Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 5/25/2021
Often referred to as the “little blue pill,” Viagra® (which contains the active ingredient sildenafil) was developed throughout the 1980s and 1990s as a treatment for cardiovascular issues such as angina (chest pain).
After researchers identified the drug’s benefits for treating the symptoms of erectile dysfunction in the early 1990s, they rebranded the drug as a treatment for erectile dysfunction (ED).
Viagra was first approved by the FDA as a treatment for ED in 1998 and quickly became one of the most widely used medications in the country for men.
Within six months of the date it was approved by the FDA, upwards of five million prescriptions were written for Viagra.
Over the next two decades, numerous other ED medications, such as tadalafil (sold as Cialis®), vardenafil (Levitra®) and avanafil (Stendra®) also came onto the market.
Viagra and other ED medications are effective for most men. However, not everyone who uses them experiences benefits.
If you suffer from erectile dysfunction and find that medications like Viagra don’t work as well as you’d like them to, it’s important to understand that other options are available that may be able to improve your erectile function and sexual health.
Below, we’ve explained how ED medications like Viagra work, as well as the type of effects you should notice after using these medications.
We’ve also discussed why ED medications sometimes don’t work, as well as the steps that you can take to treat your erectile dysfunction and improve your sexual performance if you don’t get the expected benefits from medications like Viagra.
Finally, we’ve shared some lifestyle tips that you can implement for better erections and sexual performance.
The risk factors for erectile dysfunction are vast and varied but, for the most part, the underlying issue comes down to one thing: circulation.
Like any other organ inside your body, the penis requires a supply of oxygenated blood in order to perform basic functions.
When it comes to sexual function, healthy blood circulation is key to getting and maintaining an erection.
When you feel sexually aroused, your nervous system stimulates the tissue of your penis. This causes the muscles of the corpora cavernosa -- a pair of sponge-like areas of erectile tissue -- to relax, allowing blood to freely flow into your penis and expand the tissue.
As blood flows to this tissue, a fibrous membrane called the tunica albuginea contracts, trapping the blood inside your penis and helping to sustain your erection during sex.
After you reach orgasm and ejaculate, this process occurs in reverse, with the tunica albuginea relaxing and blood flowing out of your erectile tissue.
Erectile dysfunction can occur for several reasons, but one of the most common is weak blood flow to your penis.
When blood can’t freely flow into your corpora cavernosa, it can become difficult or impossible for you to get and maintain an erection.
The primary function of ED drugs is to resolve the vascular issues that affect blood flow to your penis, making it easier for blood to flow to your penis and facilitate an erection.
ED medications like Viagra belong to a class of drugs called phosphodiesterase-5 inhibitors, or PDE5 inhibitors for short.
They work by inhibiting the effects of an enzyme called PDE5, which regulates blood flow within certain areas of your body.
By inhibiting the effects of PDE5, medications like Viagra help to relax the smooth muscle inside your blood vessels and increase blood flow to your penis.
This can make it easier for you to get and maintain an erection when you feel sexually aroused.
Most men with erectile dysfunction experience notice in their erections and sexual performance after they use Viagra or similar ED medications.
However, it’s far from uncommon to experience erectile dysfunction even after you take ED medication.
Why is Viagra not working for you? There are a few reasons why ED can persist even after you start to use medication.
The first is that you could be using the medication improperly. Many guys make mistakes when using medications like Viagra or Cialis that can reduce their effectiveness.
The second is that your ED could be caused by an issue that’s unrelated to blood flow, such as sexual performance anxiety, damage to your nerves or being sick.
The third is that you may simply not be a good fit for the specific medication you’re using. If this is the case, switching medications may help you.
We’ve gone into greater detail about what you can do in each of these situations below, starting with common mistakes many guys make when using ED medications like Viagra.
While erectile dysfunction medications might seem easy to use -- just take the medication with a glass of water before you have sex -- the reality is that there’s something of a technique to using them correctly.
Below, we’ve covered six common mistakes men make when using ED medications, as well as the steps that you can take to correct each one for better results.
ED medications like Viagra have a real, measurable effect on blood flow to your penis, but their effects aren’t immediate.
After you take ED medication, it can take anywhere from 15 minutes to approximately one hour to start working.
If you have sex before your medication is effective, you might find it difficult to get and maintain an erection. Because of this, it’s best to take your medication at least one hour before you plan to have sex.
Try to avoid having a large, high-fat meal with your medication, as this can affect the absorption rate of drugs like Viagra.
