Can Lisinopril Cause Memory Loss?

Lisinopril is not widely recognized as a drug that causes memory loss, but a small body of research suggests it may have subtle negative effects on certain aspects of cognition, particularly attention and learning, that go beyond what would be expected from its blood-pressure-lowering action alone. The picture is more complicated than a simple yes or no, because untreated high blood pressure itself damages the brain over time, and stopping lisinopril without a replacement could be worse than any cognitive side effect the drug might carry.

What Research Has Found About Lisinopril and Cognition

The most direct evidence comes from a pilot study that measured lisinopril blood concentrations in patients and correlated them with cognitive test scores. Higher lisinopril levels were linked to worse performance on tests of attention, perceptual motor skills, and learning. The relationship was concentration-dependent, meaning more drug in the blood correlated with more cognitive difficulty, and the researchers noted this effect was not simply a consequence of lower blood pressure.¹ That last point matters. If lisinopril’s cognitive effects were just from lowering blood pressure too aggressively, you’d expect any blood pressure drug to do the same at equivalent doses. The fact that the effect tracked with lisinopril concentration independently of blood pressure hints at something more drug-specific.

A randomized clinical trial in older adults with mild cognitive impairment compared lisinopril head-to-head with candesartan, a different type of blood pressure medication called an angiotensin receptor blocker (ARB). After 12 months, the candesartan group showed improved executive function, while the lisinopril group showed decline. On a timed cognitive task, the candesartan group averaged about 128 seconds compared to 150 seconds for the lisinopril group, a meaningful gap in a clinical setting.² This doesn’t mean lisinopril made people forget where they put their keys. Executive function is more about mental flexibility, planning, and the ability to switch between tasks. But for someone already experiencing mild cognitive difficulties, that kind of decline is exactly what they’d notice and worry about.

A separate trial in elderly patients with high blood pressure compared a telmisartan combination to a lisinopril combination over 24 weeks. The telmisartan group showed significant improvements in word-list memory and recall, while the lisinopril group showed no meaningful change in any cognitive measure across the entire study period.³ Again, the lisinopril group didn’t dramatically worsen, but they didn’t improve either, while an alternative drug actively helped cognition.

Why Lisinopril Might Behave Differently from Other Blood Pressure Drugs

Lisinopril belongs to the ACE inhibitor class, which works by blocking an enzyme called angiotensin-converting enzyme. ARBs like candesartan and telmisartan target the same hormonal system but at a different point. Both lower blood pressure effectively, but their effects on brain tissue can differ substantially because the enzyme ACE does more than just regulate blood pressure.

One important distinction among blood pressure drugs is whether they cross the blood-brain barrier, the tightly sealed layer that separates your brain’s blood supply from brain tissue itself. Among ACE inhibitors, some cross this barrier and some do not. Lisinopril is generally classified as one that does not cross it well, which you might think would protect the brain from direct drug effects. But the research tells a more nuanced story. A study tracking over 1,600 patients with Alzheimer’s disease found that users of ACE inhibitors that do not cross the blood-brain barrier had the worst cognitive trajectory compared to every other group. People taking brain-penetrating ACE inhibitors, brain-penetrating ARBs, and even non-brain-penetrating ARBs all showed slower decline in delayed recall than users of non-brain-penetrating ACE inhibitors.⁴

This is a puzzling finding, and researchers are still working out why. One theory involves ACE’s role in clearing amyloid beta, the protein that accumulates in Alzheimer’s disease. Animal research has shown that boosting ACE activity in certain immune cells helps clear amyloid from the brain.⁵ If ACE helps clean up amyloid, then blocking ACE with a drug like lisinopril could theoretically reduce that cleanup. However, direct testing in mouse models of Alzheimer’s disease found that the ACE inhibitor captopril did not actually increase amyloid accumulation.⁶ So the amyloid angle remains uncertain. The cognitive differences between drug classes may ultimately come down to something other than amyloid, or the mouse models may not capture what happens in humans over years of use.

The Blood Pressure Paradox and Your Brain

Before anyone considers stopping lisinopril over cognitive concerns, there’s a critical fact to keep in mind: untreated high blood pressure is one of the most well-established causes of memory loss and cognitive decline. Chronically elevated blood pressure damages small blood vessels throughout the brain, reducing blood flow to areas essential for memory and thinking.⁷ Over years, this vascular damage contributes to what doctors call vascular cognitive impairment, which can look and feel a lot like early Alzheimer’s disease.

