Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 2/1/2022
Erectile dysfunction (ED) is a common type of sexual dysfunction that can affect men of all ages and backgrounds. In the United States, approximately 30 million men are affected by some form of ED.
Dealing with erectile dysfunction can be a frustrating process. Luckily, several safe and effective medications are available to help you deal with ED and enjoy a fulfilling, satisfying sex life.
These include well-known ED pills such as Viagra®, as well as a large range of newer treatment options that offer long-lasting relief from erectile dysfunction.
There’s no “perfect” ED pill for everyone. Instead, each ED medication provides its own range of benefits, as well as certain downsides that you should be aware of before taking any medication to treat your erectile dysfunction.
Below, we’ve explained what ED is, why it occurs and the factors that may increase your risk of developing it. We’ve also shared the best erectile dysfunction pills and discussed how they can help you to more easily get and maintain firm erections.
Finally, we’ve shared the unique advantages and disadvantages of each ED medication to help you decide which treatment option is best for you.
For most guys, getting an erection is something that happens naturally, all without much in the way of thought or concentration. However, behind the scenes, a complex, multi-step process is involved in supplying your penis with the blood it needs to get and maintain an erection.
When you feel sexually aroused, your nervous system responds by triggering relaxation in the muscles of your corpora cavernosa -- a pair of sponge-like areas of erectile tissue that exist in your penis. This stimulates blood flow, causing your penis to become firm and larger in size.
A fibrous type of tissue called the tunica albuginea, which wraps around the corpora cavernosa, tightens to trap this blood inside your penis, helping you to sustain the erection.
When you reach orgasm and ejaculate, the same process occurs in reverse, with blood flowing out from your penis back into your circulatory system and your penis becoming smaller and less firm.
The process of getting an erection depends on several things, including proper blood flow, nerve function and sexual arousal.
Erectile dysfunction can occur when one or several physical or psychological issues prevent this process from occurring. These may include:
Diseases and conditions that reduce blood flow, such as high blood pressure, heart and blood vessel disease or atherosclerosis (clogged arteries).
Conditions that affect nerve function, such as type 2 diabetes, chronic kidney disease or injuries caused by surgery, accidents or treatment for prostate cancer.
Medicines that affect blood flow, sexual arousal or nerve function, such as tranquilizers, blood pressure medications, antiandrogens and antidepressants.
Psychological issues that affect relaxation and arousal, such as depression, anxiety and feelings of guilt about having sex.
Lifestyle factors that affect your physical or psychological well being, such as a physically inactive lifestyle, smoking, obesity, excessive alcohol consumption or illicit drug use.
Frequent use of pornography, which may affect the way you become aroused by real-life sexual activity and cause porn-induced ED.
Our guide to the causes of ED provides more information about how these factors can affect the sexual stimulation and erection process.
If you’ve spent any time looking up treatments for erectile dysfunction, you’ve almost certainly seen information about ED pills.
Currently, four different erectile dysfunction pills have been approved by the FDA. All four pills are prescription medications, meaning you’ll need to talk with your healthcare provider in order to use them, and all belong to a class of drugs referred to as PDE5 inhibitors.
Although there are a few differences between these medications, all work in the same general way: by making it easier for blood to flow into your penis when you feel aroused and ready for sexual activity.
These pills do this by reducing the effects of an enzyme called phosphodiesterase-5, or PDE5, which is responsible for regulating the dilatation of the blood vessels that supply your penis.
This makes it easier for you to get hard and also leads to a more prolonged erection, letting you focus on enjoying sex instead of worrying about your sexual function.
While these medications all work in the same general way, there are several subtle differences between each pill that could make one a better option for you than the others.
For example, certain ED pills have a longer half-life than others, meaning they’ll keep working for longer. Others are shorter-acting, making them a better choice for a single night than for an entire weekend.
We’ve profiled all four ED treatments below, along with information on which pill is typically the best for each purpose.
