Magnesium and Muscle Cramps
The most popular claim in the magnesium industry, checked against the Cochrane evidence. What actually helps cramp, from a brand that sells magnesium.
This is the biggest claim in the magnesium industry, and it's the one with the most awkward evidence. We're going to walk you through it properly, and you can decide what to do with that.
WHAT THE COCHRANE REVIEW FOUND
Cochrane reviews pool the available trials and assess how much confidence the evidence supports. The 2020 review on magnesium for skeletal muscle cramps is the most rigorous look at this question available.
For older adults: five studies, 271 participants, average age around 62 to 69. Differences between magnesium and placebo in cramp frequency, intensity and duration were small and not statistically significant. The reviewers' conclusion, at moderate certainty, was that magnesium is unlikely to provide meaningful benefit for cramps in this group.
For pregnancy-related cramps: five studies with important limitations in design and reporting. One found benefit, one found none, one was inconsistent. Results couldn't be pooled. The evidence was rated very uncertain.
For exercise-associated cramps: no studies had evaluated magnesium at all.
Minor side effects from oral magnesium — diarrhoea, nausea — affected roughly 11% to 37% of people taking it.
WE SELL MAGNESIUM AND WE'RE TELLING YOU THIS
Because you'll find it eventually, and it's better you find it here.
If magnesium worked reliably for cramp, the trials would show it. They mostly don't. Anyone promising you cramp relief is selling ahead of the evidence, and we'd rather be the brand you trust on the things we do claim.
WHAT'S STILL TRUE
Magnesium is genuinely involved in muscle relaxation. Calcium drives contraction; magnesium is part of the process that lets a muscle release. The mechanism isn't imaginary.
Genuine magnesium deficiency can cause neuromuscular symptoms including cramping. That's established.
The gap is between "deficiency can cause cramp" and "supplementing helps most people who cramp." Most people who cramp aren't deficient, which is probably why the trials come out the way they do.
WHAT ACTUALLY CAUSES CRAMP
For night cramps, largely unknown, which is unsatisfying and honest. Age, prolonged standing, certain medications and some medical conditions are associated.
For exercise cramps, the leading explanation is neuromuscular fatigue: altered control of contraction in a muscle worked beyond its conditioning, particularly in a shortened position.
WHAT HELPS IN THE MOMENT
Stretching the cramping muscle. For a calf cramp, straighten the leg and pull the toes toward you. This works, immediately, and it's the most reliable intervention there is.
Massage the muscle. Weight-bear and walk it off if you can.
Heat for the residual ache afterwards.
WHAT MAY HELP PREVENT THEM
Regular calf and hamstring stretching, though the evidence here is also mixed.
Reviewing medications with your doctor if cramps started after a new prescription.
Managing training load and conditioning at the ranges where you cramp.
Staying reasonably hydrated, which matters for other reasons regardless.
SEE A DOCTOR IF
Cramps are severe, frequent, or new for you. They're accompanied by weakness, numbness or muscle wasting. They started with a new medication. Or there's swelling, redness and warmth in one calf, which needs urgent assessment for a blood clot rather than treating as cramp.
WHERE OUR PRODUCTS HONESTLY FIT
As comfort measures and as a medium for the things that do work.
Magnesium Gel, 30%: something to massage into a calf that has just seized, and massage is genuinely useful.
Zechstein Bath Soak: a warm bath or foot soak. Heat helps the aftermath.
Pure Magnesium Oil Body Spray: daily use on legs, if you like the routine.
If you use it and your cramps improve, we're glad. We just won't tell you in advance that they will.
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Aria Black products are cosmetic. They aren't intended to diagnose, treat, cure or prevent any disease, including muscle cramps. Sudden calf pain with swelling, redness or warmth needs urgent medical assessment.