Levitra 20mg is a prescription medication containing vardenafil hydrochloride, a phosphodiesterase type 5 (PDE5) inhibitor used primarily to treat erectile dysfunction (ED) in adult men. The 20mg dose is the maximum recommended strength per tablet. It’s not for women, children, or recreational use.

How It Works

• Vardenafil increases blood flow to the penis by relaxing smooth muscles and dilating blood vessels during sexual stimulation.
• It does not cause an erection without arousal and does not protect against STDs or increase fertility.
• Effects typically start in 25-60 minutes, peak at 30-120 minutes, and last 4-5 hours (up to 8 in some cases).

Evidence: Clinical trials (e.g., FDA approval data from 2003 and studies in The Journal of Sexual Medicine) show 20mg vardenafil improves erections in 65-80% of men with ED, outperforming placebo (30-40%). It’s effective even after food/alcohol (unlike some PDE5 inhibitors).

Dosage Guidelines

• Do not exceed 20mg/day. Lower to 5-10mg if you have liver/kidney issues, are over 65, or take certain meds.

Common Side Effects (Affecting 1-10% of users)

Evidence: From Bayer/GSK post-marketing data and meta-analyses (European Urology, 2018) showing low discontinuation rates (<2%) due to sides.

Key Warnings & Contraindications

• Never take with nitrates (e.g., nitroglycerin for chest pain) → life-threatening blood pressure drop.
• Avoid if you have severe heart/liver/kidney disease, recent stroke/heart attack, low BP, or eye conditions like retinitis pigmentosa.
• Drug interactions: Alpha-blockers, antifungals (ketoconazole), HIV protease inhibitors, erythromycin → dose adjustment needed.
• Alcohol: Limit to 3 drinks; excess increases dizziness/fainting risk.
• Not for: Pulmonary hypertension (use specific formulations) or female use.

Evidence: FDA black box warning on nitrates; confirmed in trials where combo caused 50mmHg BP drops.

Availability & Cost

• Prescription only (Schedule not controlled in most countries).
• Generic vardenafil available since 2018, cheaper than brand (~20+).
• Buy from licensed pharmacies; avoid unverified online sources (risk of fakes per FDA alerts).

Consult a doctor before use—especially with health conditions or meds. This is general info, not personalized advice. For full details, see official sources like FDA Label or EMA Summary. If experiencing ED, underlying causes (e.g., diabetes, stress) should be addressed.