Viagra Tablet Uses: How It Works, Side Effects and Price in India

The main viagra tablet uses are simple: Viagra is the brand name of sildenafil, a prescription medicine that helps men with erectile dysfunction (ED) get and keep an erection firm enough for sex. It works only when you are sexually aroused, usually starts within 30 to 60 minutes, and does not treat the cause of ED.

This guide covers how the tablet works, how long it lasts, side effects, who should avoid it, how it compares with tadalafil, what drives its cost in India, and the questions Indian men ask us most.

First, a word of reassurance. Erection problems are very common: 1 in 4 men struggle with ED and PE (see how common erectile dysfunction is in India). Needing help is not a sign of weakness, and ED is treatable. The best results come when a doctor looks at why it is happening, not just at which tablet to take, which is why this post sits within our wider guide to erectile dysfunction causes and treatment.

What is a viagra tablet used for?

A viagra tablet is used to treat erectile dysfunction, which means trouble getting or keeping an erection hard enough for satisfying sex, by improving blood flow into the penis during arousal. Under a different brand and schedule, the same medicine also treats a lung blood-pressure condition called pulmonary arterial hypertension.

ED used to be called impotence. Today doctors prefer the term erectile dysfunction because it describes what is happening, a blood-flow and nerve response problem, without the shame attached to the old word. Viagra was the first tablet approved for it, by the US Food and Drug Administration in 1998, and it changed how the condition is treated around the world.

Here is what the tablet can and cannot do for men:

• It can help you get a firmer erection and keep it long enough for sex, when you are aroused.
• It can reduce the performance anxiety that builds up after a few "failures", because erections become more reliable.
• It cannot create sexual desire. If you have no interest in sex, the tablet will not change that.
• It cannot increase penis size, cure ED permanently or fix the health problem behind it.
• It is not approved to delay ejaculation. Premature ejaculation (PE) is a different condition with different treatments.

Is sildenafil the same as viagra? Indian brand names explained

Yes. Sildenafil citrate is the medicine (the "salt", as chemists in India call it), and Viagra is the original brand name made by Pfizer. Once the patent protection ended, many Indian pharmaceutical companies began selling sildenafil under their own brand names. Manforce and Suhagra, two names people often search for, contain the same sildenafil citrate.

So if you see "sildenafil citrate tablets IP" on a strip, that is the same active medicine as Viagra. The brand changes the price and the packaging, not how the medicine works in your body. What still matters is whether sildenafil is safe for you and which strength suits you, and that is a decision for a doctor.

Sildenafil for pulmonary arterial hypertension

Sildenafil is also prescribed for pulmonary arterial hypertension (PAH), a serious condition in which blood pressure in the lungs is too high. It affects people of any sex, including women. For PAH it is sold under a different brand (Revatio) and taken on a regular schedule set by a specialist, not before sex. This is never something to treat on your own.

How does viagra work and how long does it last?

Sildenafil blocks an enzyme called PDE5, which lets the blood vessels in the penis relax and fill with blood when you are sexually excited. It usually starts working in 30 to 60 minutes and helps for about 4 hours, but it does not cause an erection on its own.

An erection is really a blood-flow event. When you are aroused, nerves release chemical signals that relax the smooth muscle in the penis. Blood rushes in, the spongy tissue swells and the veins that normally drain blood out get squeezed shut. PDE5 is the enzyme that ends this process. By slowing PDE5 down, sildenafil helps the relaxed, blood-filled state last long enough for sex.

Why it only works with sexual arousal

Many men worry that taking the tablet will give them an erection that will not go away, at work or in front of family. That is not how it works. Sildenafil only strengthens a response that has already started. Without arousal, touch or desire, nothing much happens. This is also why the tablet can seem to "fail" when a man is very anxious, exhausted or not in the mood: the starting signal is missing.

How long does viagra take to work and how long does it last?

According to the US prescribing information, sildenafil is usually taken about an hour before sex, and most men notice an effect somewhere between 30 minutes and 4 hours after taking it. The useful window is roughly 4 hours. That does not mean a 4-hour erection. It means that during those hours, you can get an erection more easily when you are aroused, and it will subside normally after sex.

Some traces of the medicine stay in the body for longer. The NHS guide to sildenafil says the useful effect is about 4 hours. Traces stay longer, so take it no more than once in 24 hours. The 36-hour window belongs to tadalafil, not Viagra.

