

  • Aim for food sources first (e.g., a handful of almonds, some beans, whole grains, and leafy greens daily).
  • Consider a 100–200 mg magnesium supplement once daily, making sure your total doesn’t regularly exceed about 310–320 mg/day from all sources by too much.

But the best dose for you depends on your age, sex, diet, medical conditions, and meds, so it’s wise to check with a healthcare professional before starting or increasing magnesium supplements, especially if you’re thinking about higher doses.

TL;DR:
Most adults need roughly 310–320 mg/day (women) or 400–420 mg/day (men) of magnesium in total, and you generally shouldn’t take more than 350 mg/day from supplements unless a doctor advises otherwise.

Information gathered from public forums or data available on the internet and portrayed here.