Because MHT is such a widely used and studied method of treatment, a number of different MHT compounds and delivery methods have developed over the years. You and your doctor can determine the form that's best for you, but here are some of the most popular options:

• Pills can offer estrogen or estrogen/progestin combinations that are taken continuously, cyclically, or in pulse patterns of, for example, three days on then three days off.

• Patches can deliver a steady dose of estrogen or estrogen/ progestin combinations every day of the month. You change patches every three to seven days, and you can wear them when swimming or showering.

• Flexible vaginal rings deliver estrogen in steady doses to women who suffer from vaginal dryness. Some forms are available that make estrogen replacement safe even for breast cancer patients, because the estrogen works locally (in the vagina), and is not absorbed into the bloodstream (which could increase the potential for the recurrence of the cancer).

• Creams and gels provide topical estrogen or progesterone doses to women who suffer from vaginal dryness. Both creams and gels are applied directly inside the vagina; some women rub vaginal progesterone gels and creams directly on the skin. Again, your health care provider can advise you on the proper dose and delivery mechanism for these (and all) forms of MHT.

Low-Dose MHT

The Food and Drug Administration (FDA) has approved new formulations of estrogen/progestin that are much lower than combinations used prior to the WHI study. These formulations seem to offer good protection from osteoporosis, when women also take vitamin D and calcium. It is unclear yet whether these lower doses have the same risks as higher doses for cardiovascular disease and other conditions.

Bioidentical Hormones

Bioidentical hormones have been highlighted in the popular media. With celebrities touting them as the “safe” alternatives to conventional conjugated hormones, and declaring them a virtual fountain of youth, many women are curious about them. Also called “natural hormones,” bioidentical hormones are formulated to be exactly the same chemical as that produced naturally by the ovaries. The ovaries produce three types of estrogen: estradiol, estrone, and estriol. These formulations can be duplicated from plant sources, creating a chemical twin to what your body produces. Estradiol is available in FDA-approved forms, such as tablets, skin patches, and vaginal forms. Estriol and estrone are available from compounding pharmacies. Bioidentical progesterone is also available as tablets and vaginal gel, and from compounding pharmacies.

Proponents of bioidenticals point out that compounding pharmacies can create individual formulations that will meet each woman's particular hormone needs according to her symptoms and risks. Critics of bioidenticals suggest that compounding pharmacies produce an uneven product that can vary from batch to batch, and that some of the inactive ingredients will differ and affect the action of the hormone. The FDA-approved versions can offer a more proven safety record but are not as individualized.

The most controversial assumption about bioidentical hormones is that they are safer than their synthetic counterparts are. This remains to be seen, since they have not yet been studied side by side with the synthetic versions, and therefore may have all the same risks as those discovered in the WHI study.