In short
The word bioidentical is used for two very different things, and only one of them is prescribed here.
- Regulated bioidentical hormones are licensed products with the same molecular structure as your own hormones. 17-beta oestradiol and micronised progesterone are both bioidentical, and both are standard first choice treatment.
- Compounded bioidentical hormones are custom mixed in a pharmacy, with doses steered by repeated saliva or blood testing. These are not prescribed.
The reason is quality control. When compounded products were tested, their strength ranged from 67.5 to 268 per cent of what the label claimed.
Treatment Overview
What does bioidentical actually mean?
Technically, a bioidentical hormone has the same molecular structure as a hormone your own body makes. 17-beta oestradiol is bioidentical. So is micronised progesterone.
Both are available as licensed, regulated products, and both are what most specialists reach for first. If that is what you mean by bioidentical, it is already the standard of care.
So what is the argument about?
In everyday use, bioidentical has come to mean something else: a custom compounded mixture of several hormones, made up by a pharmacy, with the dose adjusted from repeated hormone testing.
The hormones usually mixed in are oestradiol, oestrone, oestriol, progesterone, testosterone and DHEA. That is the version that expert bodies advise against.
What is the difference in practice?
| Regulated | Compounded | |
| Same structure as your own hormone | Yes | Yes |
| Dose checked by a regulator | Yes | No |
| Purity and sterility overseen | Yes | No |
| Trial evidence for safety and effect | Yes | None |
| Comes with a package insert and warnings | Yes | Not required |
Is natural the same as safer?
No, and the marketing here is genuinely misleading. Almost all oestrogens used in hormone therapy, licensed ones included, start from plant material.
17-beta oestradiol is made from diosgenin, a compound in Mexican yam. It is extracted and converted in a laboratory. The licensed product and the compounded one go through the same chemistry. Only one of them is then checked.
Which bodies advise against compounded hormones?
The Menopause Society, the American College of Obstetricians and Gynecologists and the Endocrine Society all advise against custom compounded hormone therapy. Their reasoning is consistent:
- Licensed products already exist in every category, so there is no gap to fill
- No randomised trial has shown compounded hormones to be either effective or safe
- Content, dose, quality and sterility are not subject to regulatory oversight
- They do not have to carry the warnings that every licensed oestrogen carries
Is there a real world consequence?
Possibly. Endometrial cancer rates in women aged 50 to 74 were stable between 1992 and 2002. After 2002 they rose by about 2.5 per cent a year, with a 10 per cent rise between 2006 and 2012.
Over the same period compounded use rose while licensed combined products fell. That is an association, not proof, but it is the kind of signal that regulation exists to catch.
What is prescribed instead?
A bioidentical regimen using licensed products, which for most women means:
- 17-beta oestradiol through the skin, as a patch or gel, which avoids the liver first pass and carries a lower clot and stroke risk than tablets
- Micronised progesterone, 200 mg for 12 days a month or 100 mg daily, taken at bedtime
- Or a single licensed capsule combining 1 mg oestradiol with 100 mg progesterone, both bioidentical, if you prefer one tablet
Who Is a Good Candidate?
- You want bioidentical hormones and want to understand what is actually in them
- You are currently on a compounded mixture and want to move to a regulated equivalent
- You have been told licensed hormone therapy is synthetic and want that claim checked
- You have menopausal symptoms and are under 60 or within 10 years of your last period
- You are looking for a clinic that will adjust doses from repeated saliva hormone testing, which is not done here
- A history of breast cancer, coronary heart disease, stroke or a previous blood clot
- Active liver disease or unexplained vaginal bleeding
What Happens During the Consultation
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1
What you are taking now
If you are on a compounded product, we go through what is in it, at what stated dose, and what has been monitored so far.
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2
Symptoms and risk
Which symptoms you actually want treated, and your cardiovascular and breast cancer risk, which decide the route and dose.
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3
Matching to a licensed equivalent
Every hormone in a typical compounded mixture has a regulated counterpart. We map yours across, usually to transdermal oestradiol plus micronised progesterone.
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4
Review at three to four weeks
Symptom relief is checked in this window, and the dose is adjusted from how you feel rather than from a hormone level.
Program Structure & Follow-Up
How is a switch from compounded to regulated handled?
