Viagra: How a Little Blue Pill Changed the World

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Oct 4, 2023.

What is the "little blue pill?"

Often dubbed "the little blue pill", Viagra (sildenafil) was the first phosphodiesterase 5 (PDE5) inhibitor approved to treat erectile dysfunction (ED). ED is a common sexual problem for men and its frequency increases with age.

It is estimated roughly 30 million men in the U.S. and over 100 million men worldwide suffer from ED. In addition, men with diabetes are three times more likely to have ED. 

Viagra (sildenafil) is one of the most widely-known prescription drug brand names on the U.S. market.

How was Viagra discovered?

The discovery that active ingredient in Viagra known as sildenafil could lead to an erection wasn't exactly a planned event.

• The sildenafil compound was originally developed by Pfizer for the treatment high blood pressure (hypertension) and angina pectoris (chest pain due to heart disease).
• During the heart clinical trials, researchers discovered that the drug was more effective at inducing erections than treating angina.
• Pfizer realized ED was an unmet medical need and a major opportunity for financial gain. In 1998, the FDA approved Viagra, the first oral treatment for erectile dysfunction, under a priority review.

Today, sildenafil is still used to treat a form of hypertension in the lungs, known as  pulmonary arterial hypertension (PAH). Revatio is an oral tablet or injectable form of sildenafil used in adults. Liqrev (sildenafil) suspension, approved in 2023, is also used to treat PAH in adults.

These products work by relaxing blood vessels in the lungs to lower blood pressure and help pump out more blood from the heart. This helps to improve the patients' ability to exercise and can delay clinical worsening from PAH.

Patients who take Revatio or Liqrev should not take Viagra or any other PDE-5 inhibitors.

How successful was Viagra?

At the time of its approval in 1998, Viagra had the fastest initial sales growth of any prescription product following its launch, reaching annual sales of over to $2 billion in 2012, at its peak. Even in 2019, after the approval of generic Viagra known as sildenafil, Viagra still generated around $500 million in U.S. revenue.

Advertising played a big part in sales. Pfizer promoted Viagra and ED awareness via direct-to-consumer (DTC) advertising, which prompted men to seek medical advice and a prescription from their doctors.

For many men, the stigma and embarrassment of talking to their doctor about ED has declined since the introduction of Viagra and other PDE5 inhibitors. Today, health care professionals regularly ask men of all ages about sexual dysfunction as part of their regular check-ups.

What is the impact of ED on men?

Erectile dysfunction (ED), or the inability to achieve and maintain an erect penis for sexual function, can lead to performance anxiety, a negative impact on self-esteem and personal relationships, and even clinical depression.

In a survey published in BMJ, 62% of men reported a decline in self esteem, 29% reported a negative effect on a relationship, and 21% reported that their relationship had ceased due to ED.

For many men, the inability to perform adequately during sex directly affects their feelings of masculinity. The availability of ED treatments like Viagra has helped to address that concern.

What causes ED?

Risk factors for erectile dysfunction (ED) include underlying health issues such as:

• diabetes
• high blood pressure
• obesity
• high cholesterol
• chronic alcohol or drug abuse
• certain medications
• injuries.

Any condition that may restrict blood flow to veins over time, like smoking and normal aging, can lead to ED. Age alone is not a risk factor for ED, but underlying health issues can hasten its occurrence. Even though sexual dysfunction is more common in older men, it can also affect younger men (ages 18 to 25 years).

Medical conditions such as Parkinson's disease or Peyronie's disease (scar tissue build-up in the penis) may also cause ED.

Mental health issues can take their toll, too -- depression or stress can result in loss of libido. Erection failures may occur repeatedly in men who experience performance anxiety due to ED.

Do any medicines cause ED?

Many medications have impotence or sexual dysfunction listed as a side effect. Have your healthcare provider review your medications for this side effect to determine if any prescription or OTC drug treatment may be contributing to symptoms.

