Types of progesterone in HRT

A progestogen is any hormone that does the job of progesterone in the body. In HRT it comes in a few different forms.

Micronised progesterone

The NHS website describes it as progesterone identical to the hormone your ovaries make. It is the body-identical option, and the NHS website says it comes as capsules. The Pakistan Menopause Society lists micronised progesterone among the regulated, licensed body-identical hormones it recommends (5.10).

The European Menopause and Andropause Society (EMAS) says micronised progesterone by mouth may help sleep more than other progestogens, and The Menopause Society, in the US, notes that it can make you drowsy.

Synthetic progestogens

Made to act like progesterone without being identical to it. The British Menopause Society's guide names dydrogesterone, norethisterone, medroxyprogesterone acetate, levonorgestrel and others. Some come as tablets, some are built into a combined tablet or patch with the estrogen.

The hormonal coil

A small device placed in the womb that releases levonorgestrel, a progestogen. In Urdu it is hormone wali coil. The PMS recommendations note that the same coil also works as contraception (5.12).

Estrogen on its own can make the womb lining grow. The NHS website explains that estrogen-based HRT can thicken the lining, which slightly raises the risk of womb cancer, and that taking progesterone alongside it reduces that risk. The Pakistan Menopause Society says the same: a progestogen is added for women who have not had a hysterectomy (5.4).

How it is taken depends on where you are in the transition. The PMS recommendations describe sequential regimens, with a progestogen for part of each month and usually a monthly bleed, and continuous combined regimens, with both hormones every day and no planned bleed (Table 8). The BMS guide says sequential is usual while periods are still coming, and that a switch to continuous can be tried later.

NICE NG23 recommends that a woman who wishes to take HRT and still has her womb is offered combined HRT, and one who has had a total hysterectomy is offered estrogen-only (1.8.1).

On which progestogen, this is what the guidance says:

• The BMS guide reports that micronised progesterone and medroxyprogesterone acetate were equivalent at protecting the lining in the trials it reviewed.
• The BMS says the levonorgestrel coil protects the lining within HRT for up to five years. The PMS recommendations call it effective protection plus contraception, with fewer side effects, and say it should not be used by women who have had breast cancer (5.12). On breast cancer risk, the British Menopause Society and Women's Health Concern report early data showing a risk similar to HRT with progestogen tablets, and call the coil's effect unclear. The International Menopause Society does not recommend it for women at high risk of breast cancer. How that weighs for you is a question for your doctor.
• The BMS says progesterone creams and gels through the skin are unlikely to protect the lining enough, and does not recommend compounded bioidentical products.

The PMS recommendations also describe a pairing of estrogen with bazedoxifene for women who cannot tolerate a progestogen, which protects the lining without one (5.8). Which of these fits you is your prescriber's call, made with your history in front of them.

Some irregular bleeding is common in the first months of HRT. NICE NG23 says it is common during the first six months, and advises seeking medical help promptly for unscheduled bleeding after that (1.8.4). The BMS guide adds that bleeding still going on after four to six months, despite changes to the progestogen, should be checked.

Bleeding after your periods have stopped, when you are not on HRT, needs checking too: the PMS recommendations list it among the red flags (2.3). See bleeding after menopause.

The coil sits where menopause meets family planning, and that can make it a conversation for two. The PMS recommendations note that women still need contraception for a time after their last period (5.13), which is one reason a doctor may suggest the coil. What a couple decides about family planning is theirs. Any question of religious permissibility belongs with a qualified scholar.