Magnesium and Fertility
Current evidence does not support routine magnesium supplementation for improving fertility outcomes in either men or women, as high-quality studies show no significant benefit on pregnancy rates or sperm parameters.
Evidence from Male Infertility Guidelines
The most authoritative guidelines on male infertility do not recommend magnesium supplementation as an evidence-based treatment:
Major international guidelines (WHO, AUA/ASRM, EAU) consistently state there are insufficient data to recommend supplemental antioxidant or mineral therapies, including magnesium, for treating male infertility 1.
The 2017 WHO guidance analysis concluded that "there are insufficient data to recommend the use of supplemental antioxidant therapies for the treatment of men with abnormal semen parameters and/or male infertility" with a low strength of evidence 1.
The 2025 European Association of Urology guidelines note that while oxidative stress may contribute to infertility, evidence for antioxidant therapy remains conflicting, and when high-risk-of-bias studies are removed from meta-analyses, benefits on live birth rates disappear 1.
Direct Research on Magnesium Supplementation
The limited studies specifically examining magnesium show no clinical benefit:
A randomized, placebo-controlled trial of magnesium-orotate (3000 mg/day for 90 days) in idiopathic male infertility found no significant improvement in sperm concentration, motility, morphology, or pregnancy rates compared to placebo 2. While ejaculate ionized magnesium increased, this did not translate to fertility improvements.
In women undergoing assisted reproduction, total serum magnesium levels do not appear altered in infertile versus fertile women, and levels remain stable during ovarian stimulation despite rising estrogen 3.
Limited Exception: Combined Magnesium-Selenium Deficiency
One small study suggests a potential role only in specific deficiency states:
- Six women with documented red blood cell magnesium deficiency that failed to normalize with magnesium alone achieved normalization when selenium was added, and all subsequently conceived 4. However, this represents a highly selected population with documented deficiency and cannot be generalized to routine supplementation.
Dietary Magnesium May Modify Other Risk Factors
- Recent population data suggests high dietary magnesium intake (≥243 mg/day) may ameliorate the association between elevated serum uric acid and female infertility, though this does not establish causation 5.
What Guidelines Actually Recommend Instead
Rather than mineral supplementation, evidence-based fertility guidelines emphasize:
Lifestyle modifications including weight loss, physical exercise, and smoking cessation, which have demonstrated benefits on sperm parameters and overall health 1.
Evaluation and treatment of identifiable causes of infertility rather than empiric supplementation 1.
CoQ10 supplementation shows more promise than magnesium for oocyte quality in women, particularly those over 35 or undergoing ART 6.
Clinical Bottom Line
Do not recommend routine magnesium supplementation for fertility enhancement. Focus instead on evidence-based interventions: identifying and treating specific causes of infertility, optimizing lifestyle factors (weight, exercise, smoking cessation), and considering CoQ10 for women with documented indications 1, 6. If magnesium supplementation is considered, it should only be in documented deficiency states with concurrent selenium evaluation, not as empiric therapy 4.