What Is Bioidentical or Body-Identical Hormone Therapy?

Bioidentical hormones

Bioidentical or body-identical hormones are estradiol and progesterone that are molecularly identical to human hormones. Most (not all) modern menopause hormone therapy is bioidentical. Keep reading for a list of brands.

The difference between “bioidentical” and “body-identical” is that body-identical is the preferred conventional term and bioidentical is the term traditionally applied to customised hormone formulas dispensed by a compounding pharmacist back when compounding was the only way to obtain such hormones.

Today, bioidentical products are available from any doctor and pharmacy and are widely
regarded as safer than non-bioidentical hormone therapy.

Bioidentical hormone therapy is safer

Bioidentical hormones have fewer side effects than contraceptive drugs or older types of hormone therapy such as conjugated horse estrogens (Premarin®), which were popular in the 1990s.

Did you know? Premarin is an old-style estrogen drug that contains about 30 different hormones, including androgens, many of which are not body-identical. The two main active ingredients are estrone sulfate and equilin sulfate, the second found only in horses. Together, the whole compound is referred to as conjugated equine estrogens and is extracted from pregnant mares’ urine.

Modern estrogen therapy is usually bioidentical estradiol and transdermal (absorbed through the
skin) which allows it to directly enter the bloodstream and not form dangerous blood-clotting factors in the liver. The safest type of estrogen is, therefore, an estradiol patch (Estradot® or
Climara®), gel (Sandrena® or Estrogel®), or vaginal estrogen.

Bioidentical progesterone does not cause mood side effects like progestins. Nor does progesterone carry the heart disease or breast cancer risk of progestins. In fact, according to Professor Prior, progesterone may even help to reduce the risk of breast cancer

Bioidentical progesterone is available as oral micronized progesterone capsules (brands Prometrium® and Utrogestan®). All other brands of “progesterone” are actually progestins (not progesterone), and that includes the tablets Primolut® and Provera® and the patch Estalis®. 

Which hormone therapy products are bioidentical?

List of bioidentical versus non-bioidentical hormone therapy

AngeliqBioidentical estradiol + progestin drospirenone
Kliovance or KliogestBioidentical estradiol + progestin norethisterone
FemostonBioidentical estradiol + progestin dydrogesterone
EstalisBioidentical estradiol + progestin norethisterone
Climara Pro patchBioidentical estradiol + progestin levonorgestrel
Evorel Conti patchBioidentical estradiol + progestin norethisterone
Livial or XyvionTibolone
ProveraProgestin medroxyprogesterone acetate
PrimolutProgestin norethisterone
Mirena IUDProgestin levonorgestrel
Estrofem tabletBioidentical estradiol
Progynova tabletEstradiol valerate that converts to bioidentical estradiol
Trisequens tabletBioidentical estradiol + progestin norethisterone
Climara patchBioidentical estradiol
Estradot patchBioidentical estradiol
Estraderm patchBioidentical estradiol
Vivelle patchBioidentical estradiol
Estrogel gelBioidentical estradiol
Sandrena gelBioidentical estradiol
Lenzetto sprayBioidentical estradiol
Vagifem Bioidentical estradiol
OvestinBioidentical estriol
Prometrium capsuleBioidentical progesterone
Utrogestan capsuleBioidentical progesterone
Famenita capsuleBioidentical progesterone
Teva capsuleBioidentical progesterone
Endometrin Bioidentical progesterone (vaginal)
CrinoneBioidentical progesterone (vaginal)
Bijuva capsuleBioidentical estradiol + bioidentical progesterone
Adapted from my book Hormone Repair Manual.
Bioidentical or body-identical hormone therapy.
read the label

Estrogen versus progesterone therapy for menopause and perimenopause

Transdermal bioidentical estradiol can relieve the hot flashes and mood disturbance of the menopause transition. It’s safest when combined with bioidentical progesterone.

Under current guidelines, the only officially recognised use of oral micronised progesterone is as the progesterone part of hormone therapy – in other words, estrogen plus progesterone, and, even then, only if you have a uterus. As I discuss in Hormone Repair Manual, progesterone can also be used on its own (without estrogen) for perimenopausal symptoms such as night sweats, heart palpitations, sleep issues, migraines, mood problems, and heavy periods. Even without a uterus, progesterone is beneficial for mood and breasts.

👉🏽 Tip: Perimenopause or “second puberty” are the two to ten years before periods actually stop. Symptoms include heavy periods, insomnia, anxiety, and night sweats, and are the result of losing progesterone, not estrogen.

adapted from Prof Jerilynn Prior’s “Perimenopause lost—reframing the end of menstruation.”

Progesterone-alone has a few advantages over estrogen:

👉 Tip: There’s no progesterone in any type of hormonal birth control.

Progesterone can also make periods lighter and is a good alternative to progestin drugs such as the pill. Bioidentical progesterone capsules can even be used together with the hormone IUD.

For more information about the benefits of progesterone, read:

And the following articles by endocrinology professor Jerilynn Prior:

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