You get Viagra (Pfizer's sildenafil citrate) at a medical store
on prescription of doctor. The doctor who is authorized to
prescribe, example a Urologist or Psychiatrist, differs in
different countries. In India only a Psychiatrist can prescribe. In
most countries in Asia (as in India) where regulations for sale of
drugs is poorly implemented Viagra is available across the counter
in a medical store without a doctor's prescription.