A few things change how quickly it works:

• A heavy, oily meal (think biryani, parathas with butter, fried snacks) can delay the effect.
• Alcohol in larger amounts makes erections harder and side effects worse.
• Anxiety can cancel out the effect, especially the first time.
• Grapefruit juice can raise the level of the medicine in your blood and increase side effects.

How is the right strength chosen?

Sildenafil tablets come in several strengths, and in India you will see many different packs. A higher strength is not "stronger sex". It mainly raises the chance of side effects. The right strength depends on your age, your other health conditions, the medicines you already take and how your liver and kidneys work, so it should be chosen by a doctor, not by a friend or the chemist. Whatever the strength, it is taken at most once in 24 hours.

A heart medicine that became an ED treatment

Sildenafil was first developed by Pfizer scientists in the late 1980s as a possible treatment for angina (chest pain from heart disease). It did not work well for the heart, but men in the trials reported better erections. After further studies, the FDA approved it for erectile dysfunction in 1998. It remains one of the most studied medicines in men's health, which is why doctors understand its benefits and risks so well.

What causes the erection problem viagra treats?

ED is rarely just "weakness": it usually has a specific cause, such as diabetes, high blood pressure or cholesterol, low testosterone or thyroid problems, stress, anxiety and poor sleep, or habits such as smoking, alcohol and gutkha. Viagra helps the erection for a few hours; treating the cause is what helps long term.

This is the part most pharmacy pages skip, and it is the most important idea in this guide. Two men can walk into a clinic with exactly the same complaint and need completely different treatment. For a full picture, read our guide to what causes erectile dysfunction and how it is treated. In short, the common root causes are:

Blood vessel and metabolic causes

• Diabetes: high sugar damages the small blood vessels and nerves the penis depends on. Read more about diabetes and erection problems.
• High blood pressure and high cholesterol: they stiffen and narrow arteries, so less blood reaches the penis.
• Weight around the belly: linked with lower testosterone and poorer blood flow.

Hormonal causes

• Low testosterone: often shows up as low desire, tiredness and weaker erections. Sildenafil does not fix this. If tablets are not working well, a doctor may check your hormones; learn the signs of low testosterone.
• Thyroid problems: both an underactive and an overactive thyroid can affect erections and desire.

Mind and lifestyle causes

• Stress, anxiety and depression: work pressure, money worries, marriage pressure or one bad night can start a cycle of performance anxiety.
• Poor sleep: short or broken sleep lowers testosterone and energy.
• Smoking, gutkha and chewing tobacco: nicotine narrows blood vessels. See how chewing tobacco affects erections.
• Alcohol: regular or heavy drinking dampens both nerves and hormones.

There is one more reason this matters. Because the arteries of the penis are narrower than the arteries of the heart, erection problems can appear years before a heart problem does. In a man in his 30s or 40s, new ED can be an early warning sign worth checking with a doctor, not just a bedroom issue to cover with a tablet.

Lifestyle changes help many men alongside any medicine: regular exercise, better sleep, cutting down alcohol and tobacco, and a balanced diet. Our guide to foods that support healthy erections lists everyday Indian options.

Not sure what is behind your erection problems? Before reaching for a pill, take the free Men's Test. It takes about 2 minutes, it is completely private, and it helps a doctor understand your likely root cause.

What are the side effects of viagra, and who should not take it?

Common side effects are headache, facial flushing, a blocked nose, indigestion, dizziness and short-lived changes in vision. Sildenafil is unsafe with nitrate medicines for chest pain, and anyone with a recent heart attack or stroke, very low blood pressure, or serious liver or kidney disease needs a doctor's clearance first.

Most side effects are mild and fade as the medicine wears off. Serious reactions are uncommon, but you should know what they look like so you can act quickly.

Common side effects

• Headache
• Flushing (a warm, red face or neck)
• Blocked or runny nose
• Indigestion or an upset stomach
• Dizziness
• Back or muscle aches
• Temporary changes in vision, such as blurring, sensitivity to light or a blue tinge to colours

Warning signs that need urgent medical help

Stop and get medical help straight away if you notice any of these:

• An erection lasting more than 4 hours, especially if it is painful (called priapism). It can damage the penis if it is not treated quickly.
• Sudden loss of vision in one or both eyes.
• Sudden loss of hearing or ringing in the ears.
• Chest pain, a tight feeling in the chest, an irregular heartbeat or fainting, particularly during or after sex.
• Signs of an allergic reaction, such as swelling of the face, lips or throat, or trouble breathing.

