Introduction to online and generic Viagra, cialis and levitra.

Erectile dysfunction or impotence is a very common problem in males ages 30 and up. During 1998 the company Pfizer introduced Viagra, which was already tested and FDA approved to be sold in the United States of America, and in the incredible boom of impotence pills for men arose other generic medications competitors like tadalafil also known as Cialis, and vardenafil also known as Levitra. All of these medications contain the active ingredient Sildenafil Citrate, which is what gives impotent men a lasting erection.

Viagra was actually created to treat a condition by the name of angina, but during the medical studies erections were observed as a side effect of the treatment with Sildenafil Citrate. It all started at Pfizer's England study center named Kent, where Sildenafil was first synthesized. In 1996 Viagra was first pill approved to treat male impotence, erectile dysfunction or erection problems. To develop this incredibly successful drug scientists studied more than 1500 different compounds and spent an estimated $750 million. It took 13 years to bring Viagra from conception to production.

Pfizer’s Viagra sales in the year 2000 accounted for almost 92% of the global market for impotence or erection medications. By the year 2007 Viagra’s global share had plunged to about 50 because of the introduction of the generic version known as Cialis and Levitra, along with several other counterfeits and clones, which is the reason why you should only buy the pills from your trusted and secure online pharmacy like xlpharmacy.com

Sildenafil Citrate, Viagra, Levitra, Cialis, "Vitamin V", "the Blue Pill", or however producers call it is available by prescription from a doctor. Many drug stores and online pharmacies offer Viagra for sale after an online consultation, often a simple web questionnaire that’s latter evaluated. The Viagra name has become so well known that many fake aphrodisiacs now call themselves herbal Viagra or are presented as blue tablets imitating the shape and color of Pfizer's product.

Viagra or more specifically Sildenafil is a inhibitor of specific phosphodiesterase type 5 which has to degrade cGMP in the penis. The molecular structure of sildenafil is very similar to cGMP and will bind as an agent of PDE5 in the penis, resulting in more cGMP and better, longer lasting erections. It’s supposed that without sexual stimulation sildenafil should not cause an erection, however there have been reports of rise in libido and desire, which in turns does lead to the erection without sexual intercourse. Other drugs that operate by the same mechanism include tadalafil (Cialis) and vardenafil (Levitra).

Sildenafil made by the metabolisation of hepatic enzymes and excreted by both the liver and kidneys. Its better to take Viagra or any other impotence, sexual dysfunction or erection medication not with a full stomach, as this will delay the effect and lessen the peak of the Sineldafil Citrate.         Next Viagra Article >>