Restless legs syndrome (RLS) affects approximately 5–10% of the UK population, causing uncomfortable sensations and an irresistible urge to move the legs, particularly at night. Many people explore magnesium for restless legs as a potential remedy, given the mineral's role in nerve and muscle function. Whilst magnesium deficiency has been proposed as a contributing factor, robust clinical evidence supporting its use remains limited. NICE guidance does not currently recommend magnesium supplementation for RLS. This article examines the evidence, explores how magnesium might help, and outlines established treatment approaches recommended by UK clinical guidelines.

What Is Restless Legs Syndrome and How Does It Affect You?

Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a neurological condition characterised by an overwhelming urge to move the legs, typically accompanied by uncomfortable sensations. These sensations are often described as crawling, tingling, burning, or aching deep within the leg muscles. The condition predominantly affects the lower limbs, though arms can occasionally be involved.

Symptoms typically worsen during periods of rest or inactivity, particularly in the evening and at night. This circadian pattern can severely disrupt sleep quality, leading to daytime fatigue, reduced concentration, and impaired quality of life. Many patients report that movement—such as walking, stretching, or rubbing the legs—provides temporary relief, though symptoms return once movement stops.

Key features of RLS include:

• An urge to move the legs, usually accompanied by uncomfortable sensations

• Symptoms that begin or worsen during rest

• Partial or complete relief with movement

• Worsening of symptoms in the evening or night

• Symptoms not better explained by another condition (e.g., leg cramps, venous disease, neuropathy)

While RLS symptoms are relatively common, clinically significant RLS affects approximately 5-10% of the UK population. Women appear to experience the condition more frequently than men. The severity ranges from mild, occasional discomfort to debilitating symptoms that significantly impact daily functioning. Primary RLS has no identifiable cause and often runs in families, whilst secondary RLS may be associated with iron deficiency, pregnancy, chronic kidney disease, or certain medications. The exact pathophysiology remains incompletely understood, though dopaminergic dysfunction and iron metabolism abnormalities in the brain are thought to play central roles.

Can Magnesium Help with Restless Legs Syndrome?

Magnesium is an essential mineral involved in over 300 enzymatic reactions in the body, including nerve transmission, muscle contraction, and neurotransmitter regulation. The theoretical basis for magnesium supplementation in RLS stems from its role in modulating neuronal excitability and muscle relaxation. Magnesium deficiency has been proposed as a potential contributing factor in some cases of RLS, though there is no official link definitively established between low magnesium levels and restless legs syndrome.

The current evidence base for magnesium supplementation in RLS remains limited and inconclusive. Small observational studies and case reports have suggested potential benefit in some individuals, particularly those with documented magnesium deficiency. However, large-scale, high-quality randomised controlled trials are lacking. Systematic reviews of complementary therapies for RLS have found insufficient evidence to recommend magnesium as a treatment.

NICE Clinical Knowledge Summaries (CKS) do not currently include magnesium supplementation in RLS treatment recommendations, reflecting the absence of robust clinical evidence. The condition's management focuses primarily on addressing underlying causes (such as iron deficiency), lifestyle modifications, and pharmacological interventions when symptoms are severe.

Important considerations:

• Magnesium supplementation may benefit individuals with documented deficiency

• Response appears highly variable between individuals

• It should not replace evidence-based treatments for moderate to severe RLS

• Any supplementation should be discussed with a healthcare professional

• People with kidney disease should avoid supplementation without medical supervision due to the risk of hypermagnesaemia

Whilst magnesium is generally well-tolerated, it is not a proven treatment for RLS. Patients experiencing persistent or worsening symptoms should seek medical evaluation to exclude secondary causes and discuss appropriate management options.

How to Use Magnesium for Restless Legs: Dosage and Forms

If you and your GP decide that a trial of magnesium supplementation is appropriate, understanding the different forms and dosing considerations is important. Magnesium supplements are available in various formulations, each with different bioavailability and tolerability profiles.

