Injections: Injections are a reliable way to restore testosterone levels, but this therapy requires periodic injections (usually every two weeks) to sustain an effective level. It also causes high hormone levels right after the injection and low hormone levels just before the next shot. This is thought to be slightly more risky than other methods that maintain a moderate hormone level throughout the treatment period.
It appears that testosterone has NOS-independent pathways as well. In one study, castrated rats were implanted with testosterone pellets and then divided into a group that received an NOS inhibitor (L-nitro-L-arginine methyl ester [L-NAME]) and a control group that received no enzyme.  The castrated rats that were given testosterone pellets and L-NAME still had partial erections, a result suggesting the presence of a pathway independent of NOS activity.
Recently, the US Food and Drug Administration (FDA) has issued a safety announcement regarding TRT. In part it reads ‘The benefit and safety of these medications have not been established. We are also requiring these manufacturers to add information to the labeling about a possible increased risk of heart attacks and strokes in patients taking testosterone.’37
And surgery comes with its own serious risks, such as developing incontinence or impotence, while radiation can result in urinary problems. — Peter Loftus, WSJ, "Surgery Adds Three Years to Lives of Prostate-Cancer Patients, Study Finds," 12 Dec. 2018 Male-impotence pill Viagra began facing generic competition late last year, while the Lyrica pain treatment is expected to confront generics at the end of this year. — Jonathan D. Rockoff, WSJ, "Pfizer Narrows Guidance on Tougher Pricing, Generic Competition," 30 Oct. 2018 Arkham Horror Third Edition is a classic struggle of agency versus impotence, set in the uncanny world of H.P. Lovecraft’s Cthulhu mythos. — Charlie Theel, Ars Technica, "Arkham Horror Third Edition: The classic Lovecraft adventure returns," 24 Nov. 2018 There’s obviously a lot of anger and frustration here toward the US government at the moment—along with side effects like bottled rage and sometimes a creeping sense of ineptitude or impotence about our ability to do anything about it. — Corey Seymour, Vogue, "Pussy Riot's Nadya Tolokonnikova On Her New Guide To Activism, Raising The Next President Of Russia, And Her "Holy War" On Fairy Tales," 12 Oct. 2018 In exchange for political impotence, they would be mostly left alone and allowed to get rich. — Paul Mozur, New York Times, "Inside China’s Dystopian Dreams: A.I., Shame and Lots of Cameras," 8 July 2018 Their suspicion is compounded by rumors that the polio vaccine causes impotence, death and, ironically, paralysis. — Meher Ahmad, New York Times, "Pakistan Has Just One New Polio Case, but Isn’t Declaring Victory Yet," 20 May 2018 Fighting back, even as an exercise in impotence, did a lot for McCain. — Alex Horton, Washington Post, "John McCain rebelled at the Naval Academy — and as a POW — long before he was a Senate maverick," 3 May 2018 Feelings of desperation and impotence are being felt throughout Central America, where the lawlessness, endemic poverty and levels of gang violence akin to war zones that have driven so many families from their homes show little signs of abating. — Washington Post, "Violence keeps Central Americans coming to US despite Trump," 21 June 2018
Erectile dysfunction can occur as a side effect of medication taken for another health condition. Common culprits are high blood pressure meds, antidepressants, some diuretics, beta-blockers, heart medication, cholesterol meds, antipsychotic drugs, hormone drugs, corticosteroids, chemotherapy, and medication for male pattern baldness, among others.
Erectile dysfunction may be an unpleasant condition that no one really wants to talk about, failing to acknowledge it won’t make the problem go away. Your best defense against health problems like this is to learn everything you can about it so you can tackle the problem at the root. If you’re ready to stop living in embarrassment about your sexual function, become an advocate for yourself and your own health and talk to your doctor.
When you become aroused, your brain sends chemical messages to the blood vessels in the penis, causing them to dilate or open, allowing blood to flow into the penis. As the pressure builds, the blood becomes trapped in the corpora cavernosa, keeping the penis erect. If blood flow to the penis is insufficient or if it fails to stay inside the penis, it can lead to erectile dysfunction.
Factors that mediate contraction in the penis include noradrenaline, endothelin-1, neuropeptide Y, prostanoids, angiotensin II, and others not yet identified. Factors that mediate relaxation include acetylcholine, nitric oxide (NO), vasoactive intestinal polypeptide, pituitary adenylyl cyclase–activating peptide, calcitonin gene–related peptide, adrenomedullin, adenosine triphosphate, and adenosine prostanoids.
Sildenafil is available as oral tablets at doses of 25 mg, 50 mg, and 100 mg. Patients should take sildenafil approximately one hour before sexual activity. In some men, the onset of action of the drug may be as early as 11-20 minutes. It's best for men to take sildenafil on an empty stomach for best results since absorption and effectiveness of sildenafil can be diminished if it is taken shortly after a meal, particularly a meal that is high in fat. Sildenafil and the other PDE5 inhibitors don't cause an immediate erection. Sexual stimulation is necessary for these medications to work.
When it comes to boosting sexual performance, many men will walk all over God’s green earth looking for ways to maintain a good sex life. Luckily men, all you have to do is walk — not run — 2 miles a day. This, along with other healthier lifestyle interventions can help obese men reduce their risk of ED, or even “reverse” current impotence, according to a 2005 study. This comes of importance, since maintaining a trim waistline is a good defense for ED, as men with a 42-inch waist are 50 percent more likely to have ED than those with a 32-inch waist. Getting to a healthy weight and maintaining it is a good strategy for preventing and treating ED.
The main surgical treatment of ED involves insertion of a penile implant (also called penile prostheses). Because penile vascular surgery is not recommended for aging males who have failed oral PDE5 inhibitors, ICI or IU therapies, implants are the next step for these patients. Although placement of a penile implant is a surgery which carries risks, they have the highest rates of success and satisfaction among ED treatment options.