Does Levitra Affect Blood Testosterone Levels?
No, Levitra (vardenafil) does not alter blood testosterone levels when used for erectile dysfunction treatment. The available evidence demonstrates that PDE-5 inhibitors like vardenafil work through a completely different mechanism—enhancing nitric oxide-mediated vasodilation—and do not interfere with hormonal pathways or testosterone measurement 1.
Mechanism and Evidence
Vardenafil functions as a selective phosphodiesterase type 5 (PDE5) inhibitor, improving erectile function by enhancing nitric oxide-mediated relaxation in penile tissue, not by altering testosterone production or metabolism 2.
Clinical guidelines from the American College of Physicians explicitly distinguish between PDE-5 inhibitor therapy and hormonal treatment, recommending PDE-5 inhibitors as first-line therapy regardless of testosterone status 1.
Studies evaluating vardenafil in combination with testosterone therapy measured both parameters independently, confirming that vardenafil does not affect testosterone levels while testosterone supplementation does increase testosterone (as expected) 3, 4, 5.
Clinical Context: When Both Are Relevant
While vardenafil doesn't change testosterone levels, understanding their relationship matters clinically:
In hypogonadal men with erectile dysfunction who fail testosterone monotherapy, adding vardenafil improves erectile function without further altering testosterone levels 5. In this study of 129 testosterone-deficient patients, those who didn't respond to testosterone alone (51 patients) were given vardenafil 20 mg on demand—30 of 34 responders showed improved erectile function while testosterone levels remained at the corrected range achieved by testosterone therapy alone.
Chronic vardenafil use (10 mg twice daily for 24 weeks) in diabetic men with erectile dysfunction actually increased testosterone levels in hypogonadal patients, but this appears to be an indirect effect through improved endothelial function rather than direct hormonal manipulation 3. Importantly, gonadotropins remained unchanged, suggesting the mechanism is not through the hypothalamic-pituitary-gonadal axis.
Laboratory Testing Implications
You can safely measure testosterone levels in patients taking vardenafil without concern for interference. The drug will not falsely elevate or suppress testosterone results 1.
The American College of Physicians notes that routine hormonal testing in erectile dysfunction has insufficient evidence for universal recommendation, but when clinically indicated (decreased libido, fatigue, testicular atrophy), vardenafil use does not preclude accurate testosterone measurement 1.
Key Clinical Pitfall
The main error to avoid is assuming that because vardenafil treats erectile dysfunction, it must affect testosterone. These are separate therapeutic pathways: vardenafil enhances the downstream effects of nitric oxide on smooth muscle, while testosterone affects libido, central arousal mechanisms, and potentially endothelial health through different mechanisms 1, 2.