Magnesium and Alcohol: Does Drinking Deplete Magnesium?

Magnesium and alcohol are linked in a well-documented way: alcohol makes the kidneys flush out more magnesium, and low magnesium is common in people who drink heavily for years. That does not mean a night out leaves you deficient. In healthy people, the kidneys usually rebalance quickly, and small studies found no lasting change in magnesium balance from short-term drinking. Taking magnesium for a hangover is a popular idea with no clinical trials behind it. This guide explains who is actually at risk of low magnesium, the signs that need a blood test, and what to check on magnesium supplement labels if you drink.

Peptide Labs sells products that contain magnesium, but this article does not recommend any of them. It is general information, not medical advice.

Magnesium and alcohol: what happens in the body

Alcohol acts on the kidneys in two ways that matter here. According to NIAAA, it suppresses vasopressin, the hormone that tells the kidneys to hold on to water, so you urinate more and lose extra fluid. It also raises the amount of magnesium in that urine. A small 1969 study in three healthy volunteers found a marked rise in urinary magnesium right after drinking. A 2008 review in Magnesium Research reported that urinary magnesium excretion can rise two to three fold with alcohol, while blood levels tend to fall.

Normally the kidneys are very good at protecting magnesium. The NIH Office of Dietary Supplements (ODS) explains that low magnesium from diet alone is uncommon in otherwise-healthy people because the kidneys cut back on what they excrete when intake is low. Long-term heavy drinking interferes with exactly that safety net.

Does alcohol deplete magnesium?

It depends on how much and for how long. In the 1969 study, drinking daily for eight days caused no significant change in overall magnesium balance, even though urine losses rose after each drink. The picture is different with chronic heavy drinking. A 2021 meta-analysis of 25 studies found that both total and ionized blood magnesium were markedly lower in people with chronic alcohol use disorder, that magnesium in muscle tissue was reduced, and that the kidneys’ normal response to low magnesium was blunted. The studies varied a lot, but the direction was consistent.

ODS calls magnesium deficiency common in people with chronic alcoholism and lists several contributors besides urine loss:

• Poor diet and overall nutrition.
• Vomiting, diarrhea and fatty stools, including from pancreatitis.
• Kidney changes that send extra magnesium into the urine.
• Low phosphate and low vitamin D.
• Alcoholic ketoacidosis and hormone changes linked to liver disease.

Signs of low magnesium and when to get tested

ODS lists loss of appetite, nausea, vomiting, fatigue and weakness as early signs of magnesium deficiency. As it worsens, numbness, tingling, muscle cramps, seizures, personality changes and abnormal heart rhythms can occur, and severe deficiency can pull blood calcium and potassium down too. Many of these symptoms overlap with the effects of heavy drinking itself, which is one reason self-diagnosis does not work.

Testing belongs with a clinician. ODS notes that assessing magnesium status is difficult because most of the body’s magnesium sits inside cells and bone, and the common serum test does not fully reflect total body stores. Other people at higher risk include older adults, people with digestive disorders and people taking loop or thiazide diuretics or acid-reducing proton pump inhibitors for more than a year. If you are worried about your drinking, or someone else’s, help is free and confidential. The SAMHSA National Helpline (1-800-662-4357) offers referrals and information 24 hours a day in English and Spanish, and you can call or text 988 to reach the 988 Lifeline, which also supports people with alcohol or drug use concerns. Stopping suddenly after heavy daily drinking can cause withdrawal, which MedlinePlus says can become a medical emergency; seizures, hallucinations, severe confusion, fever or an irregular heartbeat mean calling 911.

Is the magnesium hangover idea backed by evidence?

Not so far. A magnesium hangover remedy is easy to find online, usually built on the idea that drinking drains minerals. The trials have not tested it. A 2005 BMJ review of hangover trials found no compelling evidence for any remedy, and magnesium was not among the agents tested. A 2022 review of 21 placebo-controlled trials rated every efficacy result as very low quality, and magnesium was not among the few with a positive finding. NIAAA states that research has not linked the size of electrolyte changes to how bad a hangover feels, and has not shown that added electrolytes help.

NIAAA’s summary is blunt: no hangover remedy has been scientifically proven, and only time helps. For situations where fluid and mineral replacement really does matter, such as vomiting or diarrhea, see our guide to electrolytes.

Laxative forms, kidneys and medicines

If you use magnesium while drinking, a few label facts matter more than usual:

• Loose stools. ODS says the forms most often reported to cause diarrhea are carbonate, chloride, gluconate and oxide, and magnesium citrate is sold as an over-the-counter saline laxative. Alcohol already irritates the stomach, and diarrhea adds to fluid loss. Our guides to magnesium oxide and magnesium glycinate vs citrate compare the forms.
• Kidneys. ODS warns that the risk of magnesium toxicity rises with impaired kidney function. Ask a doctor first if you have kidney disease.
• Medicines. ODS advises taking bisphosphonates at least 2 hours apart from magnesium, and tetracycline or quinolone antibiotics at least 2 hours before or 4 to 6 hours after it. Diuretics and long-term acid reducers can lower magnesium further.
• Sedating blends. Many nighttime magnesium formulas also contain melatonin or herbs, and their labels often say not to combine them with alcohol.

Magnesium, alcohol and sleep

Some people take magnesium at night to offset poor sleep after drinking. NIAAA notes that alcohol helps people fall asleep faster but leaves sleep fragmented, with earlier waking. The evidence for magnesium and sleep is modest on its own, and a 2021 review of three small trials rated it low to very low quality; our article on magnesium for sleep walks through it. No study has tested whether magnesium changes sleep after drinking.

Labels we carry

Two examples show how differently magnesium can appear on a label:

• Let Loose capsules list magnesium as magnesium oxide at 95% of the Daily Value per capsule, plus an ozonated magnesium blend, and are marketed for regular bowel movements. The label says to ask a doctor before use if you have kidney disease and notes a possible laxative effect.
• cbdMD Broad Spectrum CBD PM Softgels include magnesium glycinate inside a proprietary blend, without a stated amount, alongside CBD and melatonin. The label warns of drowsiness and says not to combine them with alcohol or medication.

Ashwagandha shows up in many of the same nighttime blends; see our companion article on ashwagandha and alcohol. A seal from a testing program confirms label accuracy, not effects, as our guide to third-party tested supplements explains.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Follow the label and ask a healthcare provider before starting any supplement, especially if you take medicines or drink alcohol regularly. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Magnesium for Sleep: What the Research Shows and Which Forms Were Studied, Magnesium Oxide: Elemental Magnesium, Absorption, Laxative Effect and Safety, Electrolytes: What They Do, Who Needs Them and How to Read Labels.