Male Contraceptive Research Continues at UCLA

Kiyoshi Tomono

(U-WIRE) LOS ANGELES -- Forgetting a condom may no longer be an excuse for men if researchers at Harbor-University of California-Los Angeles Medical Center are successful.

As physicians in the center's department of endocrinology, metabolism, and nutrition, Dr. Ronald Swerdloff and Dr. Christina Wang, have spent the past few years developing a hormonal contraceptive for males. The contraceptive would be a third alternative -- other than condoms and vasectomies -- for men who want to prevent impregnating a woman.

Now, the physicians said, they are closer than ever to reaching that goal.

"Studies ... have shown that the hormonal male contraceptive can be as effective as the available oral birth control pill for women in preventing pregnancy," Swerdloff said. "In the past, these studies have used injectable testosterone as the form of male contraception."

The fruit of the researchers' most recent labor is a series of implanted rods, modeled after a similar device for women called Norplant. Norplant is placed beneath the skin of the upper arm and emits a continuous stream of the female hormone progestin.

Unlike earlier studies where testosterone was injected into muscles, Swerdloff and Wang recently implanted the rods along with testosterone pellets to produce a sustained source of female and male hormones.

According to Wang, they are still trying to clear up the right dosage and type of hormones, so that the agents are administered anywhere from six months to a year.

"Recently there have been studies done at a number of research institutions that have indicated that a combination of testosterone, the male hormone, and progestin ... are more effective than testosterone alone in suppressing sperm counts," Swerdloff said.

The doctors said there are two running explanations as to why the combination is more effective than using testosterone alone.

First, Swerdloff said, the combination may be more effective in turning off the signal from the pituitary gland that stimulates the testes to produce sperm. Second, the female hormone progestin may act directly on the testes to decrease sperm counts.

The researchers plan on testing out their theories on progestin in June, when they will begin a new study by recruiting 40 subjects to test their hormone cocktail's effectiveness.

If the mix is effective and they are able to secure a pharmaceutical company to fund a larger-scale study, Swerdloff said it could take up to five to seven years before a product actually hits shelves.

"In all of the studies we've done and have been done by other investigators, all have shown that this hormones approach is entirely reversible," Wang said. "The effectiveness also seems to be clear, but we are fine-tuning the agents for ... timing of administration."

Doctors use a small surgical procedure to insert the tubes under the skin of the upper arm under local anesthesia, Swerdloff said. A less painful version of the hormone combination could employ a hormone-impregnated patch, Wang said, which would deliver the drugs through the skin.

Even if approved as safe and made into a product, first-year computer science engineering student Manning Yuan said he'd be reluctant to use the implants.

"It's just the fact that you can't control it once it's in," Yuan said. "Surface contraception (condoms) is just more convenient."

Cecilia Mak, a fourth-year communications studies student, disagreed, saying that contraception also involves responsibility.

"I would use it (in a relationship) because it's wrong that women have to hold the weight and burden of contraception," Mak said.