Buy omeprazole no prescription sildenafil affects the response to sexual stimulation. It acts by enhancing smooth muscle relaxation using nitric oxide, a chemical that is normally released in response to sexual stimulation. This smooth muscle relaxation allows increased blood flow into certain areas of the penis, which leads to an erection. In case you notice any side effects not listed above, contact your doctor or pharmacist. Super P-Force cannot be used in patients with allergy to the medication and its components and also in individuals treated with nitrates (such as nitroglycerin). This combination can cause very low blood pressure potentially dangerous to result in a stroke, heart attack, or death. Do not take this medication if you are under 18 y.o.