Box , Mission, KS If your pharmacy does not participate, you may be able to submit a request for a rebate in connection with this Savings Offer. In order to purchase Viagra Connect over the counter, you will be required to fill out a medical questionnaire which will be reviewed and authorised by the pharmacist. No side effects were reported in sexual partners. These small differences affect the way each medication works, such as how quickly it takes effect and wears off, and the possible side effects. This medicine works best when you take it on an empty stomach an hour before sex.Written by. The Manual Team. Medically approved by. Dr Earim Chaudry. Last updated. 14th July Manual Health Centre. See your GP for a prescription. A prescription . In fact, a recent review of studies found that some counterfeit drugs contained a very high, dangerous level of sildenafil that far exceeded a typical prescription . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes muscles .