Proton pump inhibitors are among the most widely prescribed drug classes in the world, and a substantial proportion of the men taking them have been doing so for years rather than weeks. The question of whether proton pump inhibitors and erectile dysfunction are connected has moved, over the past decade, from scattered case reports to a body of mechanistic and pharmacoepidemiologic work that deserves a careful reading. The evidence is not uniform, and it does not support alarm. It does support the idea that chronic acid suppression is not biologically inert, and that a man presenting with new erectile difficulty while on long-term omeprazole warrants a medication review alongside the usual vascular and metabolic workup.
The Pharmacovigilance Signal
The largest dataset addressing this question directly is a 2026 analysis of VigiBase, the World Health Organization's international pharmacovigilance database, published in Drug Safety. The investigators retrieved every individual case safety report involving omeprazole, lansoprazole, rabeprazole, pantoprazole or esomeprazole as a suspected or interacting drug through September 2024 — 420,598 reports in total — and isolated those containing a preferred term from the standardised MedDRA query for sexual dysfunction [1].
Disproportionality analysis, adjusted with Bonferroni correction for multiple testing, identified a statistically significant signal for omeprazole and erectile dysfunction, with a reporting odds ratio of 1.76 (95% CI 1.54–2.01). Because sexual function declines with age independently of any drug exposure, the authors repeated the analysis restricted to men aged 18 to 64. The signal held, and strengthened slightly, at a reporting odds ratio of 1.80 (95% CI 1.49–2.16). The restricted analysis also surfaced two additional signals in male patients: decreased libido with omeprazole (ROR 1.49; 95% CI 1.05–2.12) and hypogonadism with esomeprazole (ROR 5.22; 95% CI 1.22–22.34), the latter with a confidence interval wide enough to demand caution [1].
Disproportionality analysis measures reporting patterns, not incidence. It cannot establish causation, quantify absolute risk, or rule out reporting bias, and the authors state plainly that observational studies are needed to validate these signals. What it does establish is that the question is no longer hypothetical.
The Nitric Oxide Mechanism
Erection is a nitric-oxide-dependent event. Endothelial and neuronal nitric oxide synthase generate nitric oxide, which drives cyclic GMP production in cavernosal smooth muscle and produces the vasodilation and sinusoidal filling that make an erection possible. Anything that reduces nitric oxide bioavailability narrows the physiological margin on which erectile function depends.
A 2013 Circulation paper proposed a specific route by which proton pump inhibitors might do exactly that. Asymmetric dimethylarginine, or ADMA, is an endogenous inhibitor of nitric oxide synthase, and elevated plasma ADMA is an established cardiovascular risk marker. The enzyme that clears it is dimethylarginine dimethylaminohydrolase, or DDAH. The investigators found that proton pump inhibitors bind to and inhibit DDAH, raising plasma ADMA, lowering nitric oxide levels, and reducing endothelium-dependent vasodilation in a murine model and in ex vivo human tissue [2].
Animal work has since added a second, parallel mechanism. In rats treated with omeprazole, endothelium-dependent aortic relaxation to acetylcholine was impaired without any rise in blood pressure, accompanied by increased xanthine oxidoreductase activity and elevated markers of vascular oxidative stress. Blocking xanthine oxidoreductase with febuxostat abolished the effect, which suggests that oxidative stress is not merely an accompaniment but part of the causal chain [3].
What Human Studies Have and Have Not Shown
Mechanistic plausibility is not clinical proof, and the human data are appropriately mixed. A prospective open-label crossover pilot enrolled 21 adults — 11 healthy, 10 with established cardiovascular disease — and alternated four weeks of lansoprazole 30 mg with four weeks of placebo, separated by a two-week washout, measuring endothelial function by peripheral arterial tonometry and plasma ADMA before and after each interval. ADMA worsened more during the proton pump inhibitor phase than during placebo, and the trend was more pronounced in participants with vascular disease, but the differences did not reach statistical significance and flow-mediated vasodilation was not impaired. With 21 participants, the study was not powered to detect a modest effect [4].