Best for: Men who need an affordable, convenient erectile dysfunction pill that works for up to four hours at a time.
Disadvantages: Only lasts for four hours and can only be used one time per day.
Sildenafil is the active ingredient in Viagra -- the oldest, most popular and well-known pill for treating erectile dysfunction. It’s been marketed on TV, in magazines and in just about every form of popular media for more than 20 years.
Viagra first came onto the market in the late 1990s and has been used ever since by men of all ages. These days, it’s widely available as a generic medication, meaning you no longer need to pay for brand name Viagra to access its benefits.
Like all of the medications listed on this page, sildenafil is a PDE5 inhibitor. It works by inhibiting the enzyme that controls blood flow to the soft tissue of the penis. This makes it easier for blood to flow into your penis, helping you get an erection.
Contrary to popular belief, sildenafil doesn’t affect your sex drive, cause random erections or do anything to your testosterone levels. Instead, it simply makes it easier to get and stay hard when you feel sexually aroused. You can read our article on how to stop male arousal if random erections are bothering you.
Sildenafil has several advantages. The first is that it’s affordable, readily available and effective as a treatment for ED. It can be found in just about every pharmacy in just about every location, making it a reliable choice if you’re looking for a convenient, easy-to-find ED pill.
A typical dose of sildenafil lasts for approximately four hours, making it a good option if you want an ED pill that’s designed to last for one night of sexual activity.
This relatively short duration of action is also great if you’re prone to side effects from ED drugs, as it means they may be less likely to affect you throughout the night and following day.
After you take sildenafil, it takes about 30 to 60 minutes for the medication to start working. You can safely take sildenafil with or without food, although taking it after a large, high-fat meal may slow down your body’s absorption of the medication.
Most men who use sildenafil are happy with its effects. In fact, in a 2002 study published in the journal Urology, more than 95 percent of men with erectile dysfunction who used sildenafil were satisfied with its effects on their erections and sexual function.
Another advantage of sildenafil is its lengthy track record. It’s been around for longer than any of the other ED pills, with a huge amount of published research on its effects and safety.
If you’re looking for a single-night ED treatment, sildenafil’s approximately four-hour duration of action makes it a convenient choice.
However, the fact that sildenafil can only be used once per day means that it’s not optimal if you want to have sex more than once per 24 hours. For example, if you take sildenafil around noon, you won’t be able to use it again at night.
Another minor downside of sildenafil is that its absorption is affected by food. If you take it with a meal that’s high in fat, it may take slightly longer to start working.
Sildenafil can cause certain side effects. Most of these are minor and temporary, although there are some that may be bothersome. Common side effects of sildenafil include headaches, facial flushing, nasal congestion, back and muscle pain, nausea, dizziness, vision issues and rash.
Like all ED drugs, sildenafil can potentially interact with other medications. It’s important to talk to your healthcare provider about all other medications you currently use or have recently used before taking sildenafil.
Overall, sildenafil is one of the best ED treatments if you need to treat erectile dysfunction for a few hours at a time. Its short duration of action means that you can take it after dinner for relief from ED when you need it, without any lingering effects the next morning.
Best for: Men who need a long-lasting pill to treat ED. A typical dose of tadalafil provides relief from ED for up to 36 hours, making it far longer-lasting than any other ED medication.
Disadvantages: May last longer than needed for many men. This medication’s long duration of action means that side effects can persist for longer than with other ED pills.
Tadalafil is the active ingredient in Cialis. It was approved by the FDA as a treatment for erectile dysfunction in 2003. Tadalafil is known for its long-lasting effects, with a normal dose providing relief from ED for up to 36 hours.
Like sildenafil and other ED medications, tadalafil is only available with a valid prescription from a healthcare provider.
Tadalafil has a half-life of 17.5 hours, meaning it remains active in your body for far longer than other ED medications. Thanks to its long half-life and duration of action, it’s often referred to as the “weekend pill” for treating erectile dysfunction.
