Can Finasteride Lower Blood Pressure?
No, finasteride does not lower blood pressure in humans and is not indicated for hypertension management. The major hypertension guidelines do not list finasteride among blood pressure-lowering medications, and its mechanism of action—inhibiting 5α-reductase to reduce dihydrotestosterone—does not target cardiovascular pathways involved in blood pressure regulation 1.
Evidence from Hypertension Guidelines
The 2003 JNC 7 guidelines comprehensively list all classes of antihypertensive medications (thiazide diuretics, ACE inhibitors, ARBs, beta-blockers, calcium channel blockers, alpha-blockers) but do not include 5α-reductase inhibitors like finasteride 1.
The 2024 ESC hypertension guidelines similarly catalog established and emerging blood pressure-lowering therapies—including SGLT2 inhibitors, GLP-1 agonists, and novel aldosterone synthase inhibitors—yet make no mention of finasteride or any 5α-reductase inhibitor for hypertension treatment 1.
Finasteride's Actual Mechanism and Effects
Finasteride works by inhibiting the 5α-reductase type II enzyme, which converts testosterone to dihydrotestosterone (DHT), thereby reducing prostatic DHT by approximately 70% and causing a 15–25% reduction in prostate volume within 6 months 1, 2.
The drug's documented effects are confined to the prostate and include improved urinary symptom scores (average 3-point improvement on AUA/IPSS), reduced risk of acute urinary retention (67% reduction), and decreased need for BPH-related surgery (64% reduction) 1, 2, 3.
Finasteride's adverse effects are primarily sexual (decreased libido in 6.4%, ejaculatory dysfunction in 3.7% during the first year) and do not include cardiovascular effects such as hypotension or changes in blood pressure 1, 2.
Animal Research Does Not Translate to Human Blood Pressure Effects
One rat study found that finasteride decreased prostatic blood flow after 7 days of treatment, with no significant changes in systemic blood pressure or kidney blood flow 4.
This finding reflects local vascular changes within the prostate gland itself—not systemic blood pressure reduction—and has no clinical relevance to human hypertension management 4.
Cardiovascular Safety in Heart Failure
The European Society of Cardiology guidelines confirm that finasteride has no direct cardiovascular effects and does not interfere with cornerstone heart failure medications (ACE inhibitors, ARBs, beta-blockers, mineralocorticoid receptor antagonists, SGLT2 inhibitors) 5.
A 2019 retrospective study in heart failure patients found that finasteride was associated with reduced left ventricular hypertrophy (interventricular septal thickness 13.3 mm control vs. 12.6 mm finasteride, p=0.029), but this reflects anti-androgenic effects on cardiac remodeling rather than blood pressure lowering 6.
Common Pitfall to Avoid
Do not confuse alpha-blockers (e.g., doxazosin, terazosin) with 5α-reductase inhibitors (finasteride, dutasteride). Alpha-blockers used for BPH do lower blood pressure and can cause orthostatic hypotension, but finasteride does not share this property 1, 5, 3.
Patients with both hypertension and BPH require separate antihypertensive therapy; finasteride alone will not control blood pressure 5.