So the question isn’t really “does lisinopril hurt my brain?” in isolation. It’s “does lisinopril hurt my brain more than uncontrolled blood pressure would?” For the vast majority of people, the answer is clearly no. The cognitive risks of uncontrolled hypertension dwarf any subtle effects that lisinopril might have. The more useful question is whether a different blood pressure medication might protect your brain better while still controlling your blood pressure just as well.

There is an interesting wrinkle on the other end of the spectrum, too. Lowering blood pressure too aggressively can also harm cognition. Research from the SPRINT-MIND trial found that when treated diastolic blood pressure (the bottom number) drops very low, cerebral blood flow decreases. For every 5 mm Hg increase in achieved diastolic blood pressure, there was a roughly 2 mL/100g per minute increase in cerebral blood flow.⁸ In other words, if your blood pressure drops too low on lisinopril, your brain might not be getting enough blood to function optimally. This effect wasn’t specific to any one drug, but it highlights that any blood pressure medication, if dosed too aggressively, can impair cognitive function through sheer under-perfusion of the brain.

Hyponatremia and Cognitive Fog

There’s another, more indirect route by which lisinopril can affect your thinking that many people never connect to their blood pressure pill. ACE inhibitors can occasionally cause hyponatremia, a drop in blood sodium levels.⁹ Even mild hyponatremia produces symptoms that overlap significantly with what people describe as “memory problems”: confusion, difficulty concentrating, mental sluggishness, and feeling generally foggy. In older adults, who are both more likely to take lisinopril and more vulnerable to electrolyte imbalances, this effect can be particularly pronounced.

The tricky part is that mild hyponatremia doesn’t always show up on routine blood work unless your doctor is specifically looking for it. If you’ve been on lisinopril for a while and gradually started feeling mentally slower, it’s worth asking your doctor to check your sodium levels. This is one of the most fixable causes of cognitive symptoms in people taking ACE inhibitors, and it gets overlooked because both patients and doctors tend to assume that “brain fog” is either normal aging or something untreatable.

How ARBs Compare for Brain Health

Across several lines of evidence, ARBs consistently outperform ACE inhibitors like lisinopril when it comes to cognitive outcomes. The randomized trial comparing candesartan and lisinopril found candesartan actively improved executive function while lisinopril was associated with decline.² The telmisartan trial showed memory improvements that lisinopril failed to produce.³ And the observational study of Alzheimer’s patients found that ARB users experienced roughly 9% slower decline in delayed recall over about two years compared to ACE inhibitor users.⁴

This doesn’t mean every person on lisinopril should immediately switch to an ARB. Both drug classes are well-established treatments for high blood pressure, and lisinopril has decades of evidence supporting its benefits for heart and kidney health. But for someone who is already experiencing cognitive symptoms, or who has a family history of dementia and is concerned about long-term brain health, the evidence provides a reasonable basis for discussing a switch with their doctor. ARBs like candesartan, telmisartan, and losartan are widely available and similarly priced. The conversation is worth having, especially for older adults.

What Stopping Blood Pressure Medication Does to Cognition

A Cochrane review looked at whether withdrawing blood pressure medication could actually improve cognitive outcomes. The evidence was extremely limited. One relevant study examined patients who temporarily stopped their blood pressure medications for seven days after a stroke. At 90 days, the group that stopped medications scored slightly higher on cognitive screening tests, about 1 to 2 points on standardized measures.¹⁰ That’s a tiny effect and a very specific scenario, applying to post-stroke patients, not the general population. The review concluded there simply isn’t enough evidence to recommend stopping blood pressure drugs as a cognitive strategy.

This is worth emphasizing because people who Google “can lisinopril cause memory loss” are sometimes looking for permission to stop taking it. The risks of doing so, including stroke, heart attack, and kidney damage, are severe and well-documented. If lisinopril is causing you cognitive problems, the answer is almost always switching to a different medication, not going without one.

Not All ACE Inhibitors Are the Same

The pilot study that found concentration-dependent cognitive effects with lisinopril also tested enalapril, another popular ACE inhibitor. Enalapril did not show the same negative pattern. In fact, enalapril appeared to perform better than lisinopril on measures of attention and visuospatial orientation.¹ This suggests the cognitive effects aren’t a blanket property of all ACE inhibitors but may be specific to individual drugs within the class. Enalapril crosses the blood-brain barrier more readily than lisinopril, which may paradoxically be protective, possibly because it can modulate the brain’s own renin-angiotensin system in a way that lisinopril, stuck mostly outside the brain, cannot.

