Sildenafil

PDE-5 inhibitor
PRESCRIPTION ONLY IN INDIA

Sildenafil is a pDE-5 inhibitor found in 11 medicines sold in India, such as Manforce 50, Manforce 100, Penegra 50. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.

What it is used for

Treats erectile dysfunction; also used for pulmonary hypertension.

How it works

A PDE-5 inhibitor that increases blood flow, used for erectile dysfunction and, at other doses, for lung blood pressure (pulmonary hypertension).

How to take it

For erections: 25 to 100 mg about 1 hour before sex, no more than once a day; works only with sexual stimulation. A heavy meal delays it.

Common side effects

  • Headache
  • Flushing
  • Stuffy nose
  • Indigestion
  • Bluish vision

Get medical help straight away if

  • Erection lasting more than 4 hours
  • Sudden loss of vision or hearing
  • Chest pain during sex

Be careful

Never take with nitrate heart medicines (dangerous drop in BP). Seek help for an erection lasting over 4 hours.

Other medicines and interactions

Never take with nitrates (isosorbide, glyceryl trinitrate, nicorandil) or riociguat; dangerous fall in blood pressure. Caution with alpha blockers. Ritonavir and some antifungals raise levels.

Pregnancy and breastfeeding

Not relevant for erectile use; used in pregnancy only for specific lung conditions under specialists.

Brands of Sildenafil (11)

Caverta 50Eriacta 50Intagra 50Kamagra Gold 50Macsutra 50Manforce 100Manforce 50Penegra 50Suhagra 50Viagra 50Vigore 50 Red

Common questions

What is Sildenafil used for?

Treats erectile dysfunction; also used for pulmonary hypertension.

How does Sildenafil work?

A PDE-5 inhibitor that increases blood flow, used for erectile dysfunction and, at other doses, for lung blood pressure (pulmonary hypertension).

How should I take Sildenafil?

For erections: 25 to 100 mg about 1 hour before sex, no more than once a day; works only with sexual stimulation. A heavy meal delays it.

What are the side effects of Sildenafil?

Common: Headache, flushing, stuffy nose, indigestion, bluish vision. Get help straight away for: Erection lasting more than 4 hours, sudden loss of vision or hearing, chest pain during sex.

Does Sildenafil interact with other medicines?

Never take with nitrates (isosorbide, glyceryl trinitrate, nicorandil) or riociguat; dangerous fall in blood pressure. Caution with alpha blockers. Ritonavir and some antifungals raise levels.

Is Sildenafil safe in pregnancy and breastfeeding?

Not relevant for erectile use; used in pregnancy only for specific lung conditions under specialists.

Does Sildenafil need a prescription in India?

Yes. In India it is a prescription (Schedule H) medicine, so a pharmacist should sell it only with a doctor's prescription.

Which brands contain Sildenafil?

Caverta 50, Eriacta 50, Intagra 50, Kamagra Gold 50, Macsutra 50, Manforce 100, Manforce 50, Penegra 50, Suhagra 50, Viagra 50, Vigore 50 Red.

Sources and further reading

NHS (UK National Health Service) and MedlinePlus (US National Library of Medicine) are free, reviewed medicine guides. Brand names and doses there may differ from India.

Last reviewed 31 October 2026. Written by Satya Babu from standard prescribing information.

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For information only, not medical advice. This page is a plain-language summary written from standard prescribing information and the public guides linked below. Brands sometimes change their formula, so always check the composition printed on the pack. Doses here are typical adult doses; yours may differ. Do not start, stop or change a medicine without your doctor or pharmacist, and keep all medicines away from children. In an emergency, call 112 (India) or your local emergency number.