ED medication most commonly refers to a class of prescription drugs called PDE5 inhibitors, which include familiar names like sildenafil (Viagra) and tadalafil (Cialis). These pills are the first-line treatment recommended by both American and European urology guidelines, and they work by enhancing blood flow to the penis during arousal. But the full landscape of ED treatment extends well beyond a single pill, spanning topical creams, self-administered injections, mechanical devices, hormone therapy, and even emerging regenerative approaches.
How PDE5 Inhibitors Work
When you become sexually aroused, nerve signals trigger the release of nitric oxide in the penile tissue. Nitric oxide sets off a chain reaction that produces a molecule called cGMP, which relaxes smooth muscle in the blood vessels of the penis, allowing blood to flow in and create an erection. The body also produces an enzyme, PDE5, that breaks cGMP down, which is why erections naturally subside. PDE5 inhibitors slow that breakdown, letting cGMP accumulate and sustain the erection longer. They don’t create arousal out of thin air; they amplify the body’s existing response to sexual stimulation.1Nature. Synergy between oral PDE5 inhibitors and topically applied nitric oxide microparticles on the erectile response in a rat model of cavernous nerve injury
This mechanism explains why PDE5 inhibitors don’t work for everyone. If the underlying nerve signaling is severely impaired, so little nitric oxide gets released that there isn’t enough cGMP for the drug to preserve. The pills need at least some baseline signal to have something to work with.
The Four PDE5 Inhibitors and How They Differ
Four PDE5 inhibitors are currently approved for ED, and while they share the same basic mechanism, they differ in how quickly they kick in, how long they last, and what side effects they tend to cause. The differences come down to pharmacology, not potency: all four can produce equivalent results in the right patient, so choosing between them is more about lifestyle fit than raw effectiveness.
- Sildenafil (Viagra): The original, approved in 1998. It was actually developed as an angina drug before its effect on erections became apparent during clinical trials.2PubMed Central. Sildenafil: from angina to erectile dysfunction to pulmonary hypertension and beyond It typically takes effect within 30 to 60 minutes and lasts roughly four to six hours. Food, especially fatty meals, can delay absorption.
- Tadalafil (Cialis): Known for its long duration of action, often lasting up to 36 hours, which earned it the nickname “the weekend pill.” It’s also the only PDE5 inhibitor approved for daily low-dose use.
- Vardenafil (Levitra): Similar in onset and duration to sildenafil, with a slightly different side-effect profile. It’s less commonly prescribed now but remains a useful option for men who don’t respond well to the others.
- Avanafil (Stendra): The newest of the group, sometimes called a second-generation PDE5 inhibitor. It can work in as little as 15 minutes, with a shorter half-life of about three to five hours. The rapid onset makes it appealing for spontaneity, and its selectivity for PDE5 over other phosphodiesterase enzymes may translate to fewer side effects for some users.3PubMed Central. Efficacy and safety of avanafil as compared with sildenafil in the treatment of erectile dysfunction: A randomized, double blind, multicenter clinical trial
One quirk of sildenafil worth knowing about: it has minor activity against PDE6, an enzyme found exclusively in the photoreceptors of the retina. This is why some men notice a blue-tinged vision or increased light sensitivity at higher doses. The visual effects are mild and temporary, but they’re a direct result of the drug’s imperfect selectivity.4PubMed Central. Visual Side Effects Linked to Sildenafil Consumption: An Update
Daily Dosing Versus On-Demand Use
Most men take PDE5 inhibitors on an as-needed basis before sexual activity. But tadalafil is also prescribed as a daily low dose (typically 2.5 or 5 mg), and this regimen has some distinct advantages. A 12-week randomized trial found that daily tadalafil was superior to on-demand sildenafil in improving erectile function scores and was at least as effective as on-demand tadalafil, with particularly strong results for the ability to achieve penetration.5PubMed Central. Comparative efficacy of on-demand Sildenafil, Tadalafil and daily Tadalafil for treatment of erectile dysfunction: A 12-week randomized controlled study
Daily dosing removes the need to plan around a pill. You don’t have to time intercourse within a window, which some couples find reduces performance anxiety. It also maintains a steady drug level, which can help men whose ED has a significant vascular component. The trade-off is cost: you’re taking a pill every day rather than a few times a month, and that adds up.
What ED Medication Costs
Pricing for ED medication varies enormously depending on whether you’re buying a brand-name or generic product, filling a traditional pharmacy prescription, or using a direct-to-consumer telehealth platform. Generic sildenafil and tadalafil have driven prices down substantially since their patents expired. A recent review of direct-to-consumer pricing found that sildenafil ranged from about $0.50 to $35 per pill and tadalafil from roughly $0.50 to $9.80 per pill.6PubMed Central. Direct-to-Consumer Erectile Dysfunction Medications: is the Convenience Worth the Cost? That enormous spread reflects the difference between a bare-bones generic and a branded product bundled with a telehealth consultation and subscription fee.
