Magnesium Supplements: Types, Benefits, Evidence (limited), and Considerations for Midlife & Older Women

Magnesium is an essential mineral involved in over 300 enzymatic reactions, including muscle function, nerve signaling, bone health, sleep regulation, and blood-glucose control. Many adults — especially women in midlife and older adulthood — may not consume enough magnesium through diet alone.

This article reviews the most common forms of magnesium supplements, what they’re best for based on scientific evidence, and important safety considerations.

Why magnesium matters — especially for midlife women

Magnesium needs change across the lifespan. Women aged 31+ need about 320 mg/day from food and supplements combined.

Research suggests magnesium may be particularly relevant during perimenopause and postmenopause, when women experience:

• Sleep disturbances

• Increased bone loss

• Mood and stress changes

• Muscle tension

Magnesium plays a role in bone metabolism and sleep regulation, both of which are commonly affected during menopause.

Higher magnesium intake in older adults has also been associated with:

• Lower risk of kidney function decline

• Reduced odds of chronic kidney disease and kidney stones, especially in women .

(These findings are largely observational but consistent across multiple studies.)

Types of magnesium supplements (and what they may be good for)

Magnesium glycinate (bisglycinate)

Best for: sleep, anxiety, muscle tension, people prone to digestive side effects.

Magnesium glycinate is magnesium bound to the amino acid glycine. It is generally well-absorbed and less likely to cause diarrhea than some other forms.

Evidence suggests magnesium supplementation may:

• Improve sleep quality in older adults

• Support circadian rhythm regulation

Some clinical and observational studies show magnesium may support relaxation and neuromuscular function, particularly in people with low magnesium intake.

Magnesium citrate

Best for: constipation relief, general supplementation

Magnesium citrate is highly bioavailable and commonly used as a gentle osmotic laxative.

Because it draws water into the intestines, it can cause:

Loose stools

Abdominal cramping

This effect makes it useful for people with constipation, but less ideal for daily high-dose supplementation.

Magnesium oxide

Best for: short-term deficiency correction or laxative use

Magnesium oxide contains a high percentage of elemental magnesium but is poorly absorbed compared with other forms.

It is more likely to cause:

Diarrhea

GI discomfort

For long-term supplementation, other forms are usually preferred.

Magnesium L-threonate

Best for: cognitive health (emerging research)

Magnesium L-threonate is being studied for brain health and memory, particularly in older adults.

Preliminary research suggests it may:

• Improve memory and cognition

• Support neurological function

However, evidence is still limited and larger trials are needed.

Magnesium malate

Best for: fatigue and muscle pain (limited evidence)

Magnesium malate combines magnesium with malic acid, which is involved in cellular energy production. Some clinicians use it for:

• Chronic fatigue

• Fibromyalgia-related pain

Evidence is still emerging, and most support is clinical or small-study-based.

Magnesium chloride

Best for: general supplementation and deficiency correction

Magnesium chloride is well absorbed and often used in:

Oral supplements

Topical magnesium products

It may be helpful for restoring magnesium levels in people with deficiency.

Magnesium and bone health in older women

Magnesium contributes to bone mineral density and calcium metabolism.

Some observational evidence suggests higher magnesium intake is associated with:

Better bone density

Reduced osteoporosis risk

However, magnesium should be considered supportive, not a replacement for:

• Calcium

• Vitamin D

• Osteoporosis medications when needed

Magnesium and heart rhythm

Magnesium is essential for electrical signaling in heart muscle cells. Low magnesium levels (hypomagnesemia) are known to increase risk of certain rhythm problems.

Clinical research shows magnesium can help in specific situations, for example:

• Preventing arrhythmias after cardiac surgery

• Treating torsades de pointes (a specific dangerous arrhythmia)

• Supporting normal potassium balance, which affects heart rhythm

Example research:

Gu et al., Clinical Cardiology (2012): magnesium reduced postoperative arrhythmias

https://pubmed.ncbi.nlm.nih.gov/22492140/

EFSA magnesium review:

https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2015.4186

So magnesium itself is not harmful to the heart when levels are normal — in fact, deficiency can increase arrhythmia risk.

However, it should be discussed with a healthcare professional if someone has:

• Known heart rhythm disorders

• Structural heart disease

• Kidney disease

• Multiple medications

This is especially relevant in midlife and older adults, when kidney function and medication use often change.

Safety and cautions with magnesium supplementation

Magnesium is generally safe, but supplementation requires care.

Upper intake levels

The tolerable upper intake level for supplemental magnesium is about:

350 mg/day from supplements (not including food sources)

Higher doses are sometimes used medically, but should be supervised.

Common side effects

Possible side effects include:

Diarrhea

Nausea

Abdominal cramping

These occur more often with:

Magnesium oxide

Magnesium citrate

Magnesium toxicity (rare but serious)

Excessive magnesium intake can cause:

• Low blood pressure

• Muscle weakness

• Confusion

• Irregular heartbeat

  
  

Risk is highest in people with kidney disease, because magnesium is cleared through the kidneys.

Kidney function and aging

This is especially important for older adults.

Because kidney function naturally declines with age:

Magnesium supplementation may require monitoring

High doses should be avoided if kidney function is impaired

Medication interactions

Magnesium supplements can interact with:

• Antibiotics

• Diuretics

• Digoxin

• Diabetes medications

• Proton-pump inhibitors e.g. omeprazole, esomeprazole (indirectly affecting magnesium levels)

Spacing doses by several hours is often recommended.

Practical guidance for midlife and older women

Magnesium supplementation may be worth discussing with a clinician if you experience:

• Sleep difficulties during menopause

• Muscle cramps or tension

• Constipation

• Low dietary intake

• Osteopenia or osteoporosis risk

Many clinicians start with:

100–200 mg/day elemental magnesium

(Usually glycinate or citrate)

Dietary sources should remain the foundation:

• Leafy greens e.g. spinach, Swiss chard

• Nuts, e.g. almonds

• Seeds, e.g. pumpkin seeds

• Black beans

• Whole grains

Key takeaway

Magnesium supplements can support sleep, muscle relaxation, bowel regularity, and possibly bone and kidney health, particularly for midlife and older women.

The form of magnesium matters, and supplementation should be individualized based on:

• Symptoms

• Kidney function

• Medications

• Diet

For most people, moderate supplementation combined with magnesium-rich foods is safe and effective.