A larger population-based analysis took a different measurement approach. Drawing on 1,298 participants from two cohorts of the Study of Health in Pomerania, of whom 87 were regular daily proton pump inhibitor users, the investigators reasoned that plasma ADMA may not reflect intracellular ADMA and therefore examined plasma citrulline as a marker of DDAH inhibition alongside brachial artery flow-mediated dilation. In fully adjusted models, proton pump inhibitor users showed a 0.99 percent lower flow-mediated dilation (95% CI −1.96 to −0.02) and lower plasma citrulline [5].
A one-percent absolute reduction in flow-mediated dilation is a small effect, and the confidence interval nearly touches zero. In a man with otherwise healthy vasculature it is unlikely to be noticeable. Layered onto existing endothelial impairment from diabetes, hypertension, smoking or metabolic syndrome, a small additional decrement is more consequential, because erectile function is frequently the first territory in which cumulative vascular loss becomes symptomatic.
The Hormonal Dimension
A separate line of evidence points away from the endothelium entirely. A cross-sectional study of 65 men taking proton pump inhibitors regularly for at least three months compared those with sexual complaints against those without. The two groups differed significantly in mean serum prolactin, sex hormone binding globulin, total testosterone and progesterone, with prolactin markedly higher in the symptomatic group. When men were instead stratified by prolactin status, the hyperprolactinemic users reported significantly more decreased libido and erectile dysfunction than the normoprolactinemic users [6].
This is a small, single-region, cross-sectional study, and it cannot establish direction of causation. It is nonetheless mechanistically coherent. Elevated prolactin suppresses gonadotropin-releasing hormone pulsatility, lowers testosterone, and independently reduces libido — a well-characterised pathway with nothing to do with nitric oxide. It also has a practical implication: in a man on long-term acid suppression with new low desire as well as erectile difficulty, a serum prolactin and a morning total testosterone are reasonable additions to the workup.
The Absorption Problem Nobody Mentions
There is a fourth consideration that is purely pharmacokinetic and easily overlooked. Sildenafil citrate is poorly water soluble and its solubility is strongly pH dependent, falling from 37.25 mg/mL at pH 1.2 to 0.22 mg/mL at pH 8.0. Raising gastric pH should therefore reduce dissolution and absorption. In a rat pharmacokinetic study, the relative systemic bioavailability of a conventional sildenafil tablet fell significantly when co-administered with omeprazole. A sildenafil orally disintegrating tablet, which dissolves before reaching the stomach, was unaffected by the same proton pump inhibitor exposure [7].
Extrapolating rodent pharmacokinetics to humans requires caution, and the finding is specific to sildenafil rather than to the whole PDE5 inhibitor class. But it raises a possibility worth keeping in mind clinically: a man on chronic acid suppression who reports that an oral PDE5 inhibitor has stopped working may not have progressive vascular disease. He may have a dissolution problem. That distinction changes the response — a formulation that dissolves in the mouth rather than the stomach is a different intervention from a dose escalation, and it is one reason chewable and sublingual delivery has become more clinically interesting than the convenience framing suggests.
Putting It Together
None of this is a reason to stop a proton pump inhibitor that is genuinely indicated. Erosive esophagitis, Barrett's esophagus, ulcer prophylaxis on chronic NSAIDs and Zollinger-Ellison syndrome all justify long-term therapy, and untreated reflux disease carries its own real risks. The more common problem is indication drift: a course started for a self-limiting complaint that was never formally reassessed and has now run for six years on repeat prescription.