Medicines and conditions that do not mix with sildenafil

This is where self-medication becomes risky. According to the FDA prescribing information for Viagra and the NHS, sildenafil should not be taken, or needs special care, in these situations:

Situation	Why it matters	What to do
Nitrate medicines for angina (tablets or sprays under the tongue)	The combination can drop blood pressure to dangerous levels	Never combine; tell your doctor about every heart medicine
Riociguat (a lung blood-pressure medicine)	Similar risk of a sharp fall in blood pressure	Do not combine
"Poppers" (amyl nitrite)	Also nitrates, with the same blood-pressure risk	Do not combine
Alpha-blockers for prostate or blood pressure	Can cause dizziness or fainting when combined	Only with a doctor's plan
Recent heart attack or stroke, unstable angina, very low or uncontrolled high blood pressure	Sex and the medicine both put extra demand on the heart and circulation	Get a heart check first
Serious liver or kidney disease	The medicine is cleared more slowly	A doctor decides if it is suitable
Some HIV medicines and certain antifungals or antibiotics	They raise sildenafil levels in the blood	A doctor adjusts the plan
Past sudden vision loss from reduced blood flow to the optic nerve	Risk of it happening again	Usually avoided

If you take tablets for BP, you are not automatically ruled out. Many men with well-controlled blood pressure use sildenafil safely under supervision. Our guide to sildenafil with blood pressure medicines explains what to discuss with your doctor. The same goes for diabetes: it is a common reason for ED and usually not a reason to avoid treatment, but it does need a proper check.

Viagra vs tadalafil: which is better?

Neither is simply better: both are PDE5 medicines for ED, but sildenafil helps for about 4 hours while tadalafil (sold as Cialis and many Indian brands) lasts up to 36 hours. Tadalafil is also less affected by food and can be prescribed as a low daily tablet.

Indian men often search "viagra vs tadalafil" or "viagra vs Cialis" hoping for a winner. In practice, doctors choose based on your health, your routine and how you respond. Here is a side-by-side view:

Feature	Sildenafil (Viagra)	Tadalafil (Cialis)
Type of medicine	PDE5 inhibitor	PDE5 inhibitor
Usually taken	About 1 hour before sex	Before sex, or as a daily low-strength tablet
Starts working	About 30 to 60 minutes	About 30 minutes to 2 hours
Helpful window	About 4 hours	Up to 36 hours
Effect of a heavy meal	Can delay it	Little effect
Common side effects	Headache, flushing, blocked nose, vision changes	Headache, flushing, indigestion, back and muscle pain
Nitrate medicines	Must not be combined	Must not be combined
Prescription needed in India	Yes	Yes

Some men prefer tadalafil because the long window feels less planned and more spontaneous. Others prefer sildenafil because it clears faster. Tadalafil is also used for an enlarged prostate, which can suit some older men. Two other medicines in the same family, vardenafil and avanafil, exist too. Whichever one you use, it should come with a prescription and a check of your heart and blood pressure.

How much does viagra cost in India, and do herbal alternatives work?

Branded Viagra is expensive in India, while generic sildenafil costs a fraction of the price for the same medicine. Herbal "desi viagra" products, on the other hand, have no good evidence behind them.

Some herbal products even contain hidden drugs or heavy metals. Here is what Indian men should know before buying anything, whether it comes from a chemist, a website or a roadside clinic.

Viagra tablet price in India

Prices change with brand, strength and pack size, so we do not list them here. What drives the cost:

• Branded or generic. Branded Viagra from Pfizer costs far more than licensed Indian generics that contain the same sildenafil citrate.
• Strength and pack size. Larger packs usually cost less per tablet, but the strength should be set by a doctor, not by price.
• Where you buy. Buy only from a licensed pharmacy with a prescription. Roadside clinics and "gupt rog" quacks often charge more for less, or for fakes.

For Raaz consultation and plan pricing, see the Raaz MD plans page.

The medicine inside is the same sildenafil citrate. A cheaper licensed generic is not a weaker medicine, and the most expensive option is not automatically the safest. What matters more is that the strength is right for your body and that it comes from a licensed pharmacy.

Why very cheap tablets without a prescription are risky

Sildenafil is a prescription-only medicine in India, yet it is easy to find without one: from roadside "sex clinics", WhatsApp sellers, gym contacts and websites that never ask a single health question. The risks are real:

• Counterfeit tablets may contain too much, too little or none of the medicine, or something else entirely.
• No safety check means nobody asks whether you take nitrates, have heart disease or have very low blood pressure.
• The cause stays hidden. A tablet can mask diabetes, high BP or low testosterone for months while the underlying problem gets worse.

