Medications That Can Lower Your Magnesium Levels

Which medications affect magnesium

A handful of commonly prescribed medications can lower magnesium levels with long-term use, even though they're taken for a completely unrelated reason. This isn't a reason to stop taking a needed medication — it's a reason to be aware, and to mention it to your doctor or pharmacist if you're also experiencing symptoms of low magnesium.

Proton-pump inhibitors (PPIs), used for reflux and heartburn (such as omeprazole and esomeprazole), are the most widely reported cause when taken for extended periods, sometimes a year or more. They're thought to reduce how much magnesium the gut absorbs from food, rather than causing loss directly, which is why the effect tends to build slowly rather than showing up in the first few weeks.

Diuretics, particularly the loop and thiazide types used for blood pressure and fluid retention, increase how much magnesium is lost through urine, alongside other minerals such as potassium. This is a well-established effect and one reason some blood pressure medications are monitored with periodic blood tests.

Other medications linked to lower magnesium include certain antibiotics (the aminoglycoside class), some chemotherapy drugs, and long-term laxative use, which can affect mineral absorption generally. If you take any of these regularly, it doesn't mean you're automatically low — many people take these medications for years without any noticeable effect — but it's a reasonable thing to ask about, especially if you also have symptoms below.

Signs of low magnesium

Muscle cramps or twitches, poor sleep, tension, fatigue and, in more pronounced cases, an irregular heartbeat can all be linked to low magnesium. Some people also notice numbness or tingling in the hands and feet. These signs overlap with many other causes — including low iron, low vitamin D and general stress — so they're a reason to ask your doctor about testing, not a diagnosis on their own.

What to ask your doctor or pharmacist

If you've been on a PPI or diuretic for several months or longer, it's reasonable to ask whether a magnesium check makes sense, particularly if you're also experiencing cramps, fatigue or poor sleep. Your pharmacist can also flag this when dispensing a long-term prescription, so it's worth asking at your next repeat script. Never stop a prescribed medication on your own because you're worried about magnesium — ask about magnesium alongside your existing treatment, not as a replacement for it.

Food sources worth keeping up

Alongside any supplement, leafy greens, nuts, seeds, legumes and wholegrains all contribute dietary magnesium, and keeping these regular in your diet is a sensible baseline whether or not you're on one of the medications above.

Choosing a magnesium supplement

If your doctor confirms low magnesium or you simply want daily support, NutriZen Magnesium Complex combines four forms (oxide, citrate, bisglycinate and malate) for broad support, while Magnesium Oxide is a concentrated single-form option. See our full magnesium guide for how the forms compare. If you take other medication, check timing with your pharmacist, since magnesium can affect the absorption of some antibiotics and osteoporosis medications when taken at the same time — usually resolved by simply spacing the doses a few hours apart.