Sildenafil 20 mg 25 mg 50 mg 100 mg

What is Sildenafil?

Sildenafil is a prescription medicine used to treat erectile dysfunction (ED) in men and certain cases of pulmonary arterial hypertension (PAH) in adults. In ED, it improves blood flow to the penis to help achieve and maintain an erection when combined with sexual stimulation. In PAH, it relaxes blood vessels in the lungs to reduce blood pressure and improve exercise capacity.

Sildenafil is available in 20 mg, 25 mg, 50 mg, and 100 mg tablets. The 20 mg form is commonly used for PAH, while the higher strengths are usually prescribed for ED. Because generic sildenafil is widely available, many people compare prices for cheap options or buy it online from licensed U.S. pharmacies. Always ensure the medicine is authentic, with correct labeling, strength, and expiration date.

How It Works

Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor. It works by blocking the PDE5 enzyme, which increases levels of cyclic GMP in smooth muscle cells. This relaxes blood vessels, improving blood flow to the penis for ED or lowering blood pressure in the lungs for PAH. For ED, sexual stimulation is required for the medicine to be effective.

What you may notice

In ED treatment, improved ability to get and keep an erection during sexual activity. In PAH treatment, improved ability to walk longer distances and less shortness of breath over time.

Dosage Information

The dose depends on the condition being treated and individual patient factors. Always follow your clinician’s instructions.

• For ED: Typical starting dose is 50 mg taken about 1 hour before sex. May be adjusted to 25 mg or 100 mg based on effectiveness and tolerability. Do not take more than once daily.
• For PAH: 20 mg three times daily, taken about 4 to 6 hours apart.

How to take it

Swallow the tablet whole with water. For ED, it may be taken with or without food, but a high fat meal can delay the effect. For PAH, take doses at evenly spaced intervals each day.

Cost and access tips

Generic sildenafil is less expensive than brand name products. Buying from licensed online pharmacies can lower cost. Cheap pricing is fine when labeling and expiration dates are clear, and a pharmacist is available for questions.

Side Effects

Common side effects include headache, flushing, nasal congestion, indigestion, dizziness, and vision changes. These are generally mild and temporary.

Less common but important

• Priapism: An erection lasting more than 4 hours requires urgent care.
• Sudden vision or hearing loss: Stop the medicine and seek immediate medical attention.
• Low blood pressure: More likely in people taking nitrates or certain blood pressure medicines.

Warnings & Interactions

Sildenafil should not be used with nitrates (such as nitroglycerin) or guanylate cyclase stimulators (such as riociguat), as the combination can cause dangerously low blood pressure. Use with caution in people with heart disease, recent heart attack or stroke, severe liver or kidney disease, or certain eye conditions.

Drug interactions

• Nitrates: Dangerous drop in blood pressure when combined.
• Alpha blockers: May cause dizziness or fainting from low blood pressure.
• Strong CYP3A4 inhibitors: Such as ketoconazole, itraconazole, or ritonavir, can increase sildenafil levels.

Practical safety tips

Only take sildenafil as prescribed. For ED, sexual stimulation is necessary for it to work. If buying online, choose licensed U.S. pharmacies, check labeling and expiration dates, and ensure the product is genuine. Cheap pricing is acceptable when those checks are met.