Viagra was the first medicine to treat Erectile Dysfunction. It should be taken at least 45 minutes to one hour before sexual intercourse. The effect of medicine lasts mostly for four hours. Most men buy Viagra to treat ED even while having a wide range of medical problems, including those with a history of coronary artery disease, hypertension, peripheral vascular disease, diabetes, depression, radical prostatectomy and spinal cord injuries.

Levitra enhances the actions of the chemical messengers responsible for producing an erection, this means that sexual stimulation is required for it to produce and maintain an erection. When you buy Levitra, take it at least an hour before you intend to have intercourse. Levitra produces an erection in response to sexual stimulation up to five hours after taking it.

Cialis is known as weekend pill due to its 36 hour effect. This implies that you don’t have to schedule your lovemaking after taking the pill. You can play it cool, take your own time, get your partner into the mood and then slowly start your sexual activity. When you buy Cialis there is no pressure of time and you can have a peaceful and natural experience. However, one may have qualms about being under the influence of medicine for so long.