Medicines that you take by mouth are called oral medicines. This development was credited largely “due to the introduction of generic products. New Zealand Sildenafil was reclassified in New Zealand in so it could be bought over the counter from a pharmacist. It is thought that this reduced sales over the Internet and was safer as males could be referred for medical advice if appropriate. Key facts It usually takes 30 to 60 minutes for sildenafil to work for erectile dysfunction. Sildenafil for pulmonary hypertension can also be known by the brand names Revatio and Grandipam.Lemonaid Sildenafil Best price for generic Viagra when bought in bulk: Optum Store Sildenafil If you are experiencing the symptoms of erectile dysfunction (ED), you may . How does Viagra work? Viagra is used to treat erectile dysfunction (ED). It decreases ED symptoms by helping you get and keep an erection. Sildenafil (Viagra) About sildenafil (Viagra) Sildenafil is a medicine used to treat erection problems (erectile dysfunction). Sildenafil is also sometimes used to treat pulmonary .