Does Magnesium Interact with Lisinopril? A Guide to Safety

October 8, 2025 •

5 min read

Nearly 1 in 3 adults in the U.S. has high blood pressure, a primary reason for prescriptions like lisinopril [1.7.2]. Many also take magnesium, but does magnesium interact with lisinopril? This combination requires caution and medical guidance to ensure safety.

Quick Summary

Taking magnesium with lisinopril can enhance blood pressure-lowering effects, risking hypotension. Lisinopril also affects potassium levels, requiring careful electrolyte monitoring. Consulting a doctor before combining them is crucial.

Key Points

Additive Hypotension: The main risk is that both lisinopril and magnesium lower blood pressure, which can cause it to drop too low (hypotension) [1.5.1].
Potassium Levels: Lisinopril can increase potassium levels in the blood; therefore, electrolyte balance must be monitored by a doctor when adding magnesium [1.4.1, 1.9.1].
Consult a Doctor First: Always speak with your healthcare provider before combining lisinopril with magnesium supplements to assess risks and ensure safety [1.5.2].
Monitor for Symptoms: Be aware of symptoms of low blood pressure, such as dizziness, lightheadedness, and fainting, and report them to your doctor [1.8.3].
Kidney Function: Both substances are processed by the kidneys, so individuals with kidney disease require extra caution and monitoring [1.2.1].
Separate Doses: Taking magnesium at least two hours apart from lisinopril is often recommended to avoid potential absorption interference [1.5.2].
Start Low, Go Slow: If approved by a doctor, starting with a low dose of magnesium allows for monitoring of its effects on your blood pressure.

Understanding Lisinopril and Its Function

Lisinopril is a widely prescribed medication belonging to a class of drugs called angiotensin-converting enzyme (ACE) inhibitors [1.6.6]. Its primary use is to treat high blood pressure (hypertension) and heart failure [1.6.2]. The medication works by blocking the conversion of angiotensin I to angiotensin II, a potent chemical that causes blood vessels to constrict [1.6.1, 1.6.5]. By inhibiting this process, lisinopril helps relax blood vessels, which in turn lowers blood pressure and allows the heart to pump blood more efficiently [1.6.2, 1.6.6].

Beyond just lowering blood pressure, lisinopril has other beneficial effects. It can improve survival rates after a heart attack and help prevent long-term kidney damage, particularly in patients with diabetes [1.6.2, 1.6.3]. One of its key mechanisms involves reducing the secretion of aldosterone, a hormone that regulates salt and water balance [1.6.3]. This leads to increased excretion of sodium and water, further contributing to lower blood pressure. However, this effect on aldosterone also causes the body to retain potassium, which is a critical consideration for anyone taking the drug [1.4.1].

The Vital Role of Magnesium in the Body

Magnesium is an essential mineral that participates in hundreds of biochemical reactions in the body [1.7.5]. It is fundamental for maintaining normal muscle and nerve function, supporting a healthy immune system, keeping the heartbeat steady, and helping bones remain strong [1.7.5].

One of magnesium's most important roles is in cardiovascular health. The mineral helps regulate blood pressure by acting as a natural calcium channel blocker, which helps blood vessels relax [1.7.2, 1.5.2]. It also plays a part in managing the balance of other key electrolytes like sodium and potassium [1.7.2]. Studies have shown that adequate dietary intake of magnesium is associated with a lower risk of hypertension [1.7.2]. For this reason, many people with high blood pressure are interested in magnesium supplements as a complementary approach to their prescribed treatment. However, this is where the potential for interaction arises.

The Primary Interaction: Additive Blood Pressure Effects

The most significant interaction between lisinopril and magnesium is their combined effect on blood pressure. Since both substances can lower blood pressure, taking them together may enhance this effect, potentially leading to hypotension (abnormally low blood pressure) [1.5.1, 1.5.2].

Symptoms of hypotension can include:

Dizziness or lightheadedness [1.8.3]
Fainting (syncope) [1.8.2]
Blurred vision [1.8.3]
Nausea [1.8.2]
Fatigue and weakness [1.8.3, 1.8.2]
Confusion [1.8.2]

This risk is particularly pronounced for individuals on high doses of either lisinopril or magnesium, the elderly, or those who are dehydrated [1.9.1]. While some studies find no major interaction between certain forms of magnesium (like chelated magnesium) and lisinopril, the overarching advice is one of caution [1.3.2]. It is not a strict contraindication, but it requires careful management.

Impact on Electrolytes: The Potassium Connection

A secondary but equally important consideration is the effect on electrolytes, specifically potassium. Lisinopril is well-known for its potential to cause hyperkalemia (high potassium levels) because it reduces aldosterone, leading to potassium retention [1.4.1, 1.4.3]. Patients taking lisinopril are often advised to avoid high potassium intake, including potassium supplements and salt substitutes containing potassium chloride, unless directed by a doctor [1.3.2, 1.9.2].