Like sildenafil, tadalafil is a PDE5 inhibitor. It works in exactly the same way, by improving blood flow to the penis to help you get and maintain an erection. Because of this, it has similar effects and side effects.
The biggest advantage of tadalafil is its long half-life and duration of action. A normal dose of tadalafil can provide relief from ED for up to 36 hours, meaning a tablet taken on Friday night may still provide some effects on Sunday morning.
This long duration of action makes tadalafil a helpful choice if you want to have sex more than one time per day. If you only want to use a single ED pill for a weekend, a tadalafil prescription is likely going to be a more convenient choice for you than other ED treatments.
Tadalafil takes approximately one hour to start working. Like sildenafil and other ED pills, it can be taken with or without food.
Another advantage of tadalafil is that it’s also available as a daily-use medication. This version of tadalafil is ideal if you want to have sex spontaneously thoughout the day, or simply prefer to take your ED tablet on a daily basis instead of as needed.
Like sildenafil, tadalafil has a long track record. It’s been researched extensively, meaning both its effects and its side effects are well known.
Tadalafil’s biggest strength is also its biggest weakness. Because it’s such a long-lasting erectile dysfunction drug, the effects and potential side effects of tadalafil may continue for several days after a typical dose.
While this may be a good thing if you’re looking for long-lasting relief from ED, if you’re prone to side effects from oral medication for ED, you may prefer to use a shorter-acting ED medication, such as sildenafil, vardenafil or avanafil.
A second disadvantage of tadalafil is its price. Tadalafil is slightly more expensive than sildenafil on a per-tablet basis, although this may be less of a concern if you have sex more than one time per dose.
Overall, tadalafil is the best ED medication on the market if you’re looking for long-lasting relief from erectile dysfunction. It’s also a great option if you prefer a once-daily pill to the as-needed dosage form of other ED medications.
Best for: Men who want a slightly longer-lasting ED pill than sildenafil, but don’t want the all-day effects provided by tadalafil.
Disadvantages: Generally more expensive than sildenafil. Like sildenafil, vardenafil can only be taken one time per day.
Vardenafil is the active ingredient in Levitra. It was approved by the FDA in 2003. Vardenafil is a similar medication to sildenafil, although it lasts for slightly longer, with research suggesting that it offers continued benefits for up to eight hours.
As with other ED medications, vardenafil is only available with a valid prescription, meaning you will need to schedule a consultation with a healthcare provider before you can purchase it.
The main advantage of vardenafil is that it lasts for slightly longer than sildenafil. The half-life of vardenafil is approximately four to five hours, and the medication may provide relief from ED for up to eight hours per dose.
This means that if you take vardenafil shortly after dinner, it may remain active and continue to provide relief from ED until after midnight.
Because of its slightly longer duration of action, vardenafil can be a better choice than sildenafil if you plan to have sex more than one time per night.
Like sildenafil and tadalafil, vardenafil should be taken about 60 minutes before sex, either with or without food.
Like sildenafil, vardenafil can only be used one time per day. This means it may not be the best ED medication if you plan to have sex several times in a day -- for example, once in the daytime and once at night.
Vardenafil also has similar side effects to other ED drugs. Common adverse effects of vardenafil include headache, nasal congestion, facial flushing, dyspepsia (indigestion), inflammation of the sinuses, dizziness, flu syndrome, back pain, nausea and elevated creatine kinase levels.
Like tadalafil, vardenafil is usually more expensive than sildenafil on a per-dose basis. This may make it a less appealing treatment if you’re budget conscious and only need relief from erectile dysfunction for a few hours at a time.
Best for: Men who want a fast-acting ED pill that can be taken almost immediately before sex and is less likely to cause side effects such as headaches, flushing and nasal congestion.
Disadvantages: Not yet available as a generic medication, meaning it’s more expensive than other ED drugs. Although side effects are less common, they can still occur.
