Magnesium for Menstrual Cramps: Evidence-Based Evaluation
Magnesium supplementation is effective for relieving menstrual cramps (dysmenorrhea), particularly when administered at doses of 200-400 mg daily starting before menstruation begins. 1
Mechanism of Action
Magnesium works to alleviate menstrual cramps through several mechanisms:
- Acts as a muscle relaxant, reducing uterine contractions
- Has anti-inflammatory and antioxidant properties
- Improves microvascular circulation in the uterus
- Regulates the movement of other electrolytes (sodium, potassium, calcium) across cell membranes 2
Evidence for Effectiveness
The evidence supporting magnesium for menstrual cramps comes from several studies:
- A systematic review found that magnesium supplementation is effective in preventing dysmenorrhea 1
- A randomized double-blind study showed that magnesium (3 × 5 mmol granulate) reduced back pain and lower abdominal pain on the second and third day of menstruation 3
- Magnesium supplementation led to reduced absences from work due to dysmenorrhea 3
- Another study demonstrated that 200 mg of magnesium oxide daily for two menstrual cycles significantly reduced symptoms of fluid retention associated with menstruation (weight gain, swelling, breast tenderness, abdominal bloating) 4
Recommended Protocol
For optimal results in treating menstrual cramps:
- Dosage: 200-400 mg of magnesium daily
- Timing: Begin supplementation 1-4 days before expected menstruation and continue through the first 2-3 days of menstruation
- Form: Organic magnesium salts (aspartate, citrate, lactate) have superior bioavailability compared to magnesium oxide 2
- Administration: Divide doses throughout the day to improve tolerance and absorption
Important Considerations
Potential Side Effects
- Diarrhea (most common dose-limiting side effect)
- Abdominal cramping
- Nausea 2
If these occur, reduce the dose and gradually increase as tolerated.
Contraindications
- Renal impairment (risk of hypermagnesemia)
- Overt renal failure is an absolute contraindication 2
Dietary Sources
Increasing dietary magnesium may also help prevent menstrual cramps. Good sources include:
- Whole grains
- Nuts and seeds
- Leafy green vegetables
- Legumes
- Coffee and tea 2
Monitoring
- Target serum magnesium level: >0.6 mmol/L (>1.5 mg/dL)
- Normal plasma magnesium range: 1.5 to 2.5 mEq/L
- Levels below 1.3 mEq/L are considered deficient 2
Conclusion
Magnesium supplementation represents a viable, evidence-based treatment option for women suffering from menstrual cramps. The evidence suggests that starting supplementation before menstruation begins and continuing through the first few days of the cycle provides the most benefit. Organic magnesium forms are preferred due to their superior bioavailability, and doses should be divided throughout the day to minimize gastrointestinal side effects.