Usually directly, without a washout. The aim is to match the oestrogen effect you are already getting and to make sure the womb lining is properly protected.
What gets checked
| At the switch | Endometrial protection, route, dose equivalence |
| 3 to 4 weeks | Symptom control, side effects |
| 6 months | Bleeding pattern. Bleeding that persists beyond this on a continuous regimen needs a biopsy |
| Yearly | Dose, route, breast screening, and whether the balance still favours treatment |
Why is endometrial protection the first thing checked?
Because it is where compounded regimens most often fall short. Hyperplasia can develop after as little as six months of oestrogen without adequate progesterone.
If you still have a uterus, a progestogen is not optional. The form is negotiable, the protection is not.
Are hormone levels used to steer the dose?
Rarely, and never as the main guide. The dose is set by symptoms. Levels are measured only where they genuinely help, for example when adjusting between gel and spray preparations whose strengths are not directly comparable.
Benefits, Limits & Safety
Do regulated bioidentical hormones work as well?
Better, in the sense that they are the products the evidence was built on. Standard doses clear hot flushes completely in about 80 per cent of women and reduce them in the rest.
Across 24 trials in 3329 women, oestrogen reduced flushes by about 75 per cent compared with placebo. None of that evidence comes from compounded products.
What are the limits?
Bioidentical does not mean risk free. The same cautions apply as to any systemic hormone therapy, and the same contraindications.
It is also not an anti ageing treatment. Hormone therapy is no longer recommended for preventing heart disease, dementia or osteoporosis, though bone benefit does come along with symptom treatment.
What are the actual numbers?
For 1000 women starting between 50 and 59 and treated for five years with combined therapy: about three extra breast cancers, three extra pulmonary embolisms, one and a half fewer hip fractures and five fewer deaths from any cause.
Micronised progesterone is preferred over the older synthetic medroxyprogesterone, which was linked to excess breast cancer and heart risk in the WHI. This is one place where bioidentical genuinely does appear to matter.
What about testosterone and DHEA in the mix?
Routine testosterone is not recommended for postmenopausal women. It helps sexual desire in carefully selected cases, mostly after both ovaries have been removed, but has no proven benefit for bone, mood, memory or hot flushes.
Adding it to a general hormone mixture, as compounded regimens often do, has no evidence behind it.
What you get
The same bioidentical molecules, at a dose you can rely on, backed by the trials the treatment guidelines are actually built on.
What is watched
Endometrial protection, bleeding pattern, breast screening, and a yearly review of dose, route and duration.
What is not offered
Custom compounded multi hormone mixtures, saliva hormone monitoring, and routine testosterone or DHEA added without an indication.
Cost & Program Investment
The consultation is quoted individually and includes the review of anything you are already taking, the risk assessment and the prescription plan. Licensed hormone products are ordinary prescription medicines and are bought from a pharmacy at pharmacy prices, which is usually less than a compounded equivalent. There is no package to buy into and no minimum commitment.
Frequently Asked Questions
No. Bioidentical oestradiol and micronised progesterone are first choice treatment and are prescribed here. The problem is with custom compounded mixtures, not with the molecules.
Because you cannot know what dose you have been taking. When compounded products were tested, potency ranged from 67.5 to 268 per cent of the label. A regulated equivalent gives you the same effect at a dose you can rely on.
Almost all of it, licensed or compounded, is made from plant precursors converted in a laboratory. The only common exception is conjugated equine oestrogen, which comes from horse urine and is not what is prescribed here.
It is not used to steer treatment. Doses are set from symptoms. Saliva levels do not predict how well symptoms are controlled.
Not from this clinic. Every hormone that appears in a typical compounded mixture has a regulated equivalent, and that is what will be offered instead.
Yes. A licensed capsule combines 1 mg 17-beta oestradiol with 100 mg micronised progesterone. Both are bioidentical, it protects the womb lining, and in a one year trial it had no meaningful effect on weight or blood pressure.
Through the skin, for most women. Transdermal oestradiol avoids the liver first pass, so it carries a lower risk of clot and stroke, and showed no excess clot risk even in women with a clotting mutation or a high BMI.
Evidence
Where this information comes from
Every figure on this page is taken from the sources below. All of them are free to read, so you can check them yourself.
This page is general medical information and does not replace a personal consultation. Trial results are averages across large groups, not a prediction for any one person.