Research into Magnesium and RLS/PLMS

I know that the use of Magnesium to control/treat RLS is considered at best unproven and at worst controversial, but I - and various others - have found dosing with Magnesium Citrate very helpful.

The studies looking into this have been much too small, and peer reviews have deemed studies inconclusive, but I thought it might be helpful to summarise what I've read here:

In 2017 Schwalfenberg and Genuis wrote about the importance of magnesium in clinical healthcare, and the noted deficiency in Western diets, reporting in part "Magnesium, sleep, and Restless Leg Syndrome: It is estimated that 50% of older adults have insomnia. Magnesium is a natural NMDA antagonist and a GABA agonist, both biochemical actions which have a relaxant effect and facilitate sleep. Supplementation of 500 mg of Mg has been associated with significant improvement in the insomnia severity index, sleep time, sleep efficiency, sleep onset latency, serum cortisol concentration, serum renin, and melatonin"

ncbi.nlm.nih.gov/pmc/articl...

I have seen references to a Romanian Journal of Neurology report, which I've not been able to trace as yet, where "researchers conducted biochemical and neurological tests in 10 cases of restless leg syndrome. The investigators reported important disorders of sleep organization. They found agitated sleep with frequent periods of nocturnal awakenings and a decrease of the duration and percentage of the deeper rapid eye movement (REM) sleep; also found in other forms of insomnia caused by magnesium deficiency."

The tiny Hornyak et al study in 1998 is widely quoted, showing a positive response to magnesium in both PLMS and RLS, as reported in Sleep:

academic.oup.com/sleep/arti...

It concluded that "Further investigations regarding the role of magnesium in the pathophysiology of RLS and placebo-controlled studies need to be performed", but there is little evidence that this has really been followed up properly.

Marshall et al attempted to review the literature in 2019:

sciencedirect.com/science/a...

concluding "It is not clear whether magnesium helps relieve RLS or PLMD or in which patient groups any benefit might be seen"

The tiny Illinois trial announced in 2020 (which was to be of 15 people, still far too small) is due to report back in the Spring. Frankly, it is again too small, and the proposed dose is too small to be conclusive:

clinicaltrials.gov/ct2/show...

I really hope that there is or will be a really large scale peer reviewed study into magnesium and RLS, but can only reiterate that I and others that I know have definitely found it useful!

[Amrob]

Thanks for this Andy. It's sometimes useful to revisit particular therapies. I haven't come across these papers before. Interestingly, in pregnancy I took a high dose of Magnesium ( without any prescription meds) and my PLMs seemed to be under a degree of control. It's hard to separate that particular regime from other changes happening in my body but given that pregnancy usually worsens RLS and possibly PLMD, that wasn't my experience.

[Madlegs1]

Thanks for the information.

I think many people here have found magnesium very helpful, despite that it hasn't very much research backing.

Even the latest RLS American magazine ,which has some excellent articles, doesn't rate magnesium very highly.

I use it regularly and definitely miss it when I forget to take it. And that is only 100mg of citrate!🙄

[AnotherRLScase]

I used magnesium malate alternating with magnesium oil or lotion with good success for a few years, but eventually experienced augmentation with it. Didn't realize what was happening, so I had started taking more and more, until it was affecting heart rhythms. Stopped immediately after that. On the plus side, no withdrawal symptoms. When it worked, it worked really well.

Now I'm taking ropinirole (.5mg) nightly along with iron on alternating days and a THC gummy (legal where I live). Right now, the iron seems to be having the best effect.