Medications that may lead to erectile dysfunction include:

• antidepressants (commonly the selective-serotonin reuptake inhibitors or the serotonin-norepinephrine reuptake inhibitors)
• blood pressure drugs
• certain antihistamines
• antipsychotics
• drugs used for benign prostatic hypertrophy (BPH)
• anti-HIV drugs.

If you regularly experience sexual function or ED problems, contact your doctor for evaluation and treatment.

How does Viagra work for ED?

Viagra works in response to sexual stimulation to increase the blood flow to the penis leading to an erection. Viagra does not result in an erection without sexual stimulation.

When a man is aroused, muscles in the penis relax to allow greater blood flow. Viagra helps to elevate the levels of a substance known as cyclic guanosine monophosphate (or cGMP) that causes the tissues to relax, leads to an inflow of blood, and causes an erection with sexual stimulation.

Viagra and other PDE5 inhibitors like Cialis, Stendra and vardenafil treat erectile dysfunction (ED), but do not directly increase a man's sexual desire.

However, knowing that one can perform better in bed may indirectly boost libido. Several of these agents are now available generically, too, which can help save dollars.

Related: See reviews and ratings for Viagra

How do you take Viagra?

Does Viagra have side effects?

In general, the most common side effects with PDE5 inhibitors like Viagra are mild and short-lived.

Side effects may include:

• Headache
• Flushing
• Heartburn
• Vision problems (blurry vision, light sensitivity)
• A blue-green tinge to your vision (usually a temporary side effect)
• Nausea
• Dizziness

Report a sudden hearing or vision loss to your healthcare provider immediately. An erection lasting more then 4 hours (priapism) is a rare event, but if it occurs get emergency treatment right away.

Be sure to review Viagra side effects with your healthcare provider prior to use.

What are other options for erectile dysfunction?

The simplicity of taking an oral tablet for erectile dysfunction has revolutionized ED treatment.

However, PDE5 inhibitors may not work in about 30% of men. It is important for men to know that there are other options available for ED. These solutions were used prior to Viagra, and are still available today:

• Penile self-injection (Caverject)
• Transurethral suppositories (MUSE)
• Vacuum-assisted erection devices
• Surgical penile prostheses

These options may be useful for some; however, for many men they can be complicated, uncomfortable, and more expensive. Be sure to talk to your doctor about all options.

To keep up with the latest news and developments, consider joining the Q & A Erection Support Group to get support from people with similar concerns.

What is "Low T"?

Media advertising has dramatically -- and sometimes sensationally -- increased the awareness of "Low-T" or low blood testosterone (also called androgen deficiency).

• Taking testosterone provides no benefit in improving a man's sexual function if their testosterone levels are normal.
• Men with low blood testosterone levels may suffer from a lower sex drive, erectile dysfunction (ED), brittle bones (osteoporosis), low muscle mass and higher fat accumulation.
• Typically, a man's testosterone level is considered low if it's below 300 nanograms/deciliter.

Testosterone therapy is available in many forms to raise testosterone levels, including injection, gel, skin patch, spray or lozenge. However, in addition to heart risks, older men who take testosterone replacements may need to have regular prostate cancer screening tests. Plus, testosterone therapy currently carries a boxed warning of potential heart risks, mandated by the FDA.

A report on the Testosterone Trials in 788 men over 65 years old noted that testosterone therapy can possibly raise the risk of heart disease and stroke, and may not be safe in men with low-but-normal testosterone levels and no outward symptoms related to low T.

• These trials were a set of 7 year-long clinical trials in 788 men 65 years or older and with hypogonadism conducted at 12 sites across the United States.
• Overall, the Testosterone Trials showed that the volume of arterial plaque increased more in the testosterone-treated group compared to the untreated "control" group, which could increase the risk over time for heart attack or stroke.
• The trials showed a positive benefit for bone health, anemia, and sexuality, but experts stated that it's unlikely testosterone will be considered a first-line treatment for those conditions, as other more effective and well-established options are available. No improvement in cognitive function (memory) was seen.

How much does Viagra cost?

