From the FDA Drug Label
PRINCIPAL DISPLAY PANEL - 30 mL Cup Tray Label NDC 0121-0431-30 Milk of Magnesia USP ANTACID, SALINE LAXATIVE Each 30 mL contains: Magnesium Hydroxide 2400 mg Active ingredient (in each 5 mL) Magnesium hydroxide 400 mg
The FDA drug label does not answer the question.
From the Research
Magnesium supplements may help with insomnia, with a recommended dose of 175mg to 500mg taken about an hour before bedtime, as shown in studies such as 1 and 2. The most effective form of magnesium for insomnia is not well established, but magnesium glycinate, citrate, or threonate are often recommended due to their better absorption and fewer digestive side effects. Some key points to consider when taking magnesium supplements for insomnia include:
- Starting with a lower dose (around 175mg) and increasing gradually if needed, as higher doses may cause digestive upset including diarrhea
- Taking the supplement consistently each night, as benefits may take several weeks to become noticeable
- Combining magnesium supplementation with good sleep hygiene practices like maintaining a regular sleep schedule and avoiding screens before bedtime
- Being aware that magnesium works by regulating neurotransmitters that calm the nervous system and by helping to maintain healthy levels of GABA, which promotes relaxation
- Consulting a doctor before taking magnesium supplements if you have kidney problems, as shown in study 2 The study 1 found that a combination of magnesium, melatonin, and vitamin B complex supplementation had a beneficial effect on insomnia symptoms, with a significant reduction in insomnia severity after 3 months of treatment. However, the study 3 found that the quality of literature on the use of oral magnesium for insomnia is substandard, and more research is needed to confirm its effectiveness. The most recent study 4 found that there is an association between magnesium status and sleep quality, but the evidence is not strong enough to make a definitive recommendation. Overall, while the evidence is not conclusive, magnesium supplements may be a useful adjunct to other treatments for insomnia, and a dose of 175mg to 500mg per day may be effective in improving sleep quality.