Bioidentical hormones

Bioidentical means a hormone with the same chemical structure as one your body makes. Under that one word sit two very different things.

Licensed body-identical hormones

These are ordinary prescription HRT. The Pakistan Menopause Society calls them body-identical: pharmaceutical-grade, structurally identical to the body's own hormones, licensed and quality-controlled (section 5.10). Its examples are estradiol and micronised progesterone. Women's Health Concern says most traditional HRT used in the UK is already bioidentical, containing estradiol, the natural human estrogen, or micronised progesterone, so licensed estradiol gel and patches already count. The BMS describes micronised progesterone in the same way: plant-derived and similar in structure to the progesterone the ovaries produce.

Compounded bioidentical hormones

These are custom mixes made up to an individual recipe, often sold by a clinic or online as natural or tailored. The PMS recommendations call them unregulated, with variable dose and purity, and say the BMS, the International Menopause Society and the PMS do not recommend them because of the lack of regulation, evidence and safety data (section 5.11).

Some clinics set the custom dose from a saliva or urine hormone test. The Menopause Society, in the US, says those tests are unreliable and does not recommend them.

The BMS tells clinicians to make the distinction clearly. Regulated bioidentical hormones are prescribed medicines. Compounded ones are less tightly regulated, which raises concerns about purity and safety, and the BMS says they "should be avoided".

NICE NG23 makes the same point from the other side. Doctors are asked to explain that "the efficacy and safety of unregulated hormone preparations are unknown" (1.4.5), and that the safety, quality and purity of what is in unregulated preparations may be unknown (1.4.6).

On whether body-identical progesterone carries a lower breast cancer risk than other progestogens, the sources differ. The BMS says bioidentical hormones have a more neutral effect on clot and breast cancer risk than synthetic ones, and that micronised progesterone has "theoretically a slightly lower risk of breast cancer" than synthetic progestogens. NICE NG23 says there is not enough evidence to establish whether the increase in breast cancer risk with combined HRT differs with micronised progesterone or dydrogesterone compared with other progestogens. That is a conversation for your doctor, not a reason to go to a clinic.

NICE NG23 recommends offering HRT for hot flushes and night sweats (1.5.1), and the PMS recommendations call it the most effective first-line medicine for them in women who can take it (section 7.1.1). If body-identical is what you want, the BMS says to ask your doctor for regulated hormones on prescription.

In Pakistan, the estrogen part is straightforward: body-identical estradiol gel is on the PMS list. The progestogen part is less so, because the list has no standalone micronised progesterone. If you have a womb, your doctor will choose another way to protect its lining. See progesterone types.

If you are already using a hormone cream, capsule or "natural" product from a clinic, a beautician or a website, show it to your doctor. Bring the packet.

That includes wild yam creams sold as natural progesterone. The Menopause Society says the body cannot turn wild yam into progesterone, and that tested yam creams often held no yam at all, while many had hidden hormones added.

If you still have your womb, estrogen without enough progestogen raises the risk of womb cancer, which is why licensed HRT pairs them (PMS section 5.4). Unexpected vaginal bleeding while using any hormone product needs checking.

Women ask whether a hormone medicine is something their faith allows, and what it is made from. The NHS website says estradiol in most estrogen medicines comes from plants. Whether a particular medicine is permissible is a question for a qualified scholar; exactly what is in it is a question for the pharmacist.

Many families have a herbal or desi remedy to suggest first, out of love. The BMS notes that women from ethnic minority communities often try supplements and herbal products before they seek medical help. The PMS recommendations ask for caution with over-the-counter supplements, because the evidence on their safety and effectiveness is limited (section 6.5).