The cost for brand name Viagra 50 mg oral tablets is around $2,640 for a supply of 30 tablets, depending on the pharmacy you visit. Generic versions can be found for as low as $20, using a pharmacy discount coupon.

In December 2017 generic versions of Viagra became commercially available which has lowered the cost considerably. In general, if you are paying with cash (not insurance) generic Viagra 50 mg (called sildenafil) runs about $20 per 15 tablets using an online coupon. Know that these prices can vary based on the pharmacy, the coupon and your location. So be sure to check for price differences.

• Pfizer offers significant savings, up to 50% off for the brand name product, if you prefer.
• Online coupons can be found for brand name Viagra and its generic in the Drugs.com Price Guide, too.
• But beware, much of the advertised Viagra on the Internet is counterfeit, and may even contain dangerous and toxic drugs.

Luckily, other erectile dysfunction drugs like Cialis (tadalafil) and vardenafil are available generically, but prices can vary, so ask your pharmacist.

Is counterfeit Viagra a worry? 

Viagra has become the victim of Internet fraud due to its rapid success and famous name.

According to Pfizer, 80% of the top 22 Internet sites that came up in search results for the phrase "buy Viagra" were selling counterfeit pills.

Products sold as "natural" or "herbal" Viagra claim to enhance performance; however, these illegal products have not undergone FDA review or approval. Fraudulent Viagra products contain unknown chemical ingredients that may pose a serious health risk.

Upon testing the counterfeit Viagra, Pfizer found these chemicals in the illegal drugs:

• blue printer ink
• amphetamines, also known as “speed”
• metronidazole, a powerful antibiotic that could cause an allergic reaction, diarrhea, or vomiting
• too much active ingredient (or not enough), which may cause you harm
• binding agents, such as drywall, that prevent the tablet from breaking down in your system.

Is Viagra approved for women?

No, Viagra is not approved for women. But there are other FDA-approved options, like Addyi, Osphena, Intrarosa, Imvexxy and Vyleesi.

More than 50 million women experience some type of sexual dysfunction. Studies looking at Viagra in women have theorized that sildenafil could increase genital blood flow and boost arousal. However, most studies have found a limited beneficial effect of Viagra for women. Lack of sex drive in a woman is a complicated process, often magnified by stress, hormonal changes, or lack of intimacy.

Medications to help boost libido and address other sexual problems in women are available.

• Addyi (flibanserin) was approved in August 2015 to treat low sex drive -- generalized hypoactive sexual desire disorder (HSDD) in pre-menopausal women. Addyi is not indicated to enhance sexual performance.
• Osphena (ospemifene), as well as Intrarosa (prasterone) are available for vaginal dryness and dyspareunia (painful intercourse) that can interfere with sex in menopausal women.
• In May 2018, Imvexxy (estradiol vaginal insert) was also approved for females who experience painful sexual intercourse.
• In June 2019, Vyleesi (bremelanotide) subcutaneous (under the skin) self-injection was approved to treat low sexual desire in women who have not gone through menopause and have not had low sexual desire in the past. Vyleesi is the second female libido drug to gain FDA approval after Addyi (flibanserin) in 2015; however, with Vyleesi, there is no warning for combined alcohol use.

Related: Vyleesi vs Addyi: What is the difference?

What are the generic options for erectile dysfunction (ED)?

In addition to sildenafil, the generic option for Viagra, other generic options used for the treatment of erectile dysfunction are now available at the pharmacy. These include:

• tadalafil (generic for Cialis)
• vardenafil
• The Levitra and Staxyn brands of vardenafil have been discontinued in the U.S.

For most men interested in cost-savings, switching to the generic forms may be a good option if they use the brand Stendra (avanafil). Generic options for this brand are not yet on the market. Ask your doctor about switching, if you prefer. See Stendra pricing and coupons here.

If you prefer not to switch to the generic, be sure to check with the manufacturer of the product you use to determine if they have discount programs that might help save you some money.

Related: Drugs.com Pricing and Coupon Guide

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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