Viagra® Tablets for Erectile Dysfunction (Sildenafil)

What Viagra® Is and How It Works

Viagra® (sildenafil) is an oral phosphodiesterase type 5 (PDE5) inhibitor used to treat erectile dysfunction (ED) in adult men. It supports erectile response by enhancing nitric oxide–mediated vasodilation in penile tissue during sexual stimulation. The medicine does not increase desire and requires sexual arousal to work. Many people search for a reliable viagra pill or viagra tablet for on‑demand use, and this option has decades of clinical experience.

CanadianInsulin is a prescription referral service. Prescriptions are verified with your clinic, and orders are filled by licensed Canadian pharmacies.

After a dose, onset typically occurs within 30 to 60 minutes, and food—especially a high‑fat meal—may delay the effect. The terminal half‑life is about 4 hours. Sildenafil is also available as a generic, which offers a cost‑effective alternative to brand Viagra. For ED, common strengths include 25 mg, 50 mg, and 100 mg. The 20 mg strength is often used for pulmonary arterial hypertension under other brand names, not as standard ED dosing.

Viagra works by selectively blocking PDE5 in the corpus cavernosum. This maintains cyclic GMP levels, relaxes smooth muscle, and improves blood flow. It should not be used with nitrates or riociguat due to the risk of severe hypotension. Caution is needed with alpha‑blockers and certain CYP3A4 inhibitors. For more background on ED, see our Erectile Dysfunction page and the article Uncovering The Link Between Diabetes And Erectile Dysfunction.

Dosage and Usage

The information below summarizes typical use. Follow the prescribing clinician’s instructions on dose and timing.

• Initiation: Many adults start at 50 mg taken about 1 hour before sexual activity.
• Titration: Adjust to 25 mg or 100 mg based on efficacy and tolerability.
• Frequency: Do not take more than once per day.
• With/without food: May be taken with or without food; high‑fat meals can delay onset.
• Timing: Some patients respond as early as 30 minutes; allow adequate time before sexual activity.
• Interactions: Do not use with nitrates or riociguat; use caution with alpha‑blockers and potent CYP3A4 inhibitors.
• Alcohol: Limit intake; alcohol can worsen dizziness and reduce erectile response.
• Missed dose: On‑demand dosing; there is no daily schedule to make up.

Storage and travel

• Store tablets at 20–25°C (68–77°F); allowable excursions 15–30°C (59–86°F).
• Keep in the original, tightly closed container; protect from moisture and light.
• Keep out of reach of children and pets.
• When traveling, keep tablets in carry‑on baggage with the prescription label.
• Avoid leaving medicine in hot cars or freezing environments.
• Bring enough supply for the trip, plus a small buffer.

Benefits and Savings

Viagra improves erectile function and sexual confidence in many men with ED. On‑demand dosing offers flexibility, with a range of strengths to match individual response. The well‑studied safety profile and predictable onset make it a trusted option for occasional use. For some, generic sildenafil offers similar clinical results at a lower out‑of‑pocket cost.

Orders are dispensed through licensed, vetted partner pharmacies with authentic brand medications, a broad selection, and value‑focused pricing. Many customers save 60–80% vs typical U.S. prices. See our promotions page for current offers, including any viagra for sale if available.

Side Effects and Safety

Common effects are usually mild and temporary. If side effects persist or worsen, contact a healthcare professional.

• Headache, facial flushing, warmth
• Indigestion, nausea, abdominal discomfort
• Nasal congestion, runny nose
• Dizziness or lightheadedness
• Back pain or muscle aches
• Visual changes (color tinge, blurred vision, sensitivity to light)

Serious but rare risks include priapism (painful erection lasting more than 4 hours), sudden vision loss due to non‑arteritic anterior ischemic optic neuropathy (NAION), sudden hearing loss or ringing, severe allergic reactions, and significant drops in blood pressure. Do not use with nitrates (for chest pain) or riociguat. Use caution with alpha‑blockers, other antihypertensives, and strong CYP3A4 inhibitors. Avoid combining PDE5 inhibitors within the same dosing window.

Onset Time

Most patients notice benefits in 30 to 60 minutes when taken on an empty stomach. A high‑fat meal may push onset closer to 60–120 minutes. Peak effect is often within 1–2 hours, and the response can last about 4 hours, sometimes longer. Consistent, reliable results may improve after several uses once the right dose and timing are identified with the prescriber.

Compare With Alternatives

Cialis® (tadalafil) is another PDE5 inhibitor with a longer half‑life. Many prefer its 24–36 hour window for greater spontaneity, and a daily low‑dose option may suit those with frequent sexual activity or concomitant BPH symptoms. Compare cialis with sildenafil and discuss which profile fits the intended use.

Levitra® (vardenafil) is similar to sildenafil in duration and onset. It may have slightly different food effects and side‑effect patterns. Patients often weigh onset time, duration, side effects, and cost when choosing between sildenafil and tadalafil or vardenafil.

Combination Therapy

• PDE5 inhibitor monotherapy is standard for ED management.
• Consider evaluation and treatment of hypogonadism; testosterone therapy may be used when clinically appropriate.
• Optimize cardiovascular risk factors and address lifestyle contributors through medical care.
• Do not combine with nitrates or riociguat; risk of severe hypotension.
• Use caution with alpha‑blockers; dose adjustments and staggered timing may reduce hypotension.
• Review antihypertensive regimens since additive blood pressure lowering can occur.

Patient Suitability and Cost‑Saving Tips

Candidates include adult men with ED seeking on‑demand treatment. It is not indicated for women or children. A lower starting dose may be considered in older adults or those with hepatic or renal impairment. Patients with certain eye disorders, significant cardiovascular disease, or anatomical penile deformities require careful evaluation.

Do not use if taking nitrates for chest pain or riociguat. Caution is advised in recent myocardial infarction or stroke, severe hypotension or uncontrolled hypertension, unstable angina, severe liver disease, or conditions that predispose to priapism (e.g., sickle cell disease, leukemia, multiple myeloma). Discuss all medicines and supplements to screen for interactions.

Cost‑saving ideas include choosing generic sildenafil when appropriate, comparing strengths to match the effective dose, and considering multi‑month quantities to reduce per‑tablet costs. Set simple reorder reminders to avoid last‑minute purchases. For patients exploring broader health factors that affect sexual function, related reading is available under Does Diabetes Affect Fertility and Type 2 Diabetes Complications.

Authoritative Sources

Pfizer manufacturer information for Viagra

Health Canada Product Monograph (sildenafil)

U.S. FDA Prescribing Information and Medication Guide

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This page is educational and does not replace professional medical advice. Always speak with a qualified healthcare provider about diagnosis, treatment choices, and medication risks.