A reasonable approach is straightforward. Review whether the original indication still holds, and if it does not, discuss stepping down to on-demand dosing or an H2 blocker with the prescribing physician rather than stopping abruptly, since rebound acid hypersecretion is a recognised phenomenon. If sexual symptoms are present, check prolactin and morning testosterone. Because long-term acid suppression can reduce absorption of magnesium and vitamin B12, both of which matter for vascular and neurological function, periodic assessment of those is sensible. And treat new erectile dysfunction as the vascular signal it usually is, with blood pressure, lipids, HbA1c and a genuine cardiovascular risk assessment — a medication signal this modest should never displace that workup. Further reading on the vascular basis of erectile function is available on the OnyxMD blog.
Conclusion
The relationship between proton pump inhibitors and erectile dysfunction is best described as a plausible, modest and incompletely characterised contributor rather than a primary cause. The pharmacovigilance signal for omeprazole is real and survives age restriction. The DDAH-ADMA mechanism is well described in preclinical models, and population data suggest a small measurable decrement in endothelial function among daily users. The hormonal pathway is supported by limited but coherent evidence. For most men, this sits several tiers below diabetes, smoking, hypertension and obesity in clinical importance. For a man already carrying vascular risk, it is one more removable variable — and removable variables are worth finding.
If you're exploring clinically-formulated options, OnyxMD offers physician-supervised treatment plans starting with a free online assessment at questionnaire.getonyxmd.com. EPIQ CHEWS combines daily low-dose tadalafil and vardenafil with vitamin D3 and K2 in a chewable format, and is prescribed only after physician review.
These statements have not been evaluated by the FDA. This content is for informational purposes only and does not constitute medical advice.
References
Crisafulli S, Ciccimarra F, Scapini F, L'Abbate L, Jannini EA, De Martino MC, Giannetta E, Mestres J, Tuccori M, Trifirò G. Sexual dysfunctions associated with proton pump inhibitors: insights from VigiBase, the World Health Organization pharmacovigilance database. Drug Safety. 2026;49(4):435-447. doi:10.1007/s40264-025-01626-6
Ghebremariam YT, LePendu P, Lee JC, Erlanson DA, Slaviero A, Shah NH, Leiper J, Cooke JP. Unexpected effect of proton pump inhibitors: elevation of the cardiovascular risk factor asymmetric dimethylarginine. Circulation. 2013;128(8):845-853. doi:10.1161/CIRCULATIONAHA.113.003602
Pinheiro LC, Oliveira-Paula GH, Portella RL, Guimarães DA, de Angelis CD, Tanus-Santos JE. Omeprazole impairs vascular redox biology and causes xanthine oxidoreductase-mediated endothelial dysfunction. Redox Biology. 2016;9:134-143. doi:10.1016/j.redox.2016.08.001
Ghebremariam YT, Cooke JP, Khan F, Thakker RN, Chang P, Shah NH, Nead KT, Leeper NJ. Proton pump inhibitors and vascular function: a prospective cross-over pilot study. Vascular Medicine. 2015;20(4):309-316. doi:10.1177/1358863X14568444
Nolde M, Bahls M, Friedrich N, Dörr M, Dreischulte T, Felix SB, Rückert-Eheberg IM, Ahn N, Amann U, Schwedhelm E, Völzke H, Lerch MM, Linseisen J, Meisinger C, Baumeister SE. Association of proton pump inhibitor use with endothelial function and metabolites of the nitric oxide pathway: a cross-sectional study. Pharmacotherapy. 2021;41(2):198-204. doi:10.1002/phar.2504
Ashfaq M, Khan Q, Haroon MZ, Abid SMA, Sharif MJH, Alkahraman YM. Long-term proton pump inhibitor therapy and its effect on endocrine hormones in selected patient population. Hormone and Metabolic Research. 2023;55(3):205-211. doi:10.1055/a-2009-9629
Shih CY, Chen CY, Lin HT, Liao YJ, Liang YJ. Oral bioavailability and pharmacokinetics of sildenafil orally disintegrating tablets under various gastric pH levels following administration of omeprazole in rats. Life (Basel). 2023;13(11):2126. doi:10.3390/life13112126
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