Direct-to-consumer platforms like Hims, Ro, and others have made getting a prescription more convenient. You fill out a health questionnaire, a clinician reviews it (often asynchronously), and medication ships to your door. The convenience is real, but it comes at a premium. You can often find the same generic pill for far less at a local pharmacy with a GoodRx coupon or similar discount tool. Insurance coverage for ED medication is inconsistent; many plans exclude it entirely, treating it as a lifestyle drug.
Safety, Side Effects, and One Critical Drug Interaction
PDE5 inhibitors are generally well tolerated. The most common side effects are headache, flushing, nasal congestion, and indigestion, all of which tend to be mild and fade as the drug clears your system. The visual disturbances with sildenafil mentioned earlier fall into this category as well.
The one safety issue that rises above “annoying side effect” is the interaction with nitrate medications. Nitrates, prescribed for chest pain from angina (drugs like nitroglycerin, isosorbide mononitrate, or isosorbide dinitrate), work by releasing nitric oxide. Because PDE5 inhibitors amplify the downstream effects of nitric oxide, combining the two can cause a dangerous and potentially life-threatening drop in blood pressure.7PubMed Central. A New Perspective on the Nitrate-Phosphodiesterase Type 5 Inhibitor Interaction This is an absolute contraindication, not a caution. If you take nitrates for heart disease, PDE5 inhibitors are off the table, and you should tell any prescribing clinician about all your medications before starting treatment.
When Pills Don’t Work
Roughly a third of men don’t get satisfactory results from PDE5 inhibitors alone. For them, several second-line options exist.
Penile Injections
Intracavernosal injection therapy, or ICI, involves injecting a vasodilating medication directly into the side of the penis before intercourse. The concept dates back to 1982, and both the American Urological Association and the European Association of Urology recommend it as a second-line treatment when oral medications fail.8Expert Opinion on Pharmacotherapy. Current status of intracavernosal injection therapy in erectile dysfunction The injections use medications like alprostadil, papaverine, or a combination. The needle is small, the injection is into soft tissue (not a vein), and most men report the discomfort is far less than they expected. Erections typically develop within five to fifteen minutes and last about 30 to 60 minutes.
Topical Alprostadil
For men who can’t tolerate injections, alprostadil is also available as a cream applied to the tip of the penis. Alprostadil is a synthetic version of prostaglandin E1, which directly relaxes smooth muscle to increase blood flow. The cream has a favorable safety profile because very little of it enters the bloodstream: imaging studies have shown that about 99% of the topically applied cream stays localized at the application site.9Research and Reports in Urology. Clinical use of alprostadil topical cream in patients with erectile dysfunction: a review This minimal systemic absorption means fewer side effects compared to oral or injected medications.10PubMed Central. Alprostadil cream in the treatment of erectile dysfunction: clinical evidence and experience The downside is that the cream tends to produce somewhat less rigid erections than injections.
Mechanical Devices and Surgical Implants
Vacuum erection devices (VEDs) are non-invasive tools that use negative pressure to draw blood into the penis, followed by a constriction ring at the base to maintain the erection. They work reliably, have no drug interactions, and are particularly useful for men who can’t use medications due to heart conditions or other contraindications. The erection feels somewhat different from a natural one since the blood is trapped rather than flowing freely, but many couples adapt comfortably.
For men who have exhausted other options, an inflatable penile prosthesis is the most definitive surgical solution. It involves surgically implanting a fluid-filled system inside the penis, with a pump placed in the scrotum. Squeezing the pump transfers fluid into cylinders that produce a rigid erection on demand. The procedure is irreversible in the sense that it alters the internal anatomy, but satisfaction rates among men and their partners are consistently high.11PubMed. Implants, mechanical devices, and vascular surgery for erectile dysfunction
Testosterone Therapy for Men With Low Levels
Testosterone replacement is not an ED treatment in the way PDE5 inhibitors are. It doesn’t work for men with normal testosterone levels. But for men whose ED is partly or fully caused by clinically low testosterone (hypogonadism), restoring testosterone to a normal range can meaningfully improve erections and libido. Multiple randomized controlled trials have demonstrated this benefit.12PubMed Central. Testosterone Therapy Improves Erectile Function and Libido in Hypogonadal Men A meta-analysis of testosterone therapy trials found significant improvements in erectile function scores among hypogonadal men, supporting the idea that sexual dysfunction should be considered a core symptom of testosterone deficiency.13PubMed. Meta-analysis of Results of Testosterone Therapy on Sexual Function Based on International Index of Erectile Function Scores
In practice, testosterone therapy is often combined with a PDE5 inhibitor, especially when a man has both low testosterone and vascular risk factors. Normalizing testosterone can make PDE5 inhibitors more effective in men who were previously poor responders.