If you don’t want to have to precisely time your ED medication usage before sex, consider using a long-lasting medication like Cialis, which provides relief from ED for up to 36 hours per dose.
Erectile dysfunction can vary significantly in severity. While one man may have mild ED that can be treated with a relatively light dose of Viagra or similar medication, another might have a more severe case of ED that requires a stronger dose.
If you still experience ED after using Viagra or similar medication, it may be worth talking to your healthcare provider about adjusting your dosage.
Viagra is available in three strengths: 25mg, 50mg and 100mg. Research shows that men with ED are more likely to report improvements in their erections when they’re prescribed a 50mg or 100mg dose of Viagra.
Everyone’s needs are different, meaning a dose that’s perfect for someone else may not be the best option for you.
If you’re worried that you may not be taking a strong enough dose of Viagra or similar ED medication, don’t be afraid to reach out to your healthcare provider for help.
Viagra and other medications for ED work by increasing blood flow to your penis, but they don’t have any effect on sexual arousal.
This means that if you aren’t in the mood for sex, taking Viagra won’t suddenly cause your sex drive to become stronger.
A variety of factors can contribute to a low sex drive in men, from psychological disorders such as depression and chronic stress to relationship problems, sleep apnea and even low levels of testosterone.
If your ED is caused by a psychological arousal issue rather than a cardiovascular one, Viagra and similar medications may not be fully effective.
Although ED medications like Viagra, Cialis, Levitra and Stendra work well for most men, some guys don’t experience any improvements the first few times they take medication.
This is fairly common. It might be linked to nervousness about using ED medication for the very first time, or it could simply be sexual performance anxiety.
If you take Viagra or similar ED medication and don’t notice any improvements when you try to have sex, don’t give up on it immediately.
Instead, try using your medication several times before you start to judge your results. You may find that it becomes more effective as you grow more accustomed and comfortable with using it before sex.
If you don’t notice any improvements after using Viagra or similar ED medication several times, it’s best to reach out to your healthcare provider.
Erectile dysfunction is often caused by underlying medical issues, such as high blood pressure, atherosclerosis (blocked arteries), type 2 diabetes and chronic kidney disease.
Certain medications, such as antiandrogens, antidepressants, tranquilizers and blood pressure medications, may also cause erectile dysfunction as a side effect.
If you have an underlying medical condition, or if you use one of the types of medication listed above, ED medications like Viagra may not be fully effective for you.
In this case, it’s best to talk to your healthcare provider to work out what you can do to treat ED and improve your sexual performance.
Everyone responds slightly differently to medications, including medications prescribed to treat erectile dysfunction.
If the first erectile dysfunction drug your healthcare provider prescribes isn’t working or doesn’t give you the results you expected, consider talking to your healthcare provider about switching to another medication.
Although all oral medications for ED work by inhibiting the effects of PDE5, some men find that one drug is a better choice for them than others.
For example, you might like the long-lasting effects of Cialis over the more short-lived effects of Viagra or Levitra.
Alternatively, you may like the fast-acting effects and low side effect risk of a newer medication such as Stendra.
It’s far from uncommon to try several medications before settling on one that provides the right combination of results and user-friendliness for you.
In one study of 170 men experiencing ED due to spinal cord injuries, experts found that nearly 90 percent of subjects saw an improvement in their erection quality.
A meta analysis involving 27 studies and more than 6,600 men also concluded that, based on the data currently available, sildenafil (the active ingredient in Viagra, generic Viagra) was more likely to allow men to successfully have sex than a placebo (57 percent vs. 21 percent, respectively).
This research also found that 83 percent of ED-affected men who used sildenafil were able to successfully have sex at least once during the study period.
Despite these findings, an article published by Harvard Health Publishing suggests that drugs like Viagra fail to work for around 30 percent of men who take them.
ED medications like Viagra are safe for most men, but they can potentially cause side effects and interact with other drugs.
Common side effects of Viagra include:
Flushing of the skin
Myalgia (muscle aches)
Other ED medications, such as Cialis and Levitra, can also cause side effects. We’ve discussed these in more detail in our guide to what to expect from erectile dysfunction medication.
It’s also important to be aware that ED medications can interact with certain other drugs used to treat high blood pressure, heart disease, seizures and other medical conditions.
As such, it’s important to inform your healthcare provider if you use any other medication before you start taking Viagra or similar PDE5 inhibitors.
Our guide to sildenafil interactions lists major interactions that you should be aware of before using medication to treat ED.
