There is no single “best” medicine for erectile dysfunction because the four main prescription options work through the same mechanism and have similar success rates. About 65 to 70% of men respond well to these medications. The real differences come down to how fast they kick in, how long they last, and how they fit into your life. Understanding those practical details will help you and your doctor pick the right one.
How ED Medications Work
All four major prescription pills belong to the same drug class. They work by relaxing blood vessels in the penis, which allows more blood flow when you’re sexually aroused. They don’t create arousal on their own, and they won’t work without stimulation. The drugs differ mainly in their timing: how quickly they start working and how long the window of effectiveness stays open.
A systematic review published in JAMA Internal Medicine found that 78% of men using sildenafil reported improved erections in flexible-dose trials, compared to 25% on placebo. The other medications in this class perform in a similar range. That said, roughly 30 to 35% of men don’t respond to any of these pills, which is why other treatment options exist.
Sildenafil: The Most Widely Used Option
Sildenafil, originally sold as Viagra, is the most familiar ED medication and now one of the most affordable. It’s taken about an hour before sex, and its effects typically last four to six hours. Doses range from 25 mg to 100 mg, with most men starting at 50 mg and adjusting from there.
Because sildenafil has been available the longest, its generic versions are competitively priced. Generic sildenafil can cost as little as $2 per pill, though prices vary widely by pharmacy. With a discount card, six pills of 100 mg generic sildenafil range from about $9 to $97 depending on where you fill the prescription. For comparison, brand-name Viagra averages around $70 per pill. One downside: fatty meals can delay absorption and reduce effectiveness, so timing around dinner can be tricky.
Tadalafil: The Longest-Lasting Option
Tadalafil, the generic form of Cialis, stands out because its effects last up to 36 hours. That extended window is why it’s sometimes called the “weekend pill.” It’s taken about an hour before sex at doses of 10 mg or 20 mg, and food doesn’t significantly affect how well it works.
Tadalafil also comes in a daily low-dose version (2.5 mg or 5 mg) that stays active around the clock. According to Harvard Health Publishing, a daily pill lets you have sex at any time without planning around a dose. The trade-off: daily dosing may reduce side effects for some men, but it can also be slightly less effective than the higher on-demand dose. The 36-hour window of the as-needed version often provides enough flexibility without committing to a daily pill.
Generic tadalafil in daily 5 mg doses runs about $10 to $34 for ten tablets with a discount card. Higher on-demand doses (10 mg or 20 mg) start around $21 for ten pills. If you’re having sex two or more times a week, the daily version may end up being more convenient and cost-effective.
Vardenafil: Similar to Sildenafil
Vardenafil (generic Levitra) works on a similar timeline to sildenafil. It’s taken about an hour before sex at 10 mg or 20 mg. Its effects last roughly four to six hours. Some men who experience side effects with sildenafil find that vardenafil works better for them, even though the drugs are closely related. Like sildenafil, high-fat meals can interfere with absorption.
Avanafil: The Fastest to Start Working
Avanafil (Stendra) is the newest of the four and has the quickest onset. In clinical studies, successful intercourse was observed as early as 15 minutes after taking it. Out of 300 sexual attempts made within 15 minutes of dosing, 64 to 71% were successful with avanafil compared to 27% with placebo. Peak response occurs within 20 to 40 minutes, compared to 60 to 80 minutes for sildenafil.
That speed advantage makes avanafil appealing for men who want less planning. It also tends to produce fewer side effects because it’s more selective in which blood vessels it targets. The main drawback is cost: avanafil is newer, so generic options are limited and the price per pill is higher than sildenafil or tadalafil.
Choosing Based on Your Lifestyle
The American Urological Association doesn’t rank one medication above another. Its guidelines emphasize that all treatment options should be discussed, and the choice should be based on what fits your situation. In practice, the decision often comes down to a few lifestyle questions:
- How often do you have sex? If it’s several times a week, daily tadalafil removes the need to plan around a pill. If it’s once a week or less, an on-demand option makes more sense financially.
- How important is spontaneity? Tadalafil’s 36-hour window or daily dosing offers the most flexibility. Avanafil’s 15-minute onset is the next best thing.
- Does cost matter? Generic sildenafil is the cheapest option by a wide margin. Generic tadalafil is also affordable. Avanafil and brand-name versions cost significantly more.
- Do you take nitrate medications? This is a hard stop for all four drugs, not a preference issue. Combining any of them with nitrates (commonly prescribed for chest pain) can cause a dangerous drop in blood pressure. With tadalafil specifically, the interaction with nitroglycerin lasts at least 24 hours after a dose.
Most doctors start with sildenafil or tadalafil simply because they’re well-studied, effective, and affordable. If one doesn’t work or causes bothersome side effects like headaches, flushing, or nasal congestion, switching to a different one often helps. The medications are similar enough that failure with one doesn’t predict failure with another.
Over-the-Counter Topical Gel
In 2023, the FDA cleared an over-the-counter topical gel called MED3000 (sold as Eroxon). It works differently from prescription pills. Instead of affecting blood vessels throughout the body, it’s applied directly to the tip of the penis and works within minutes. Clinical trials showed significant improvements in erectile function across different severities of ED, with a rapid onset and fewer side effects than oral medications. It’s a reasonable option for men with mild ED who want to avoid prescription pills, though it’s generally less effective for moderate to severe cases.
Supplements: What the Evidence Shows
L-arginine is the most studied supplement for ED. A meta-analysis found that doses between 1,500 and 5,000 mg per day significantly improved erectile function compared to placebo, with about three times the odds of improvement. Scores for overall satisfaction, orgasmic function, and intercourse satisfaction also improved. Side effects were mild and occurred in about 8% of users.
The catch: these benefits were most consistent in men with mild to moderate ED. L-arginine is not a replacement for prescription medication in more severe cases. Many other supplements marketed for ED, including most “male enhancement” products, lack reliable clinical evidence and may contain undisclosed pharmaceutical ingredients.
When Pills Don’t Work
For the roughly one-third of men who don’t respond to oral medications, other options exist. These include injectable medications delivered directly into the penis (more effective than pills for many men), vacuum erection devices, and penile implants for severe cases. The underlying cause also matters. ED tied to low testosterone may improve with hormone therapy. ED caused by psychological factors like performance anxiety or depression often responds well to therapy, sometimes in combination with medication.
ED can also be an early warning sign of cardiovascular disease, since the same blood vessel problems that restrict flow to the penis can affect the heart. Men who develop ED, especially before age 50 and without an obvious cause, benefit from a cardiovascular checkup even if the ED itself responds to medication.