FAQ Takeaway We did a deep dive into five over-the-counter alternatives to Viagra to determine whether they work and how to use them. Maskot/Getty Images Erectile dysfunction (ED) affects.Angina severe chest pain , unstable or Arrhythmia irregular heartbeat, within the last 6 months or Blood vessel problems eg, aortic stenosis, idiopathic subaortic stenosis or Heart attack within the last 6 months or Heart failure or Hypertension high blood pressure or Hypotension low blood pressure or Retinal disorders eye problem or Retinitis pigmentosa an inherited eye disorder or Stroke within the last 6 months —Should not be used in patients with these conditions. Its effects might last longer if you have mild to moderate ED. Different brands may not work the same way. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking sildenafil. If you have an erection that lasts more than 4 hours, get medical help right away.Key takeaways: Muse, Caverject, and Trimix can be good substitutes for Viagra (sildenafil). But they require insertion or injection into the penis. There’s some evidence that L-arginine might help with ED as an oral supplement. But it may not be safe for everyone. There’s not much evidence that trazodone, ginseng, or yohimbine help with .  · Viagra; Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where . In most males,* Viagra works within 1 hour after it’s taken. It’s possible that Viagra can begin working within 30 minutes of being taken. But other times, it may take up to 4 hours to start.Storage Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. These medicines are called PDE5 inhibitors. Some illegal “street” drugs called “poppers” such as amyl nitrate, butyl nitrate, or nitrite. Place the tip of the syringe into you or your child’s mouth and point it towards the cheek. A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow.