Viagra (Sildenafil) is an approved medicine for the treatment of men who have difficulty having and maintaining an erection (male impotence). Viagra can help you get firmer, longer-lasting and hard erections enabling you to have better sex with your partner. Remember, Viagra requires sexual desire or stimulation before it can work, it does not create it. How Viagra Works? An erection is the result of an increase in blood flow into certain internal areas of the penis. Viagra enhances the effects of one of the chemicals the body normally releases into the penis during sexual arousal. This allows an increase of blood flow into the penis. Viagra widens the blood vessels in your penis. This lets more blood flow into your penis. The blood fills the spaces in your penis, making it firmer. Viagra Dosage Viagra is available as oral tablets in 50mg and 100mg strengths.Viagra is taken orally (maximum once per twenty-four hour period) about one hour before sexual activity. For more detailed information consult with your Doctor. The effects of Viagra can last up to 4 hours. When Viagra is taken with a high fat meal, the rate of effectiveness is reduced. Viagra Side Effects As with any drug products, there are side effects of the product in some people. The most commonly reported side effects in patients treated with Viagra are: headache, flushing, stomach ache, urinary tract infection, diarrhoea, dizziness, rash, and mild and temporary visual changes (colour perception changes, light perception changes, and blurred vision). Stomach ache and abnormal vision were more common at 100 mg than at lower doses. How to Buy Viagra? You need a doctor's prescription for Viagra. You can buy Viagra from internet as well making sure you are buying it from a legitimate online clinic. An online clinic gets you through a series of medical questions – passes these details to one of their onboard UK Doctor and on approval, sends you the genuine medicine through a UK Pharmacy. Only buy Viagra made by Pfizer, there are many counterfeit products claiming to be Viagra that don't work. Counterfeit products can be really dangerous for your health. Male Impotence Treatment at Medical Specialists Medical Specialists is an authentic name in UK prescription medicine companies and provides prescription based treatments online with a free next day delivery. Visit Medical Specialists web site for more information.