Viagra is still the world’s most popular ED treatment because it consistently works for most men, has over 25 years of proven safety data, and provides results within 30 to 60 minutes that can last up to 4 hours.
When you take Viagra (sildenafil), it increases blood flow to the penis by relaxing blood vessels, which helps you achieve and maintain an erection when sexually stimulated. Its reliability is one of the biggest reasons why millions of men worldwide continue to use it. Clinical studies show that Viagra works effectively in about 70–80% of men with erectile dysfunction, making it one of the most trusted options available.
You may also feel more confident using Viagra because it has a strong safety record since its approval by the FDA in 1998. Unlike many newer ED treatments, Viagra has been tested extensively and is prescribed globally under strict medical guidelines. The medication starts working in as little as half an hour for most people, and its effects last long enough to enjoy planned intimacy without feeling rushed.
Another reason Viagra stays popular is its wide availability; you can get it in branded and generic forms, often at different price points, which makes it accessible. With decades of patient success stories, ongoing trust from doctors, and consistent effectiveness, Viagra remains the first choice for many men dealing with ED.
How Does Viagra’s Onset and Duration Compare with Cialis for Me?
Viagra usually starts working for you in 30 to 60 minutes and lasts up to 4 hours, while Cialis takes about 30 to 45 minutes but can stay effective for up to 36 hours.
When you take Viagra (sildenafil), it begins working in about half an hour, with peak effects around the 1-hour mark. Its active window is about 4 hours, which means you’ll need to plan intimacy within that time frame. For many men, Viagra provides a fast and reliable effect, but the short duration requires more timing.
Cialis (tadalafil), on the other hand, has a slightly slower onset, usually 30 to 45 minutes, but it’s unique because it lasts much longer, up to 36 hours. This extended duration is why Cialis is often called the “weekend pill.” For you, this means more flexibility and less pressure to schedule intimacy. Cialis also comes in a daily low-dose option, which maintains steady levels in your body and lets you stay ready anytime, without waiting for a dose to kick in.
So, if you prefer quick, short-term results, Viagra may suit you better. But if you want longer coverage and spontaneity, Cialis could be the more convenient choice.
What Long-Term Risks Should I Consider if I Use Viagra Chronically?
If you use Viagra chronically, the main long-term risks to consider are cardiovascular strain, potential vision or hearing issues, drug interactions, and psychological dependence, though serious complications are uncommon when used under medical supervision.
When you take Viagra (sildenafil) regularly over many years, most studies show it remains generally safe for men without major underlying health problems. Still, there are a few important risks you should keep in mind:
Cardiovascular effects
Viagra works by dilating blood vessels, which can lower blood pressure. If you already take nitrates or certain heart medications, the combination can cause dangerously low blood pressure. Chronic use may also place stress on your heart if you have untreated cardiovascular disease.
Vision and Hearing Problems
Rarely, long-term use has been linked to retinal changes (such as non-arteritic anterior ischemic optic neuropathy, NAION) or sudden hearing loss. These side effects are uncommon but can be serious.
Psychological Dependence
While Viagra is not physically addictive, you might start to feel reliant on it for sexual confidence, even when you may not always need it. Over time, this can affect your natural sexual response or self-esteem.
Underlying Health Masking
Chronic ED can be a symptom of conditions like diabetes, hypertension, or vascular disease. Relying on Viagra without addressing these root causes could delay important medical care.
Tolerance and Dose Adjustment
Some men report needing higher doses over time, though clinical evidence on tolerance is mixed. Higher doses can increase the chance of side effects like headaches, flushing, or indigestion.
Why Does Viagra Cause Vision Changes More Often than Other PDE5 Inhibitors?
Viagra (sildenafil) is more likely to cause vision changes than other PDE5 inhibitors because it not only blocks the PDE5 enzyme in the penis but also partially blocks PDE6, an enzyme in the retina that helps your eyes process light.
When you take Viagra, its main job is to inhibit PDE5, which increases blood flow to help with erections. But sildenafil also has a measurable effect on PDE6, which is found in the light-sensitive cells of your retina. This off-target action can temporarily alter how your eyes perceive color and light. That’s why you may notice a blue-green tint, blurred vision, or increased sensitivity to light after using Viagra.
Other PDE5 inhibitors like Cialis (tadalafil) and Levitra (vardenafil) are more selective for PDE5 and have very little impact on PDE6. Because of this, they cause fewer vision-related side effects. For example:
Cialis (tadalafil): Highly selective for PDE5 → very rare vision changes.
Levitra (vardenafil): Slight PDE6 effect, but less than Viagra → lower chance of vision issues.
Viagra (sildenafil): Noticeable PDE6 inhibition → higher likelihood of temporary vision changes.
For most men, these effects are short-lived and mild, resolving as the drug leaves the body. However, in rare cases, long-term or sudden vision loss (such as NAION – non-arteritic anterior ischemic optic neuropathy) has been reported, especially in people with risk factors like diabetes, high blood pressure, or existing eye disease.