Nowadays, can buy Viagra and Cialis online form sites like andsons and doctoroncall.
But the price not very cheap, so better go for twin/generic version such as IQNYDE for Viagra or Talis for Cialis. They both work the same.
Prescription will be given after online consultation.
In term of delivery, doctoroncall is better in my experience. You can get your item within a day or 2 days the most, after getting prescription/online consultation.

Having said that, if you prefer natural medication to get hard or maintain your hardness, can try Himalaya Tentex Royal.
It's quite potent, though take a longer time to show result compare to Viagra or Cialis, which is around 2 hours after consume.