While some research indicates that ACE inhibitors are not major culprits in altering magnesium levels, the complex interplay of electrolytes means that any changes should be monitored [1.2.6]. Combining lisinopril with magnesium supplements should always be done under medical supervision, which includes regular blood tests to check both potassium and magnesium levels to prevent dangerous imbalances [1.9.1].

Does Magnesium Affect Lisinopril Absorption?

Some forms of magnesium, particularly magnesium oxide, can act as an antacid. Antacids may potentially decrease the absorption of ACE inhibitors by altering stomach pH [1.2.2]. To minimize any potential impact on bioavailability, a common recommendation is to separate the administration times. Taking a magnesium supplement at least two hours apart from lisinopril can help ensure that both are absorbed properly and reduce the risk of this pharmacokinetic interaction [1.5.2].


Feature	Lisinopril	Magnesium	Combined Effect
Primary Action	Blocks angiotensin II production, lowers blood pressure [1.6.1]	Relaxes blood vessels, acts as a natural calcium blocker [1.7.2]	Potential for additive hypotensive effects (low blood pressure) [1.5.1]
Effect on Potassium	Can increase potassium levels (hyperkalemia) [1.4.1]	Helps regulate electrolyte balance [1.7.2]	Requires careful monitoring of potassium levels [1.9.1]
Effect on Kidneys	Protects kidneys in some cases; can affect function [1.6.3, 1.2.1]	Excreted by kidneys; caution in renal impairment [1.7.2]	Increased need for kidney function monitoring, especially if pre-existing disease [1.2.1]
Common Side Effects	Dry cough, dizziness, headache [1.6.2]	Diarrhea, stomach cramps (with high doses) [1.5.2]	Dizziness, lightheadedness due to low blood pressure [1.8.1]

Expert Recommendations for Safe Use

While a significant interaction is not always reported, the consensus among healthcare professionals is to approach the combination of lisinopril and magnesium with caution [1.3.2, 1.3.6]. The following steps are recommended:

Consult Your Doctor: Before starting any new supplement, including magnesium, speak with your healthcare provider. They can assess your individual health status, including kidney function and current electrolyte levels, to determine if it is safe for you [1.5.2].
Start with a Low Dose: If your doctor approves, they will likely recommend starting with a low dose of magnesium and monitoring your blood pressure and any symptoms of hypotension closely.
Regular Monitoring: Expect your doctor to order periodic blood tests to monitor your potassium, magnesium, and creatinine (a measure of kidney function) levels [1.9.1].
Timing Matters: Separate the doses of lisinopril and magnesium by at least two hours to prevent any potential absorption issues [1.5.2].
Know the Symptoms: Be aware of the signs of both hypotension and hyperkalemia (weakness, tingling, irregular heartbeat) and seek medical attention if they occur [1.8.3, 1.9.1].

Conclusion

So, does magnesium interact with lisinopril? Yes, a moderate interaction exists, primarily centered on their shared ability to lower blood pressure, which can lead to hypotension if not properly managed. Furthermore, the effect of lisinopril on potassium levels necessitates careful electrolyte monitoring when adding another supplement to your regimen. The interaction is not typically severe enough to forbid the combination entirely, but it requires a responsible and medically supervised approach. Communication with your healthcare provider is the most critical step to ensure you can safely benefit from both your prescribed medication and any supplements you wish to take.

For more information on the mechanism of ACE inhibitors, you can visit the FDA's page on Zestril (lisinopril). [1.6.5]

Frequently Asked Questions

It can be safe, but it requires caution and medical supervision. The main risk is an additive effect that could lower your blood pressure too much. Always consult your doctor before starting magnesium supplements if you take lisinopril [1.5.1, 1.5.2].

The primary symptoms are those of hypotension (low blood pressure), which include dizziness, lightheadedness, blurred vision, fatigue, and fainting [1.8.3].

To prevent potential issues with absorption, it's generally recommended to take magnesium supplements at least 2 hours before or after your lisinopril dose [1.5.2].

Both lisinopril and magnesium can affect kidney function, especially in those with pre-existing kidney disease. Combining them may require more frequent monitoring of your kidney health by a doctor [1.2.1].

While some diuretics deplete magnesium, ACE inhibitors like lisinopril are not generally considered to be major culprits of magnesium depletion [1.2.6]. However, lisinopril does affect other electrolytes like potassium [1.4.1].

While some data suggests chelated forms of magnesium may have fewer interactions, there is no definitive 'best' type [1.3.2]. The most important factor is discussing any form of magnesium with your doctor to determine the right choice and dose for you.

Yes, lisinopril can cause hyperkalemia (high potassium) by reducing the body's ability to excrete it. This is a key reason why electrolyte levels must be monitored when taking this medication, especially if other supplements are added [1.4.1, 1.4.3].