Common magnesium supplement forms include:

• Magnesium citrate – generally well-absorbed and commonly used; may have mild laxative effects

• Magnesium glycinate – often well-tolerated with potentially fewer gastrointestinal side effects

• Magnesium oxide – less well-absorbed but inexpensive; more likely to cause digestive upset

• Magnesium chloride – good absorption; available in oral and topical forms

The Reference Nutrient Intake (RNI) for magnesium in UK adults is 300 mg for men and 270 mg for women. When supplementing, typical doses range from 200–400 mg of elemental magnesium daily, though no standardised protocol exists. It is advisable to start with a lower dose and increase gradually to assess tolerance and response. Taking magnesium with food can reduce gastrointestinal side effects. The UK advice is not to exceed 400 mg per day of elemental magnesium from supplements due to potential side effects.

Some individuals report better results when taking magnesium in the evening, 1–2 hours before bedtime, though evidence for optimal timing is anecdotal. Topical magnesium preparations (oils, creams, bath salts) are marketed for RLS, but there is limited evidence regarding transdermal absorption and clinical efficacy.

Important safety considerations:

• Excessive magnesium intake can cause diarrhoea, nausea, and abdominal cramping

• Individuals with kidney disease should avoid supplementation without medical supervision

• Magnesium can interact with several medications, including:

• Antibiotics (quinolones, tetracyclines)
• Bisphosphonates
• Levothyroxine

• Diuretics

• Separate magnesium supplements from interacting medicines by 2–4 hours

• Always inform your GP or pharmacist about all supplements you are taking

Routine testing of magnesium levels is not generally necessary unless there is clinical suspicion of deficiency. It's worth noting that serum magnesium measurements may be normal despite tissue deficiency.

Other Treatment Options for Restless Legs Syndrome

NICE recommends a stepwise approach to managing RLS, beginning with identification and correction of underlying causes and lifestyle modifications before considering pharmacological interventions.

Initial assessment and management: Your GP should check serum ferritin levels, as iron deficiency is a common and treatable cause of RLS. If ferritin is below 75 micrograms/L, oral iron supplementation is recommended, with a target often above 75-100 micrograms/L. Other blood tests may include full blood count, renal function, and glucose to exclude secondary causes. A medication review is essential, as certain drugs can exacerbate RLS symptoms, including some antidepressants (particularly mirtazapine, SSRIs), antipsychotics, sedating antihistamines, and anti-emetics (metoclopramide, prochlorperazine).

Lifestyle and non-pharmacological measures:

• Establishing good sleep hygiene practices

• Regular moderate exercise (avoiding intense exercise close to bedtime)

• Reducing caffeine, alcohol, and nicotine intake

• Leg massage, hot baths, or cold compresses

• Mental alerting activities during periods of inactivity

• Maintaining a regular sleep-wake schedule

Pharmacological treatments: For moderate to severe RLS that significantly impacts quality of life and has not responded to conservative measures, NICE recommends non-ergot dopamine agonists (pramipexole, ropinirole, or rotigotine transdermal patch) as first-line pharmacological therapy. Alpha-2-delta ligands (gabapentin or pregabalin) may be considered in specific cases, such as when pain or insomnia are prominent features, or if dopamine agonists are not tolerated.

Important risks to consider include:

• Dopamine agonists: augmentation (worsening of symptoms with long-term use), impulse control disorders (gambling, hypersexuality, compulsive shopping)

• Gabapentin/pregabalin: sedation, dizziness, and potential for dependence (both are Schedule 3 controlled drugs)

• Driving may be affected by these medications, particularly when starting treatment

Special considerations: In pregnancy, non-pharmacological approaches and iron supplementation are preferred. Specialist advice should be sought if symptoms are severe.

When to seek medical advice:

• Symptoms significantly affect sleep or daily functioning

• Symptoms occur more than twice weekly

• Conservative measures have been ineffective

• You experience daytime sleepiness affecting safety (e.g., driving)

• Symptoms suddenly worsen or change in character

Referral to a specialist sleep clinic or neurologist may be appropriate for complex cases, diagnostic uncertainty, or inadequate response to initial treatments. If you experience side effects from any medication, report them to the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk).

Frequently Asked Questions