Bioidentical hormone therapy: what it is and who it suits
What bioidentical hormone therapy is, how it differs from the older synthetic hormones, what it helps with in the menopause and who it is not suitable for.
The menopause is an entirely natural, expected stage of a woman's life — like puberty or pregnancy. But as the ovaries slow down and oestrogen and progesterone fall, complaints can follow that affect daily life: hot flushes, sleep problems, joint pain, vaginal dryness and "brain fog". Medicine today offers a modern approach to making this transition more comfortable, known as bioidentical hormone therapy.
So what exactly is it, what does it do, and how does it differ from the older treatments?
What does "bioidentical" mean?
The term means that the hormones used — oestrogen or progesterone — are chemically and molecularly identical to the ones a woman's own ovaries produce. They are generally derived from plant sources (certain types of sweet potato, or soya) and converted in the laboratory into an exact copy of the human hormone. The body does not read them as a foreign substance taken from outside, but as a natural part of its own production, and they fit the receptors on the cells like a key in a lock.
An important caution: the treatment described here means regulated medicines, approved by the Ministry of Health and international authorities and sold in pharmacies. Uncontrolled mixtures made outside proper manufacturing or compounded individually in a pharmacy should be avoided; the reliability, purity and effectiveness of those unregulated preparations have not been demonstrated.
How does it differ from synthetic hormones?
The reports that spread in earlier years — particularly in the early 2000s — about hormone therapy being risky came down to the type of hormone used at the time and the way it was given. Those studies used "synthetic" oestrogens structurally different from the human hormone (derived from horse urine, for instance) and synthetic progestins, taken by mouth as tablets.
The main differences are these:
- Clotting risk: the older synthetic oestrogen tablets could affect clotting factors as they passed through the liver. The bioidentical oestrogens used today are generally applied through the skin — as a gel, spray or patch — so they do not burden the liver and do not increase the risk of venous thromboembolism.
- Effect on breast tissue: the synthetic progestins used in the older treatments were seen to cause certain side effects with long-term use. Natural micronised progesterone, the bioidentical form, has a safer profile for breast tissue than the synthetic versions and does not affect metabolism adversely.
What are the benefits?
Started under specialist supervision, at the right dose and at the right time — particularly during the menopausal transition or within the first 10 years of the menopause — the main benefits are:
- brings hot flushes and night sweats largely under control;
- improves sleep quality and reduces daytime tiredness;
- relieves vaginal dryness, burning and pain during intercourse caused by oestrogen deficiency;
- slows bone loss (osteoporosis) and markedly reduces the risk of fracture in later years;
- supports heart and vascular health, with a protective effect when started early.
Who is it not suitable for, and what are the risks?
As with any medical treatment, bioidentical hormone therapy has to be assessed individually. It is not a single prescription that fits everyone. Hormone therapy is generally not considered suitable for women with an active or past hormone-sensitive cancer (breast cancer, for example), vaginal bleeding of unknown cause, active liver disease, or a recent heart attack. During treatment it is very important for safety to keep to the check-ups your doctor recommends and to have annual mammography and smear (cervical screening) tests.
You do not have to spend this new stage of life struggling. Do speak to your own doctor about understanding the changes in your body and planning the medical support that suits you.
This page is for information. It does not replace an examination or individual medical advice.