Lifestyle Changes That Actually Help
This is the unsexy part of ED treatment that often gets skipped, but the evidence is solid. Erectile function depends heavily on vascular health, and anything that damages blood vessels, obesity, inactivity, smoking, uncontrolled diabetes, increases the risk of ED. A systematic review and meta-analysis found that men following a Mediterranean-style diet saw meaningful improvements in erectile function scores and measurable improvements in endothelial function, the ability of blood vessels to dilate properly.14JAMA Internal Medicine. The Effect of Lifestyle Modification and Cardiovascular Risk Factor Reduction on Erectile Dysfunction: A Systematic Review and Meta-analysis
Exercise and caloric reduction in overweight men produced additional benefits, likely through reduced inflammation, improved insulin sensitivity, and decreased visceral fat.15The Journal of Sexual Medicine. Beneficial Impact of Exercise and Obesity Interventions on Erectile Function and its Risk Factors None of this replaces medication when it’s needed, but for men with mild ED and metabolic risk factors, lifestyle changes alone can sometimes resolve the problem. At a minimum, they improve the odds that medication will work.
When ED Is Psychological
Performance anxiety, relationship conflict, depression, and stress can all cause or worsen ED, and pills alone don’t address those drivers. A pilot study that combined sildenafil with cognitive-behavioral sex therapy found that after four weeks, about 48% of men in the combined group met criteria for erectile function success, compared to 29% of men taking sildenafil alone. Satisfaction rates showed an even bigger gap: roughly 66% versus 38%.16The Journal of Sexual Medicine. Integrated Sildenafil and Cognitive-Behavior Sex Therapy for Psychogenic Erectile Dysfunction: A Pilot Study The medication helped break the cycle of failure and anxiety, while therapy addressed the underlying pattern. For psychogenic ED, this combined approach consistently outperforms either intervention alone.
Partner involvement matters too. Research on treatment adherence has found that a partner’s active support and satisfaction with treatment are important factors in whether men stick with their ED regimen long-term. Clinicians are encouraged to include partners in treatment discussions when possible.17European Urology Supplements. The Role of the Partner in the Successful Treatment of Erectile Dysfunction with Oral Phosphodiesterase Type 5 Inhibitors
Penile Rehabilitation After Prostate Surgery
Radical prostatectomy, the surgical removal of the prostate for cancer, commonly causes ED because the nerves responsible for erections run alongside the prostate. Even with nerve-sparing surgical techniques, recovery of natural erections can take 18 to 24 months. The concept of “penile rehabilitation” has become standard practice: men are instructed to achieve medication-assisted erections two to three times per week during the recovery period, with or without sexual activity, to maintain tissue health. Data suggest that roughly 52 to 67% of men who follow a penile rehabilitation program recover erections, compared to about 20% of those who don’t.18PubMed Central. Erectile Dysfunction after Radical Prostatectomy: Prevalence, Medical Treatments, and Psychosocial Interventions Rehabilitation programs typically use PDE5 inhibitors, sometimes combined with vacuum devices or low-dose injections.
Counterfeit Pills and Spiked Supplements
Buying ED medication from unverified online sources is genuinely risky. A study examining internet-purchased Viagra found that 77% of the tablets were counterfeit, with active ingredient content ranging between 30% and 50% of what the label claimed. The counterfeits also lacked safety information leaflets.19PubMed. Internet-ordered viagra (sildenafil citrate) is rarely genuine Broader analyses of counterfeit PDE5 inhibitors have found even worse problems: active ingredient doses ranging from zero to more than double the labeled amount, along with contaminants including commercial paint and printer ink.20PubMed Central. Counterfeit phosphodiesterase type 5 inhibitors pose significant safety risks
The “natural” supplement market presents a different version of the same problem. A study testing 91 purportedly herbal sexual enhancement supplements found that 81% contained undeclared synthetic PDE5 inhibitors, including sildenafil and tadalafil. Nearly a quarter of those contained more than 110% of the highest approved prescription dose. The supplements claimed to contain no synthetic substances, and the variability between tablets within the same product indicated almost no manufacturing quality control.21PubMed. Adulteration of purported herbal and natural sexual performance enhancement dietary supplements with synthetic phosphodiesterase type 5 inhibitors If you’re taking one of these products and it seems to work, the most likely explanation is that you’re unknowingly taking an unregulated dose of a prescription drug, potentially at dangerous levels, and potentially on top of medications it interacts with.
Low-Intensity Shockwave Therapy
One of the more interesting developments in ED treatment is low-intensity extracorporeal shockwave therapy (Li-ESWT), which aims to treat the root cause of vascular ED rather than just manage symptoms. The therapy uses acoustic pulses directed at penile tissue, with the goal of stimulating new blood vessel growth and improving blood flow. An umbrella review of five systematic reviews and meta-analyses found a statistically significant improvement in erectile function scores in the shockwave group compared to placebo, with better outcomes observed at specific energy and pulse parameters.22PubMed Central. Effectiveness of Low-Intensity Extracorporeal Shock Wave Therapy in Erectile Dysfunction: An Analysis of Sexual Function and Penile Hardness at Erection: An Umbrella Review The results are promising, but the field is still working out optimal treatment protocols, and long-term durability of improvements remains an open question. Most guidelines consider it experimental rather than standard-of-care, and it’s typically not covered by insurance. Clinics offering the treatment vary widely in equipment quality and protocol adherence, so anyone considering it should look for a urologist with specific experience rather than a med-spa.