You put your penis in the cylinder and start pumping. The suction creates a vacuum, so blood rushes in to fill the spaces in the spongy tissue of the penis, creating an erection. The erection lasts only as long as the blood stays in, so you slide the band down around the base of your penis, trapping the blood. It's safe to keep the band on for up to 30 minutes.
Apostolo A,  Vignati C,  Brusoni D,  Cattadori G,  Contini M,  Veglia F,  Magrì D,  Palermo P,  Tedesco C,  Doria E,  Fiorentini C,  Montorsi P,  Agostoni P. Erectile dysfunction in heart failure: correlation with severity, exercise performance, comorbidities, and heart failure treatment, J Sex Med , 2009, vol. 6 (pg. 2795-2805)https://doi.org/10.1111/j.1743-6109.2009.01416.x
Gutiérrez-González, Enrique; Castelló, Adela; Fernández-Navarro, Pablo; Castaño-Vinyals, Gemma; Llorca, Javier; Salas-Trejo, Dolores; Salcedo-Bellido, Inmaculada; Aragonés, Nuria; Fernández-Tardón, Guillermo; Alguacil, Juan; Gracia-Lavedan, Esther; García-Esquinas, Esther; Gómez-Acebo, Inés; Amiano, Pilar; Romaguera, Dora; Kogevinas, Manolis; Pollán, Marina; Pérez-Gómez, Beatriz. “Dietary Zinc and Risk of Prostate Cancer in Spain: MCC-Spain Study.” Nutrients. Jan 2019, 11(1).
Control your blood sugar through your diet. Eating a diabetes-friendly diet will help you better control your blood sugar levels and lessen the amount of damage to your blood vessels and nerves. A proper diet geared at keeping your blood sugar levels in check can also improve your energy levels and mood, both of which can help reduce the risk of erectile dysfunction. You may consider working with a dietitian who is also a certified diabetes educator to help adjust your eating style.

Abstract | Full Text | Full Text PDF | PubMed | Scopus (30) | Google ScholarSee all References Increased cGMP levels cause intracellular calcium levels to decrease, resulting in relaxation of the corporeal smooth muscle, active dilatation of the penile arteries, arterioles, and sinusoids, and finally, increased arterial inflow and passive compression of penile venous outflow.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
Some doctors prefer to start a man on the lowest dose of an oral medicine and increase the dose until an effective one is found. Others prefer to start with the highest dose and go to a lower dose only if a man complains of side effects. In either case, it’s important for a man to communicate with his doctor to let him know how the dose he’s using is working.
A follow-up study from the ExCEED database compared men with ED and prostate cancer to men with ED without prostate cancer and found that the prostate cancer survivors had worse erectile function but reported better quality of life than those without prostate cancer.37 The authors hypothesized that the prostate cancer survivors were able to “rationalize” away their sexual dysfunction with the knowledge that they may have been “cured” of their prostate cancer. Clearly, diabetic men could not use the same rationale.
Abstract | PubMed | Scopus (136) | Google ScholarSee all References Other candidate mechanisms linking ED and cigarette smoking include hypercoagulability and increased platelet aggregation, increased release of free fatty acids and catecholamines, changes in NO synthetic pathways, and a possible direct toxic effect on vascular endothelium.13x13Chung, WS, Shim, BS, and Park, YY. Hemodynamic insult by vascular risk factors and pharmacologic erection in men with erectile dysfunction: Doppler sonography study. World J Urol. 2000; 18: 427–430
The most important way to protect your heart is to eat a Nutritarian diet and that means eating your G-BOMBS: greens, beans, onions, mushrooms, berries and seeds. Natural plant foods have numerous cardio-protective effects. For example, greens activate the Nrf2 system, which turns on natural detoxification mechanisms and protects blood vessels against inflammatory processes that lead to atherosclerotic plaque buildup.9

For oral erectile dysfunction medicines to work as desired, they must be used properly in the first place. This means taking the medicine 30–45 minutes before engaging in sexual intimacy; taking the drug on an empty stomach or at least avoiding a heavy or high-fat meal before taking the drug (this is especially important when using sildenafil); and engaging in adequate genital stimulation before attempting intercourse. Drinking small amounts of alcohol (one to two drinks) should not compromise the effectiveness of erectile dysfunction medicines, but larger amounts of alcohol can diminish a man’s ability to have an erection.
×