From the Guidelines
The recommended dose of magnesium citrate for adults is typically 250-500 mg taken once daily, as suggested by the most recent and highest quality study 1. When considering the use of magnesium citrate, it's essential to prioritize the single most recent and highest quality study, which in this case is from 2023 1. This study provides guidance on the management of chronic idiopathic constipation, including the use of magnesium oxide, which is closely related to magnesium citrate. Some key points to consider when taking magnesium citrate include:
- Taking the supplement with food to minimize potential digestive upset
- Chilling the liquid form for better taste and following it with a full glass of water
- Not exceeding the recommended dosage to avoid diarrhea, abdominal cramping, and electrolyte imbalances
- Consulting a healthcare provider before using magnesium citrate, especially for those with kidney disease, heart conditions, or on certain medications The supplement works by drawing water into the intestines to soften stool and stimulate bowel movements, while also supporting muscle and nerve function, energy production, and bone health when used as a daily supplement. It's also worth noting that other studies, such as 1, 1, and 1, provide different dosing recommendations, but these are not as recent or directly relevant to the question of magnesium citrate dosing for adults. In terms of specific dosing, the most recent study 1 suggests starting at a lower dose, which may be increased if necessary, and avoiding use in patients with renal insufficiency due to the risk of hypermagnesemia. Overall, when considering the use of magnesium citrate, it's crucial to prioritize the most recent and highest quality evidence, while also taking into account individual patient factors and potential interactions with other medications.
From the FDA Drug Label
Directions shake well before using drink a full glass (8 ounces) of liquid with each dose may be taken as a single daily dose or in divided doses adults and children 12 years of age and over - 6.5 to 10 fl oz maximum 10 fl oz in 24 hours The recommended dose and frequency of magnesium citrate for adults is 6.5 to 10 fl oz, which may be taken as a single daily dose or in divided doses, with a maximum of 10 fl oz in 24 hours 2.
From the Research
Magnesium Citrate Dosage and Frequency
The recommended dose and frequency of magnesium citrate for adults vary depending on the purpose of use.
- For colorectal cleansing, a dose of 17.7 or 35.4 g of magnesium citrate is used, as reported in a study published in the journal Drugs 3.
- In another study, 400 mg of Mg from Mg citrate was used to assess bioavailability in Mg-saturated subjects 4.
- A study on the reduction of renal stone risk used a dose of 21 mEq of magnesium as potassium-magnesium citrate per day 5.
Administration and Bioavailability
- Magnesium citrate can be administered orally, and its bioavailability is higher compared to magnesium oxide 4.
- The bioavailability of magnesium citrate can be assessed by measuring urinary excretion and plasma magnesium levels 4.
- Magnesium citrate is not absorbed in detectable quantities when used as a colorectal cleansing agent 3.
Safety and Efficacy
- Magnesium citrate is generally well-tolerated, but high doses can cause hypermagnesemia, which may lead to severe refractory hypotension 6, 7.
- Patients with underlying medical conditions, such as anorexia nervosa or intestinal disease, may be at risk of developing hypermagnesemia when taking magnesium citrate 6, 7.
- Magnesium citrate is effective in reducing renal stone risk by increasing urine pH and citrate chelation of calcium 5.