Avanafil is the active ingredient in Stendra, a new ED medication that received FDA approval in 2012. Avanafil is a newer-generation PDE5 inhibitor that’s more selective for PDE5 than other phosphodiesterase enzymes.
This increased selectivity for PDE5 means that avanafil is less likely to cause some side effects than older PDE5 inhibitors such as sildenafil, tadalafil and vardenafil.
As a second-generation PDE5 inhibitor, avanafil offers several advantages over older drugs for treating erectile dysfunction.
The first is that avanafil is faster acting than older medications. It’s designed for use 30 minutes before sex, although research suggests that it’s still effective at treating ED when it’s taken only 15 minutes before sexual activity.
This means that it can be taken very shortly before sex, either with or without food, without any need to wait for one hour for adequate relief from ED.
Because avanafil is more selective for PDE5 than older ED medications, it’s less likely to cause some side effects, such as headaches, facial flushing, nasal congestion or back pain.
If you’re prone to side effects from sildenafil, tadalafil or vardenafil, switching to avanafil may be a helpful way to access the benefits of prescription ED medication with a milder, more tolerable side effect profile.
The biggest disadvantage of avanafil is its cost. Because avanafil is a newer ED medication, it’s still under patent protection and is only sold as Stendra. Currently, there is no generic version of avanafil available in the United States.
Although certain side effects are less common with avanafil than with older medications for ED, they can and often do still occur. Side effects of avanafil include headache, flushing, back pain, nasal congestion and nasopharyngitis (cold-like symptoms in the nasal passages).
Sildenafil, tadalafil, vardenafil and avanafil are safe and effective medications that are used by millions of men on a regular basis.
However, all medications for ED have the potential to interact with other medications, including some medications used to treat hypertension (high blood pressure) and heart disease.
When used with nitrates, ED medications can cause a sudden drop in blood pressure that may be life threatening. The medications listed above may also interact with antihypertensives and alpha blockers, as well as certain medications that inhibit the enzyme CYP3A4.
Some recreational drugs, such as amyl nitrite “poppers,” may also cause potentially dangerous interactions when used with ED medication.
Although very uncommon, ED medications may cause priapism -- prolonged, painful erections that can damage the tissue of your penis.
Because of these interactions and safety risks, it’s important to inform your healthcare provider about any medications you currently use or have recently used before taking any medication to treat erectile dysfunction.
It’s also important to talk to your healthcare provider about your medical history and the severity of your ED.
What is the best pill to stay hard? Since ED symptoms can differ from person to person and everyone’s needs are different, there isn’t a single “best” erectile dysfunction pill for every man. Each ED pill offers a slightly different experience, from a longer duration of action to a reduced likelihood of certain side effects.
If you’re looking for an affordable, readily available ED medication that provides relief from erectile dysfunction for four hours, sildenafil is an excellent choice.
If you’re looking for a long-lasting ED medication that you can take once a day or use over the weekend, tadalafil is a better option.
If you’re looking for an ED medication that lasts for a single night and provides slightly longer-lasting effects than sildenafil, vardenafil is worth considering.
If you’re prone to side effects from ED medication, or if you want something that works very quickly, Stendra is likely a good option for you.
If you start using an ED medication but think a different pill might be more suited to your needs, you can always talk to your healthcare provider about switching. It’s common and normal to try several medications before finding the one that works best for you.
Erectile dysfunction is a common issue that can affect your sexual performance, relationships and self-confidence. The good news is that ED is almost always treatable with the right mix of good habits, self-care and medication.
We offer several FDA-approved erectile dysfunction medications online, including Viagra and generic sildenafil, Cialis and generic tadalafil and Stendra, which are available after an online consultation with a licensed healthcare provider.
Used 15 to 60 minutes before sex, these medications can help you to get hard and sustain an erection firm enough for satisfying sex.
Want to learn more about ED before getting started? Our detailed guide to erectile dysfunction explains how and why ED occurs, the symptoms you might notice if you’re affected by ED and the steps that you can take to gain more control over your sexual function.