ED medication refers to any drug or treatment used to help men achieve or maintain an erection firm enough for sex. The most common type is a class of oral pills called PDE5 inhibitors, which includes well-known names like Viagra and Cialis. These medications work by increasing blood flow to the penis, and they’re effective for roughly 60 to 70 percent of men who try them. Beyond pills, there are also injectable treatments, urethral suppositories, and a newer over-the-counter topical gel.
How ED Medications Work
When a man becomes sexually aroused, nerves and blood vessel cells in the penis release a chemical called nitric oxide. This triggers a chain reaction: nitric oxide activates an enzyme that produces a second messenger molecule called cGMP, which relaxes the smooth muscle in penile arteries and allows blood to flow in. The erection lasts as long as cGMP levels stay elevated.
The body naturally breaks down cGMP using an enzyme called PDE5. In men with erectile dysfunction, this breakdown happens too quickly or blood flow is already compromised, so the erection doesn’t form or fades too soon. PDE5 inhibitors block that cleanup enzyme, letting cGMP accumulate and keeping the arteries relaxed longer. The key point: these medications don’t create arousal on their own. Sexual stimulation is still needed to start the nitric oxide release in the first place.
The Four FDA-Approved Oral Medications
Four PDE5 inhibitors are approved in the United States. They all work through the same basic mechanism but differ in how quickly they kick in and how long they last.
- Sildenafil (Viagra): The original, approved in 1998. It starts working in about 30 minutes and lasts 4 to 8 hours. A high-fat meal can delay absorption, so it’s best taken on a lighter stomach. The typical starting dose is 50 mg, with a range of 25 to 100 mg.
- Tadalafil (Cialis): Known for its long duration, lasting anywhere from 17.5 to 36 hours, which is why it’s sometimes called “the weekend pill.” It also kicks in around 30 minutes and can be taken with or without food. The starting dose is 10 mg for as-needed use, with a maximum of 20 mg. A lower daily dose of 2.5 or 5 mg is also available for men who prefer continuous coverage.
- Vardenafil (Levitra): Similar in onset and duration to sildenafil, with a slightly different chemical structure that may work better for some men who don’t respond to other options.
- Avanafil (Stendra): The newest oral option, designed to work faster, sometimes in as little as 15 minutes. It also tends to have fewer side effects because it’s more selective in targeting the PDE5 enzyme.
How Effective Are They?
PDE5 inhibitors work well for the majority of men, but they’re not guaranteed. Clinical data shows that about 30 to 40 percent of patients either don’t respond or aren’t satisfied with on-demand treatment. Results also depend on the underlying cause of the ED. Men with diabetes, nerve damage from surgery, or severe cardiovascular disease tend to have lower response rates than men whose ED is primarily related to stress or mild blood flow issues.
For tadalafil taken daily at 5 mg, clinical trials found that 55 percent of men achieved successful intercourse on their first attempt, compared to about 29 percent on placebo. After an initial success, the rate on subsequent attempts climbed to nearly 86 percent. One particularly interesting finding: among men who took daily tadalafil for a year and then stopped, about 46 percent still showed improvement over their original baseline after a four-week break, suggesting some lasting benefit to consistent use.
Common Side Effects
Because PDE5 inhibitors relax blood vessels throughout the body (not just in the penis), the most frequent side effects are related to blood flow. Headache, facial flushing, nasal congestion, and indigestion are the most commonly reported. Some men experience temporary changes in color vision, particularly a blue-green tint, especially with sildenafil. These effects are usually mild and fade within a few hours.
A more serious risk is a significant drop in blood pressure. This is especially dangerous for men taking nitrate medications for chest pain, such as nitroglycerin patches or tablets. Combining PDE5 inhibitors with nitrates can cause sudden, severe drops in blood pressure and coronary blood flow, potentially leading to a fatal cardiac event. This is an absolute contraindication, not a precaution. Men who use nitrates in any form cannot take these medications.
Conditions like heart disease, high blood pressure, and diabetes are associated with higher rates of ED, and the medications used to treat those conditions can sometimes worsen it. Smoking compounds the problem further. If you have any of these conditions, your prescriber will evaluate your cardiovascular health before starting treatment.
Generic Options and Cost
Generic versions of both sildenafil and tadalafil are widely available, and the price difference compared to brand-name versions is substantial. Through online pharmacies, generic tadalafil can start as low as $8 to $11 per prescription, depending on the dose and quantity. Brand-name Cialis, by comparison, can run $17 to $70 per prescription through the same platforms, or as high as $958 per month at full retail through others. For context, 30 brand-name Cialis pills might cost $400, while 30 generic tadalafil pills run about $100.
Sildenafil follows a similar pattern. Generic versions are available at a fraction of the original Viagra price. Most insurance plans cover generic PDE5 inhibitors, though they often limit the number of pills per month. Online telehealth platforms have made access easier, with many offering consultations and prescriptions without an in-person visit.
Non-Oral Treatments
For men who don’t respond to pills or can’t take them due to medication conflicts, several alternatives exist.
Alprostadil is the most established non-oral option. It works differently from PDE5 inhibitors, directly relaxing penile blood vessel muscle to produce an erection without requiring sexual arousal. It comes in two forms: an injectable version that you administer with a small needle into the side of the penis, and a tiny pellet that you insert into the urethra. The injectable form is highly effective, producing an erection firm enough for intercourse in about 80 percent of men. The urethral pellet version is less effective but avoids the need for a needle.
Vacuum erection devices are another option. These use a pump to draw blood into the penis, then a constriction ring at the base holds the blood in place. They’re drug-free and work for most men, though many find them cumbersome.
Eroxon: The First Over-the-Counter Option
A newer addition to the landscape is Eroxon, a non-medicated topical gel that received FDA clearance as an over-the-counter product. It works through a completely different mechanism than oral medications. You apply the gel to the head of the penis before sex. The alcohol and water in the formulation evaporate, creating a rapid cooling effect followed by a slower warming sensation. This temperature change stimulates nerve endings and triggers blood flow.
In clinical trials, 62 percent of men using Eroxon were classified as responders. About 63 percent noticed an erection within 10 minutes, and 56 percent were able to have penetrative sex within 15 minutes of application. Men with severe ED actually saw the largest improvement at 86 percent, compared to 55 percent for mild and 45 percent for moderate cases. Because it contains no medication, Eroxon doesn’t carry the blood pressure risks associated with PDE5 inhibitors, making it an option for men who take nitrates or other conflicting medications.