Common viagra myths in India

• "It increases size." No. It improves blood flow for an erection; it does not change the size of the penis.
• "It is a sex booster that increases desire." No. It works only when desire and arousal are already there.
• "Two tablets work better than one." No. More medicine means more side effects, not better sex. Never take more than prescribed.
• "Once you start, you can never stop." Sildenafil is not physically addictive. Some men come to rely on it for confidence, which is why treating the cause and any performance anxiety matters.
• "Only old men need it." ED also affects men in their 20s and 30s, often because of stress, anxiety, smoking or early metabolic problems. Read how erection problems change with age.

Do ayurvedic or herbal alternatives to viagra work?

Many Indian men try a herbal product first, often sold as "desi viagra", "shakti" capsules or "power" churans, because it feels safer and more private. Unfortunately, good-quality evidence that these products treat ED is missing, and some carry real risks.

Here is what research actually shows:

• Ashwagandha: in a randomised, placebo-controlled trial published in the Indian journal Ayu, ashwagandha worked no better than placebo for psychogenic erectile dysfunction.
• Heavy metals: a study in JAMA tested Ayurvedic products sold online and found lead, mercury or arsenic in about 1 in 5 of them (20.7%), including products made in India.
• Hidden medicines: some "herbal" sex products have been found to contain undeclared sildenafil or similar drugs. That means a man taking nitrates for his heart could be exposed to a dangerous combination without knowing it.
• Shilajit and safed musli: they are widely sold for stamina, but there are no reliable human trials showing they treat ED.

Liver specialist Dr. Cyriac Abby Philips (known online as TheLiverDoc) shared a post in July 2021 about Ayurvedic ED medicines prescribed to a patient. He pointed out that the patient was taking more than 20 tablets a day, that several herbs listed can be toxic, and that there was no evidence the combination worked.

This does not mean every traditional practice is harmful, or that you should feel foolish for trying one. It means "natural" is not the same as "proven" or "safe". If you are taking any herbal product, show the label to your doctor. Our complete erectile dysfunction guide, linked above, covers what the evidence says about ayurveda and ED in more detail.

Instead of paying for a raft of products one after another, it is usually cheaper and safer to find out what is really causing the problem. A doctor-led plan, if you need one, can be discussed after a consultation; you can see how Raaz MD's personalised plans work.

When should you see a doctor?

See a doctor before taking any ED tablet for the first time. Also see one if erection problems are frequent or started suddenly, if you have diabetes, BP, heart disease or chest pain, if you take other medicines or herbal products, or if tablets have stopped working.

Many men delay this step for months or years out of embarrassment. There is no need to. Doctors who treat sexual health talk about erections every day, and a good consultation is calm, private and practical. Book a consultation promptly if:

1. You have never been assessed for ED and are thinking of trying a tablet.
2. The problem came on suddenly or is getting worse over weeks or months.
3. You have diabetes, high blood pressure, high cholesterol or heart disease, or a family history of early heart disease.
4. You take nitrates, alpha-blockers or several other medicines, or you use any herbal or "power" product.
5. Sildenafil or tadalafil has not worked after a few proper attempts, or has stopped working.
6. You also have low desire, tiredness or mood changes, which can point to low testosterone, thyroid problems or depression.
7. You finish too early rather than losing the erection. That is PE, and it needs a different approach.

Go to an emergency department straight away if you have chest pain during or after sex, sudden loss of vision or hearing, or an erection that lasts more than 4 hours.

A good doctor will ask about your health, habits, stress and relationship, check your blood pressure, and may order simple blood tests such as sugar, cholesterol, thyroid and testosterone. Then the treatment, whether it includes a tablet or not, is matched to your cause.

So, is a viagra tablet right for you?

For many men, sildenafil is a safe and effective way to get erections back, as long as a doctor has checked it suits them. But it is a tool, not a cure: it works for a few hours; the root cause, whether it is sugar, blood pressure, hormones, stress or habits, is what decides how your sex life feels next year.

Raaz MD has carried out 50,000+ doctor consultations with Indian men facing exactly these questions, and "97% users saw results" with a plan built around their own cause. The first step is simple: take the free Men's Test. It takes about 2 minutes, it is private, and it points you towards the right treatment instead of guesswork.