a b c d e Smith KM, Romanelli F (2005). "Recreational use and misuse of phosphodiesterase 5 inhibitors". Journal of the American Pharmacists Association. 45 (1): 63–72, quiz 73–5. doi: 10.1331/1544345052843165. PMID 15730119.

Constriction rings work by keeping the penis erect and can help men who find it hard to keep an erection, rather than get one in the first place. The ring is placed around the base of the penis, this traps blood in the erect penis, making it harder to lose an erection. Psychological treatment Generally, Viagra lasts around four hours. So it’s important you don’t take Viagra too long before you want to have sex, for example don’t take Viagra in the morning if you expect to have sex at night. It’s likely if you leave it that long, the effects of Viagra will have worn off. How effective is Viagra? Acetildenafil and other synthetic structural analogs of sildenafil which are PDE5 inhibitors have been found as adulterants in a number of "herbal" aphrodisiac products sold over-the-counter. [41] These analogs have not undergone any of the rigorous testing that drugs like sildenafil have passed, and thus have unknown side-effect profiles. [42] Some attempts have been made to ban these drugs, but progress has been slow so far, as, even in those jurisdictions that have laws targeting designer drugs, the laws are drafted to ban analogs of illegal drugs of abuse, rather than analogs of prescription medicines. However, at least one court case has resulted in a product being taken off the market. [43] Teva Canada launched Novo-Sildenafil, a generic version of Viagra, on the day the Supreme Court of Canada released its decision. [90] [91] [92] To remain competitive, Pfizer then reduced the price of Viagra in Canada. [93] However, on 9 November 2012, Pfizer filed a motion for a re-hearing of the appeal in the Supreme Court of Canada, [94] on the grounds that the court accidentally exceeded its jurisdiction by voiding the patent. [95] Finally, on 22 April 2013, the Supreme Court of Canada invalidated Pfizer's patent altogether. [96] ChinaProfessional athletes have been documented using sildenafil, believing the opening of their blood vessels will enrich their muscles. In turn, they believe it will enhance their performances. [39] [40] Analogs a b c Roustit M, Blaise S, Allanore Y, Carpentier PH, Caglayan E, Cracowski JL (October 2013). "Phosphodiesterase-5 inhibitors for the treatment of secondary Raynaud's phenomenon: systematic review and meta-analysis of randomised trials". Annals of the Rheumatic Diseases. 72 (10): 1696–9. doi: 10.1136/annrheumdis-2012-202836. PMID 23426043. S2CID 33666968. PDE-5 inhibitors appear to have significant but moderate efficacy in secondary [Raynaud's phenomenon]. Sildenafil, sold under the brand name Viagra, among others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension. [4] [8] It is also sometimes used off-label for the treatment of certain symptoms in secondary Raynaud's phenomenon. [9] It is unclear if it is effective for treating sexual dysfunction in females. [8] It can be taken orally (swallowed by mouth), intravenously (injection into a vein), or through the sublingual route (dissolved under the tongue). [8] [10] Onset when taken orally is typically within twenty minutes and lasts for about two hours. [8] suggest the tests you should get and can prescribe medicine to help; providing it’s suitable for you. Research". ABM. Abertawe Bro Morgannwg University Health Board. 4 July 2008. Archived from the original on 26 September 2008 . Retrieved 6 August 2008. Our clinicians regularly offer patients the opportunity to take part in trials of new drugs and treatments. Morriston Hospital in Swansea, was the first in the world to trial Viagra!

Food: Eating a heavy meal, particularly one with lots of high-fat foods, just before taking Viagra can make the drug slower to take effect. The body takes longer to absorb the drug when it’s busy metabolising food. Like the ‘blue pill’ there’s a few other names used to refer to different erectile dysfunction treatments, including: Eardley I, Ellis P, Boolell M, Wulff M (2002). "Onset and duration of action of sildenafil for the treatment of erectile dysfunction". British Journal of Clinical Pharmacology. 53 (Suppl 1): 61S–65S. doi: 10.1046/j.0306-5251.2001.00034.x. PMC 1874251. PMID 11879261. Busbee J (28 November 2012). "Bears' Brandon Marshall says some NFL players use Viagra … ON THE FIELD". Yahoo! Sports. Archived from the original on 5 March 2016 . Retrieved 28 November 2012.

Nichols DJ, Muirhead GJ, Harness JA (6 March 2002). "Pharmacokinetics of sildenafil after single oral doses in healthy male subjects: absolute bioavailability, food effects and dose proportionality". British Journal of Clinical Pharmacology. 53 (Suppl 1): 5S–12S. doi: 10.1046/j.0306-5251.2001.00027.x. PMC 1874258. PMID 11879254.

Mental/emotional wellbeing: Many men experience worry and performance-anxiety when beginning ED treatment for the first time, and this is completely natural. So for some men additional support such as counselling might be necessary to maximise treatment success.

Do any medicines cause ED?

Spedra: As the name suggests, Spedra is the fastest acting ED medication. It should be taken about 15 minutes before sex Cialis - An almond-shaped yellow pill, Cialis is the most expensive ED medication but also the longest lasting. Cialis remains active for up to 36 hours.