If you’re taking an ACE inhibitor and don’t want to switch to an entirely different drug class, asking about enalapril or another brain-penetrating ACE inhibitor like perindopril or ramipril could be a reasonable middle step. The evidence here is still thin, and much of it comes from small studies, so this is a conversation for your doctor rather than a self-guided medication change.

When to Worry and When to Wait

Cognitive symptoms are extremely common and have dozens of potential causes. Sleep deprivation, stress, depression, thyroid problems, vitamin B12 deficiency, and normal aging can all produce the kind of forgetfulness and mental fog that people sometimes attribute to a medication. If you started lisinopril recently and noticed a clear change in your thinking within weeks, there’s a reasonable chance the drug is involved. If you’ve been on lisinopril for years and your memory has been gradually slipping, the more likely culprits are aging itself, the cumulative effects of high blood pressure on your blood vessels, or an unrelated condition.

A useful self-check is to consider when your symptoms started relative to when you began the medication or had a dose increase. Drug-related cognitive effects tend to track with changes in dose or drug levels. Gradual decline over years is less likely to be medication-related and more likely to reflect an underlying process that would benefit from medical evaluation in its own right.

If your doctor checks your sodium levels, confirms they’re normal, and your blood pressure isn’t dropping excessively low, the case for lisinopril as the culprit becomes weaker. At that point, a thorough cognitive workup looking at other causes becomes more productive than switching blood pressure medications and hoping for the best. That said, with evidence suggesting ARBs offer a cognitive advantage over ACE inhibitors, there’s little downside to trying a switch if both you and your doctor are comfortable with it, since the blood pressure benefit is comparable and the potential upside for your brain makes the trade-off favorable.

ACE in the Brain Is More Than a Blood Pressure Regulator

Part of what makes this topic so unsettled is that the angiotensin-converting enzyme does things in the brain that have nothing obvious to do with blood pressure. ACE is involved in breaking down certain neuropeptides, modulating inflammation, and interacting with immune cells. The finding that overexpressing ACE in immune cells helps clear amyloid beta in animal models suggests the enzyme plays a housekeeping role in the brain that we are only beginning to understand.⁵ Blocking that enzyme with a drug might have consequences that don’t show up in short-term blood pressure trials but accumulate over years of use.

At the same time, the captopril study in mouse models of Alzheimer’s disease found no increase in amyloid accumulation with ACE inhibitor treatment, which complicates a clean narrative.⁶ The brain’s response to ACE inhibition is clearly not as simple as “block the enzyme, lose the benefit.” Different ACE inhibitors, different durations of treatment, different genetic backgrounds, and different stages of brain aging may all shift the balance in ways current research hasn’t fully mapped. For now, the clinical data showing cognitive advantages for ARBs over ACE inhibitors in humans is more actionable than the still-evolving animal research on mechanism.

1
PubMed Central. The Correlation between Two Angiotensin-Converting Enzyme Inhibitor’s Concentrations and Cognition
2
JAMA Network Open. Effects of Candesartan vs Lisinopril on Neurocognitive Function in Older Adults With Executive Mild Cognitive Impairment: A Randomized Clinical Trial
3
PubMed. Effect of telmisartan/hydrochlorothiazide vs lisinopril/hydrochlorothiazide combination on ambulatory blood pressure and cognitive function in elderly hypertensive patients
4
PubMed Central. The use of angiotensin-converting enzyme inhibitors vs. angiotensin receptor blockers and cognitive decline in Alzheimer’s disease: the importance of blood-brain barrier penetration and APOE ε4 carrier status
5
PubMed Central. Angiotensin-converting enzyme overexpression in mouse neutrophils prevents Alzheimer’s-like cognitive decline
6
PubMed Central. Effects of prolonged angiotensin-converting enzyme inhibitor treatment on amyloid beta-protein metabolism in mouse models of Alzheimer disease
7
PubMed. Patient page. Untreated hypertension can lead to memory loss by cutting down on blood flow to the brain
8
Lippincott Williams & Wilkins / AHA Journals (Circulation: Cardiovascular Quality and Outcomes). Diastolic Blood Pressure and Cognitive Function in Adults With Achieved Systolic Blood Pressure Below 130 mm Hg: Insights From the SPRINT-MIND Trial
9
PubMed Central. Hyponatremia Secondary to Lisinopril in a Veteran Patient
10
PubMed Central. Antihypertensive withdrawal for the prevention of cognitive decline