We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Prescription medication — not a dietary supplement
Vardenafil (Levitra)is a prescription (or investigational) drug, not a supplement. It is included here for reference because people research and discuss it (often used off-label) — not as a recommendation. Take it only under a qualified clinician's supervision and only as prescribed; do not source it from grey-market vendors, where identity, purity, and dosing are unverified. The evidence below reflects its clinical trials.
What the evidence says
Most Vardenafil (Levitra) studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality meta-analyses and randomised trials published 2001–2019.
Based on 6 studies · 1 meta-analysis · 4 RCTs
Confidence
ModerateBy outcome
Vardenafil (Levitra) has an evidence score of 3.6/10 — moderate evidence based on 6 indexed studies, including 1 meta-analysis. A potent, intermediate-acting PDE5 inhibitor (Levitra; Staxyn orodispersible tablet) for erectile dysfunction — the same drug class as sildenafil and tadalafil. It has a robust randomized-trial base for ED, including hard-to-treat populations like diabetes and post-prostatectomy. A prescription drug, not a supplement, and it carries a notable QT-prolongation caution on top of the class-wide nitrate contraindication. Representative study: PMID 30523399.
The commonly studied dose of Vardenafil (Levitra) is Approved on-demand ED dosing is 5-20 mg taken ~30-60 minutes before activity (10 mg typical start for the film-coated tablet); the orodispersible Staxyn tablet is 10 mg. Any use is clinician-directed and prescription-only; this is not a supplement regimen.. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
Nicotinamide Riboside
Mostly mechanism / observationalA vitamin B3 precursor that reliably raises cellular NAD+ levels and is well tolerated — but human trials have so far shown mostly null or mixed results on the functional outcomes (muscle, metabolism, blood pressure, cognition) that elevation is meant to drive.
MitoQ
Mostly mechanism / observationalLast reviewed June 2026 · evidence from 6 studies · how we score
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
Vardenafil (PDE5 inhibitor)
A potent, intermediate-acting PDE5 inhibitor (Levitra; Staxyn orodispersible tablet) for erectile dysfunction — the same drug class as sildenafil and tadalafil. It has a robust randomized-trial base for ED, including hard-to-treat populations like diabetes and post-prostatectomy. A prescription drug, not a supplement, and it carries a notable QT-prolongation caution on top of the class-wide nitrate contraindication.
Vardenafil has a strong, well-replicated RCT and meta-analytic base for erectile dysfunction, including efficacy in hard-to-treat populations (diabetes, post-radical-prostatectomy) — for that approved use the evidence is strong. The overall score is held below the top tier because it is a prescription-only drug rather than a supplement and because it carries a notable QT-prolongation caution on top of the class-wide nitrate contraindication.
Vardenafil is an oral phosphodiesterase-5 (PDE5) inhibitor marketed as Levitra (film-coated tablet) and Staxyn (orodispersible tablet, ODT) for erectile dysfunction.
Like sildenafil and tadalafil it works by blocking PDE5, which raises cyclic GMP and prolongs nitric-oxide-mediated relaxation of penile smooth muscle, enhancing erectile blood flow in response to sexual stimulation.
Vardenafil is highly potent, so it is dosed at low milligram amounts, and it sits between sildenafil and tadalafil on duration — a roughly 4-5 hour half-life with onset around 30-60 minutes that is blunted by high-fat meals.
The randomized-trial evidence for erectile dysfunction is robust: large double-blind, placebo-controlled trials (the first being Porst's at-home study) show dose-dependent, clinically meaningful improvement on the International Index of Erectile Function (IIEF), and the drug retains efficacy in difficult populations — men with diabetes and men with erectile dysfunction after radical prostatectomy — where erectile dysfunction is harder to treat.
Comparative and network meta-analyses place vardenafil among the effective, well-tolerated PDE5 inhibitors. Tolerability is generally good; the most common adverse effects are vasodilatory — headache, flushing, rhinitis (nasal congestion), and dyspepsia.
A distinguishing safety feature is that vardenafil’s labeling carries a specific QT-prolongation precaution that the other PDE5 inhibitors’ labels do not, so it should be avoided in men with congenital long-QT syndrome and in those taking Class IA or Class III antiarrhythmics or other QT-prolonging drugs.
As with the entire class, vardenafil is absolutely contraindicated with nitrates in any form, because the combination can cause severe, potentially fatal hypotension; it requires caution with alpha-blockers and other antihypertensives, and shares the rare but serious class risks of priapism, non-arteritic anterior ischemic optic neuropathy (NAION), and sudden hearing loss.
This is an informational entry on a prescription medication used under clinician supervision — not a supplement and not a recommendation. The score reflects strong, well-replicated efficacy for erectile dysfunction held below the top tier by the prescription-only status and the added QT-prolongation caution.
