Nizagara (Sildenafil Citrate) – Clinical Overview, Dosage, Safety and Medical Information

Last medically reviewed: 2026-02-14

Nizagara is a branded formulation of sildenafil citrate used in the treatment of erectile dysfunction (ED). Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor and is the same active ingredient used in brand-name Viagra. The clinical and safety information on this page is based on established evidence and prescribing information for sildenafil citrate.

Availability, labeling, and regulatory status of Nizagara may vary by country and pharmacy provider. This page is intended for informational purposes and does not replace medical advice.

Indication

Nizagara (sildenafil citrate) is used to treat erectile dysfunction in adult men. Erectile dysfunction is the inability to achieve or maintain an erection sufficient for satisfactory sexual performance.

Sildenafil works only with sexual stimulation and does not increase libido.

About Nizagara

Nizagara is marketed as a sildenafil-based alternative to brand-name sildenafil products. It may be available in different strengths (commonly 25 mg, 50 mg, and 100 mg). Manufacturing and packaging details can differ by market.

Mechanism of Action

Sildenafil inhibits phosphodiesterase type 5 (PDE5). During sexual stimulation, nitric oxide (NO) is released in the corpus cavernosum and increases cyclic guanosine monophosphate (cGMP). By reducing cGMP breakdown, sildenafil enhances smooth muscle relaxation and can increase blood flow in penile tissue.

Dosage and Administration

Prescribing information for sildenafil products commonly recommends a starting dose of 50 mg taken approximately 30–60 minutes before sexual activity. Depending on effectiveness and tolerability, the dose may be reduced to 25 mg or increased to 100 mg.

Do not take more than one dose within 24 hours unless directed by a healthcare professional.

Common Tablet Strengths

Common Nizagara tablet strengths

Product	Active Ingredient	Form	Strength
Nizagara	Sildenafil citrate	Tablet	25 mg
Nizagara	Sildenafil citrate	Tablet	50 mg
Nizagara	Sildenafil citrate	Tablet	100 mg

Onset and Duration

Sildenafil typically begins to work within 30 to 60 minutes. Duration of effect may last up to approximately 4 hours, though individual response varies. High-fat meals may delay the onset of action.

Contraindications

Nizagara (sildenafil) must not be used with nitrates (e.g., nitroglycerin, isosorbide dinitrate/mononitrate) because the combination may cause a dangerous drop in blood pressure.

It is also contraindicated with nitric oxide donors and recreational “poppers” (amyl nitrite).

Warnings and Precautions

• Recent myocardial infarction or stroke
• Severe cardiovascular disease or unstable angina
• Uncontrolled hypotension or hypertension
• Severe hepatic impairment
• Inherited retinal disorders such as retinitis pigmentosa

Erectile dysfunction may be associated with underlying cardiovascular or metabolic disease. Clinical evaluation is recommended before initiating therapy.

Adverse Reactions

Common adverse effects associated with sildenafil include headache, flushing, dyspepsia, nasal congestion, dizziness, and visual disturbances.

Seek urgent medical care for chest pain, sudden vision loss, sudden hearing decrease, or an erection lasting more than four hours (priapism).

Drug Interactions

Sildenafil may interact with:

• Nitrates and nitric oxide donors
• Alpha-blockers
• Strong CYP3A4 inhibitors (e.g., certain antifungals and antivirals)
• Some antibiotics
• Other medications for erectile dysfunction (avoid combination unless medically supervised)

Always disclose all medications and supplements to a healthcare professional.

Clinical Evidence

Direct clinical trial data for a specific brand may vary by market. In general, evidence supporting the effectiveness and safety profile of Nizagara is derived from established randomized controlled trials and prescribing information for sildenafil citrate.

Sources

• U.S. Food and Drug Administration — Viagra (sildenafil) Prescribing Information.
• European Medicines Agency (EMA) — Viagra EPAR.
• EMA — Product Information (SmPC).
• NIH / PubMed Central — Review of sildenafil in erectile dysfunction.
• PubMed — Sildenafil: a review of its use in erectile dysfunction.

Medical Disclaimer

This content is provided for informational purposes only and does not constitute medical advice. Always consult a licensed healthcare professional before starting or changing medication.