Intraurethral agents, sometimes called transurethral agents, are medications that treat ED by increasing blood flow to the penis to achieve and maintain erection. Medicated urethral suppository for erection (MUSE®) is the only intraurethral agent approved by the U.S. Food and Drug Administration (FDA). You insert this suppository directly into the head of your penis while standing, directly after urination. The timing is important as it helps to lubricate the suppository and aid its insertion. The tissue inside your penis absorbs the suppository. You should massage gently while holding your penis upright to help absorption and avoid leaking. Then, sit, stand, or walk for up to 10 minutes while the tissue absorbs the medication and your penis is erect.
The medication works by softening the surrounding tissue and making your blood vessels expand, which increases the blood flow. The increase in flow causes an erection. Erections should come within 5 to 10 minutes of using MUSE®, and you should have sexual intercourse within 10 to 30 minutes after the medicine takes effect. Erections that last after ejaculation are not uncommon, but should be gone within an hour. Consult your physician if your erection lasts longer. If your sex partner is pregnant, always use a condom to protect the fetus from exposure to any of this medicine, although the chances of actually harming the fetus are rather low. The medication works for about 35 percent of men.