Can Magnesium Glycinate 120mg Cause Urinary Frequency?
Magnesium glycinate at 120mg daily does not cause urinary frequency as a direct pharmacological effect. This dose is well below therapeutic levels and represents only about 28% of the recommended daily allowance for magnesium (320mg for women, 420mg for men) 1.
Mechanism and Evidence
Magnesium supplementation, including magnesium glycinate, actually increases urinary magnesium and citrate excretion rather than causing polyuria or increased urinary frequency 2.
The primary urinary effect of magnesium supplementation is increased excretion of magnesium itself and citrate (a stone inhibitor), not increased urine volume or frequency 3, 2.
Organic magnesium salts like magnesium glycinate have superior bioavailability compared to inorganic forms and cause fewer gastrointestinal side effects, making them an excellent choice for supplementation 1, 4.
Common Side Effects vs. Urinary Frequency
The documented side effects of magnesium supplementation are primarily gastrointestinal:
Diarrhea, abdominal distension, and gastrointestinal intolerance are the most common adverse effects, particularly at higher doses 1.
Magnesium glycinate specifically causes less gastrointestinal effects than other forms like magnesium oxide or citrate due to better absorption 4.
Urinary frequency is not listed among the recognized side effects of magnesium supplementation in clinical guidelines 1, 4.
Anxiety Context Considerations
Given the patient's history of anxiety, alternative explanations for urinary frequency should be considered:
Anxiety itself commonly causes urinary frequency through autonomic nervous system activation, independent of magnesium supplementation 5.
Magnesium supplementation has been studied for anxiety treatment, with doses of 125-300mg with each meal (total 375-900mg daily) showing benefit for anxiety symptoms 6.
The 120mg daily dose is subtherapeutic for anxiety treatment and unlikely to cause any significant physiological changes 6, 7.
Clinical Algorithm for Evaluation
If urinary frequency persists, evaluate:
Timing relationship: Did urinary frequency begin precisely when magnesium was started, or is this coincidental? 1
Fluid intake: Has the patient increased water consumption when taking the supplement? 1
Anxiety symptoms: Are anxiety symptoms worsening, which could independently cause urinary frequency? 5, 7
Other medications: Are there concurrent medications (diuretics, caffeine, other supplements) that could explain symptoms? 1
Renal function: Check baseline creatinine clearance to ensure no underlying renal issues, though this dose poses no risk even with mild impairment 1, 4.
Safety Profile at This Dose
120mg of elemental magnesium is extremely safe and well below the Tolerable Upper Intake Level of 350mg/day from supplements 1.
This dose poses no risk of hypermagnesemia even in patients with mild renal impairment (creatinine clearance >30 mL/min) 1, 4.
Magnesium glycinate is better tolerated than other forms and can be taken at night when intestinal transit is slowest for optimal absorption 1, 4.
Recommendation
Continue the magnesium glycinate 120mg as this dose is safe and unlikely to be causing urinary frequency 1, 4. The urinary frequency is most likely related to the patient's underlying anxiety disorder rather than the magnesium supplement 5, 7. If symptoms persist or worsen, evaluate for other causes of urinary frequency including urinary tract infection, diabetes, or worsening anxiety symptoms 1.