Magnesium has been having a moment for a while now. Every sleep account on the internet swears by it. The problem is that not all magnesium is the same, and a lot of cheap supplements use the wrong form, the kind your body cant absorb. We rounded up 5 magnesium supplements that actually use the forms backed by research, all under $30.

Quick crash course before the picks. Magnesium glycinate and magnesium L-threonate are the two forms most studied for sleep. Magnesium oxide, which is what 80% of cheap brands use, is barely absorbed and mostly just gives you a stomach ache. Read the back of the bottle, not the front.

What to Look For When Buying Magnesium for Sleep

Three things matter. First, the form. Glycinate or L-threonate, period. Avoid oxide and citrate if youre buying it for sleep. Second, the dose. Most studies on magnesium and sleep used 200 to 400mg, so anything in that range works. Third, third-party testing. USP Verified, NSF, or ConsumerLab seals mean someone outside the company actually tested the bottle.

Magnesium isnt a sleeping pill. It wont knock you out. What it does, based on the research, is help your nervous system downshift, especially if youre running low on magnesium to begin with (and most Americans are). Give it 2 to 4 weeks before you decide if its working.

For more on sleep supplements that actually have data behind them, check out our 10 sleep aids with real science guide, or browse all Sleep Supplements.