2. Penile suppositories or injections

These produce erections by injecting or inserting into the penis a drug that increases blood flow. Urethral suppositories, the size of a grain of rice, are inserted via the head of the penis; injections are self-administered near the base of the penis.

The actual insertion of the suppository into the penis isn’t painful, say experts. Nor is the injection itself — done with a very small, thin needle. “Both [methods] are around a 1.5 to 2 on a zero-to-10 pain scale,” Kohler says, “where zero is no pain and 10 is getting run over by a truck.”

The biggest complaint about these treatments is a burning sensation in the penis as the drug takes effect. The frequency, intensity and duration of that side effect vary by method and user but can, in some cases, be bad enough, Montague says, that “a man will get an erection but be too uncomfortable to use it.”

Suppositories “were developed so men wouldn’t have to use needles,” Bivalacqua says. They contain the drug alprostadil (also known as prostaglandin E1) and are sold under the brand name Muse. If they are going to work, it takes about five to 10 minutes. However, Muse produces erections in only 30 to 40 percent of patients, usually those with mild ED, because some of the drug is absorbed systemically and diverted from its function of opening penile arteries to allow more blood to flow in. The out-of-pocket cost is around $20 to $30 per suppository.

For men who don’t mind needles, injections come in various formulations: alprostadil alone; a two-drug combo called bi-mix, which can either be alprostadil mixed with phentolamine or phentolamine mixed with papaverine; and tri-mix, a three-drug mixture of phentolamine, papaverine and a low dose of alprostadil. 

Of these formulations, alprostadil alone carries the highest reported rate (50 percent of users) of burning and pain; in bi-mix users the rate of burning is around 10 percent, and in tri-mix users it drops to less than 3 percent of users, says Nehra. “And that improves dramatically over time as men get used to the injection,” he adds.

Because the burning side effect is triggered by alprostadil, the formulations with the least alprostadil — tri-mix and certain versions of bi-mix — could work for men who experience burning with the single-drug formula. But some men might choose alprostadil alone because the multi-drug cocktails can cost more and must be dispensed by a compounding pharmacy — one that is authorized to mix medications on site — which could mean the added hassle of a long drive to pick up the drug.

Some injectable formulations need to be refrigerated — yet another reason many men steer away from the needle option. Among ED treatments, injections are also the most common cause of extended erections — rigidity lasting more than four hours, also called priapism — which afflict about 3 to 7 percent of users, Kohler says. That condition, while easily treated with an adrenaline shot, requires urgent attention at a clinic or hospital. The cost of this ED treatment is $2 to $5 per injection.

Next: No. 3: Surgically implanted prostheses. »