Women who rely on birth control pills containing a progestin-estrogen combination but who don't always remember to take them every day have a new contraceptive option. Approved by the U.S. Food and Drug Administration last October (2000), Lunelle is a highly effective injectable contraceptive containing a progestin (medroxyprogesterone acetate) and an estrogen (estradiol cypionate). This combination of hormones prevents ovulation while maintaining monthly periods.

The other injectable contraceptive currently available in the U.S.—Depo-Provera®—contains only medroxyprogesterone acetate and tends to suppress menstruation, often to the point of eliminating monthly periods altogether.

Trials show effectiveness, safety

Lunelle is administered once a month as an intramuscular injection, which reduces the chance of user error (no daily pill to remember, no daily pill to forget). Indeed, fewer than 1% of women who choose Lunelle will become pregnant in the first year of use, making Lunelle among the most effective forms of contraception available. By way of comparison, the one-year pregnancy rate for the male condom is 14%; the diaphragm, 20%; combination birth control pills, 5%; and tubal ligation (female sterilization), 0.5%.

Based on studies in more than 5,300 women around the world, Lunelle appears to be a safe contraceptive option for women who would be candidates for combination birth control pills. Women who cannot take combination oral contraceptives for medical reasons (excessive smoking, heart or circulatory problems, estrogen-dependent cancer, or other co-existing medical problems) should not use Lunelle.

The most common side effects reported with Lunelle are essentially the same as those associated with combination birth control pills. In a large, 60-week U.S. study comparing Lunelle with a combination oral contraceptive (Ortho-Novum® 7/7/7), the most common minor side effects leading women to stop using Lunelle were menstrual irregularities, weight gain, emotional lability (mood changes), acne, and breast tenderness.

Lunelle versus Depo-Provera

The other injectable contraceptive available to women in this country, Depo-Provera, is a longer-acting, progestin-only formulation given every three months. One big difference between the two methods is how quickly fertility is restored after discontinuing use. Women who discontinue Depo-Provera generally experience a return to ovulation within 4 to 13 months. After discontinuing Lunelle, ovulation usually returns within 2 to 4 months—an advantage for some women. More than 50% of women attempting to become pregnant after stopping Lunelle do so within 6 months. In addition, Depo-Provera usually causes menstrual changes such as irregular bleeding or amenorrhea (the absence of periods), whereas such changes are uncommon in women using Lunelle.

Is Lunelle right for you?

In terms of side effects and effectiveness, Lunelle's performance in clinical trials proved it to be safe and substantially more effective than combination oral contraceptives. However, in terms of how users tolerated side effects (i.e., how many women stayed on Lunelle), oral contraceptives appear to have the advantage.

In terms of convenience, it's a trade off. The Pill is self-administered—you take it yourself—but you have to remember to take it, every day. Research suggests that upwards of 60% of women do not take their pill every day. In one study, 19% of women reported missing one pill per menstrual cycle, and 10% said they missed at least two. This is why 5% of women using oral contraceptives in typical fashion become pregnant in the first year, compared with 0.5% or fewer of those who use them perfectly.

For now, using Lunelle requires a woman to go to a healthcare professional to receive her monthly injection. Nurses and other healthcare professionals employed in company health centers can give the injections, and in some states, pharmacists can give them as well. Pharmacia (the U.S. marketer of Lunelle) is working on development of a self-injected form of Lunelle, similar in concept to self-injected medications for diabetes or allergies, but that will probably be several years in the making.