Vardenafil potently blocks PDE5, raising cyclic GMP and prolonging nitric-oxide-mediated smooth-muscle relaxation — the basis for its erectile effect.
Enhanced NO/cGMP signaling relaxes penile smooth muscle and increases blood flow in response to sexual stimulation, improving erectile function.
Vardenafil modestly prolongs the QT/QTc interval; a head-to-head study found the effect small and comparable to sildenafil, but its labeling still carries a specific QT precaution underlying its caution with antiarrhythmics and other QT-prolonging drugs.
How Vardenafil (Levitra) works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Tap node to isolate • Pinch to zoom • Tap edge for research
Approved on-demand ED dosing is 5-20 mg taken ~30-60 minutes before activity (10 mg typical start for the film-coated tablet); the orodispersible Staxyn tablet is 10 mg. Any use is clinician-directed and prescription-only; this is not a supplement regimen.
Can be taken without food
| Form | Type |
|---|---|
| 💊Oral film-coated tablet (vardenafil HCl) | Recommended |
| 💊Staxyn orodispersible tablet (vardenafil ODT) | Alternative |
| 💊Sildenafil (short-acting PDE5 inhibitor) | Alternative |
| 💊Tadalafil (long-acting PDE5 inhibitor) | Alternative |
Vardenafil's intermediate half-life suits on-demand use; the ODT formulation is not dose-equivalent to the film-coated tablet.
Compare Vardenafil (Levitra) vs Sildenafil (Viagra) →Minimum: 1 weeks
Optimal: 12 weeks
Cycling: Not required
Note: Intermediate-acting and on-demand for ED (onset ~30-60 min, slowed by high-fat meals). Never combine with nitrates; avoid with QT-prolonging antiarrhythmics.
Dose-response data unavailable. The current published research for Vardenafil (Levitra) does not provide sufficient dose-specific outcome data to generate reliable dose-response curves.
Refer to the Dosage & Timing section above for recommended dose ranges based on available evidence.
Robust RCT and meta-analytic evidence for dose-dependent, clinically meaningful improvement in erectile function (IIEF) versus placebo.
Randomized trials show efficacy in men with diabetes and in men with erectile dysfunction after radical prostatectomy — settings where ED is harder to treat.
Common vasodilatory effects — headache, flushing, nasal congestion (rhinitis), and dyspepsia; usually mild and transient.
Vardenafil’s labeling carries a specific QT-prolongation precaution — avoid in congenital long-QT syndrome and with Class IA/III antiarrhythmics or other QT-prolonging drugs.
Combined with nitrates in any form it causes severe, potentially fatal hypotension — an absolute contraindication; caution with alpha-blockers.
Absolute contraindication — dangerous hypotension.
Avoid — vardenafil’s labeling carries a specific QT-prolongation precaution.
Avoid until cleared by a clinician.
Use low starting doses and monitor blood pressure.
Discuss the rare risk of optic-nerve injury with a clinician before use.
Combined PDE5 inhibitor + nitrate causes severe, potentially fatal hypotension — an absolute contraindication.
Vardenafil carries a specific QT-prolongation precaution in its labeling; combining with antiarrhythmics (e.g. quinidine, procainamide, amiodarone, sotalol) or other QT-prolonging agents raises arrhythmia risk — avoid.
Tip: Vasodilatory; usually mild and transient.
Tip: Class/dose-related; generally transient.
Tip: Avoid in long-QT syndrome and with antiarrhythmics/QT-prolonging drugs; clinician assessment for at-risk patients.
Tip: Seek urgent care; avoid nitrates; an erection lasting >4 hours is a medical emergency.
Timing is flexible for Vardenafil (Levitra) — consistent daily use matters more than the time of day. Intermediate-acting; onset ~30-60 minutes and a high-fat meal slows/blunts absorption, so it is often taken on a relatively empty stomach.
Vardenafil (Levitra) is generally safe at recommended doses, with a few precautions worth noting. The most commonly reported side effects are headache / flushing, rhinitis (nasal congestion) / dyspepsia, qT-interval prolongation. Use caution if any of these apply to you: Concurrent nitrates (any form); Congenital long-QT syndrome or concurrent Class IA/III antiarrhythmics or other QT-prolonging drugs; Recent cardiovascular event / unstable angina.
A mitochondria-targeted antioxidant — CoQ10 conjugated to a triphenylphosphonium (TPP+) cation so it accumulates several-hundred-fold inside mitochondria. Sold OTC as a supplement. Its best human signal is improved endothelial/vascular function in older adults (one small RCT); several trials are null (Parkinson's, exercise adaptation), and almost all outcomes are surrogate/biomarker, not hard clinical endpoints.
Additive blood-pressure lowering — use caution and lower starting doses.
Raise vardenafil levels (e.g. ritonavir, ketoconazole, itraconazole); dose reduction or avoidance advised.