If medications like Viagra don’t seem to work for you, there’s no need to panic. Other treatments are available that may be able to improve your erectile function and allow you to enjoy a fulfilling and satisfying sex life.
Some of the most common alternative treatments for ED include the following:
Injectable ED medications
Vacuum constriction devices (penis pumps)
Your healthcare provider may suggest one of these options if your ED is linked to an underlying health issue that makes oral ED medication ineffective or unsuitable for you.
When oral medications aren’t effective at treating your erectile dysfunction, another option is to use medication that’s injected directly into your penis.
While the idea of injecting medicine into your penis may not sound appealing, the reality is that injectable ED medication is effective for many men who don’t respond to oral medications such as Viagra.
Currently, the only medication of this type that’s approved by the FDA for erectile dysfunction is alprostadil, which is sold under the brand names Cavarject® and Edex®.
Alprostadil is a vasodilator that works by relaxing the muscles and blood vessels in your penis, allowing blood to flow into your penis when you’re sexually aroused.
On average, it takes five to 20 minutes to get an erection after using alprostadil. The effects of this medication last for 30 minutes to one hour, with the medication designed for use up to three times per week.
If you (quite understandably) don’t like the idea of using a needle to apply medication directly to your penis, you may want to consider using a urethral suppository, or pellet.
ED suppositories also contain alprostadil. Instead of being injected into the tissue of your penis, this type of medication comes as a small medicated pellet that’s inserted into your urethra using a simple handheld device.
This type of medication is often referred to as the “Medicated Urethral System for Erections,” or MUSE.
When it’s used in suppository form, alprostadil is absorbed through the walls of the urethra and acts quickly to improve blood flow.
On average, it takes approximately five to 10 minutes to get an erection after using this form of ED medication.
If your ED is caused by a physical injury that affects your penis, such as injury from surgery for prostate or bladder cancer, medications for ED may not be completely effective.
In this case, your healthcare provider may suggest using a vacuum constriction device (VCD), or penis pump.
Devices of this type work by drawing blood into your penis through a vacuum, which creates an erection.
You’ll normally use a VCD with a band that attaches around the base of your penis in order to trap blood inside and sustain your erection during sex.
Another option for treating severe ED is the installation of a penis implant. This type of device is placed inside your penis and creates an erection using either an internal fluid mechanism or with a semi-rigid rod.
Placing a penile implant is a significant surgical procedure. As such, this type of treatment tends to be used for men who’ve tried other treatment options without success.
Although many cases of ED are related to physical health issues, mental health issues such as depression, anxiety and stress can often cause psychological ED.
If your erectile dysfunction is linked to a mental health issue, you may experience improvements in your erections and sexual function with therapy.
One form of therapy that can be helpful for treating sexual health issues is cognitive behavioral therapy, or CBT.
This type of therapy involves identifying and changing negative or destructive thought processes and behaviors that affect your sexual function and wellbeing.
Research suggests that it can help men with ED improve their erectile function and sexual health.
Although ED medications can help to reduce the symptoms of ED and make it easier to develop and maintain an erection, they don’t address the underlying issues that often cause ED.
Some of the most common risk factors for erectile dysfunction include obesity, smoking, alcohol consumption, diabetes, high cholesterol, stress, poor diet and a sedentary lifestyle.
It’s often possible to improve your erections naturally by making certain changes to your habits and lifestyle.
Good ways to improve your sexual health naturally include eating a healthy, balanced diet that’s high in fresh fruits, vegetables and lean sources of protein, exercising regularly and maintaining a body weight in the healthy range.
If you smoke, quitting may also help to improve your erections and sexual performance. This is because smoking can harm your vascular system and reduce blood flow throughout your body, including to your penis.
You can learn more about natural methods that you can use to treat ED in our guide to naturally protecting your erection.
Erectile dysfunction is a very common condition that affects approximately 30 million men in the United States alone.
If you’re prescribed medication for ED and don’t think it’s working correctly, it’s best to reach out to your healthcare provider for assistance.
You may be able to improve your results by adjusting your dose, changing the way you use your medication or switching to a different treatment for ED.
Making simple but effective changes to your habits and lifestyle might also help to improve your erectile function and sexual health.
Our guide to erectile dysfunction goes into greater detail about the most common causes of ED, as well as the most effective options for improving your erections and sexual performance.
If you think you may have ED and want to seek help, you can view our range of ED treatments online and, if necessary, connect with a licensed healthcare provider to access medication. Here is a guide on where to buy Viagra.