Why do we keep repeating “ARBs are ED-neutral or even beneficial” as if it’s universally true? I keep seeing real-world reports that don’t fit the narrative, especially with losartan. If losartan is supposed to help endothelial function, why do some people get worse erectile quality after starting it?
Here are angles I don’t see discussed much that might explain losartan-related ED for a subset:
- Combo pills vs monotherapy: Is the ED blamed on losartan actually coming from the HCTZ add-on? Thiazides are notorious for sexual side effects (and possible zinc depletion), but the combo gets lumped under “losartan.”
- Blood pressure targets and timing: If you drive MAP too low (or dose at night), does that blunt nocturnal tumescence or reduce perfusion during arousal? Anyone notice differences when dosing morning vs evening?
- Phenotype matters: Renin profile, salt sensitivity, baseline vascular stiffness. Could low-renin patients be more prone to erection issues on ARBs than on CCBs?
- Genetics and endothelial biology: AGTR1/ACE/eNOS polymorphisms could change the erectile response to angiotensin blockade. Has anyone seen data linking these to ED outcomes on losartan?
- Drug interactions and metabolism: Losartan’s active metabolite (E-3174) depends on CYP2C9/3A4. Do inhibitors/inducers (e.g., azoles, amiodarone, certain anticonvulsants) shift effect enough to impact erection quality via BP swings or endothelial effects?
- Sympathetic tone and CNS effects: Some report fatigue, lightheadedness, or sleep changes on losartan. Could that indirectly kill libido/erectile performance even if penile hemodynamics are “fine” on paper?
- “Improved” erection vs libido: Trials often conflate satisfaction scores with mechanical function. Anyone parse out libido, erection hardness, and stamina separately on losartan?
- Interaction with PDE5 inhibitors: Clinically “safe,” yes-but does the combo tip some people into symptomatic hypotension during sex? Any difference when spacing doses or lowering ARB dose on days using PDE5s?
If you’ve experienced ED on losartan (monotherapy), can you share:
- Dose, time of dosing, and whether you’re on a combo (HCTZ or not)
- Baseline and on-treatment BP/HR, especially morning vs evening
- What changed (libido, morning wood, erection hardness, maintenance)
- Co-meds (SSRIs, finasteride, beta-blocker, statin, alcohol/cannabis/nicotine)
- Whether switching within class (to valsartan/telmisartan) or to a CCB/ACEi fixed it
Has anyone done an n-of-1 crossover (with their prescriber): losartan vs amlodipine at equivalent BP control while logging morning erections and EHS? Also curious if anyone’s seen differences across generics/excipients.
Bottom line: is “losartan helps ED” a population average that hides important subgroups? If so, what’s the practical playbook to identify who does better on ARB vs CCB vs ACEi without months of trial-and-error?