Body-identical HRT explained: estradiol and progesterone

Modern HRT is mostly built from two hormones: an oestrogen called estradiol and, for women who have a womb, progesterone. When these are described as body-identical, it means they are molecularly the same as the hormones your own ovaries used to make. This article explains what that means for how HRT is given and why.

Treatment is always individualised, and the right approach depends on your history. This is the general picture, not a prescription.

What body-identical means

Body-identical hormones are manufactured to be structurally identical to your own estradiol and progesterone. They are regulated, licensed products available on prescription. They are not the same as compounded bioidentical hormones, which are custom-mixed in unregulated quantities and are not recommended, because their dosing and quality are not assured. When clinicians say body-identical, they mean the licensed, regulated versions, which are the standard of care.

The oestrogen: estradiol through the skin

Estradiol is the part of HRT that treats most symptoms: the flushes, sweats, sleep disruption and mood changes. It can be given as a gel, a patch or a spray applied to the skin, or as a tablet. The skin routes are generally preferred. Going through the skin avoids the first pass through the liver that a tablet takes, and that matters because it means transdermal oestrogen does not carry the increased risk of blood clots that oral oestrogen does. For women with extra clot risk factors, including migraine or a higher body weight, the skin route is the safer default.

The progesterone: protecting the womb lining

If you have a womb, oestrogen on its own would thicken the womb lining over time and raise the risk of cancer of the lining. Progesterone is added to protect it, which is not optional but essential. The body-identical form is micronised progesterone, usually taken as a capsule at night; many women find it helps their sleep. Women who have had a hysterectomy and no longer have a womb generally take oestrogen alone, with no need for progesterone.

Cyclical or continuous

How the progesterone is taken depends broadly on where you are in the transition. Women who are still having periods usually take it in a monthly pattern, which produces a regular bleed. Women whose periods have stopped usually take both hormones every day, with the aim of no bleeding at all. The exact regimen is a clinical decision made with you, and it can be adjusted. The principle to take away is simply that the womb lining is always protected.

Finding the right dose

The first prescription is a sensible starting point, not a final answer. Most women notice flushes and sweats easing within a few weeks, while sleep, mood and energy take longer, often a couple of months. The dose is then titrated to your symptoms and how well you tolerate it, which is why a review at around three months matters. Using a symptom score at each review makes it clear whether a dose needs nudging up or holding steady.

Choosing a form that fits your life

Estradiol through the skin comes in several forms, and the choice is partly practical. A patch is changed once or twice a week and is easy to forget about, which suits people who would rather not think about it daily. A gel or spray is applied each day and lets the dose be fine-tuned in small steps, which can help when titrating. Some women find a patch irritates the skin in warm weather, while others dislike waiting for a gel to dry. None is clinically better than the others for most people; the best form is the one you will use reliably.

Micronised progesterone is usually a capsule taken at night. If it makes you too drowsy or does not suit you, there are alternatives, including a hormone-releasing coil that delivers progestogen locally and doubles as contraception. These are the kinds of practical adjustments a review is for.

What HRT is and is not

HRT is the most effective treatment for menopausal symptoms, and for women who start within ten years of menopause it also supports bone strength. It is not a longevity drug or a guaranteed shield against disease, and it should not be sold as one. It treats symptoms, and it does so well. Whether it is right for you depends on your symptoms and your history, which is what an assessment is for.

Ready to start?

If you want to move from reading to acting, the next step is a short assessment with a doctor on the GMC GP Register. It takes about ten minutes and tells you whether HRT is right for you.

Begin your assessment at this link. Online or in person at Westfield London.