Hormone therapy means several hormones, each available in several forms. The differences between those forms are where most of the risk and most of the benefit actually live.
Reviewed by Allison Mollet, PA-C, MSCP
Updated August 2026
A bioidentical hormone has the same molecular structure as the one your body makes. Estradiol is the estrogen your ovaries produce, and estradiol prescribed as a patch is bioidentical. Micronized progesterone is identical to your own progesterone.
The word is often used as though it meant compounded. It does not. Several bioidentical hormones are FDA-approved, made by pharmaceutical manufacturers and covered by most insurance.
The contrast is with hormones that are not structurally identical to your own. Conjugated equine estrogen is derived from the urine of pregnant horses, and it is a mixture of estrogens, several of which the human body does not make. Synthetic progestins such as medroxyprogesterone acetate are a different molecule again.
Those two are what the Women's Health Initiative tested. Neither is what we prescribe.
So "bioidentical" describes the molecule. "Compounded" describes who prepared it. Two separate questions, and both come up when a plan is built.
Estrogen treats hot flashes and night sweats, and much of the sleep, mood and joint symptoms of the transition. The form it arrives in changes how it behaves.
Estrogen swallowed as a pill passes through the liver first. That first pass raises the production of several clotting proteins, and it can raise triglycerides.
Estrogen delivered any other way largely bypasses that first pass. Through the skin, through vaginal tissue, or by injection, it enters the bloodstream directly and does neither of those things to the same degree.
Patches are applied once or twice weekly and hold steady levels with nothing to remember daily. Gels and sprays go on daily and allow finer dose adjustment. Injections are another non-oral option and also avoid the liver.
Vaginal delivery can be either local or systemic, and this is less widely understood than it should be. At low dose, a ring or cream treats local tissue with little reaching the bloodstream. At a higher dose, a ring or a compounded estradiol cream delivers systemic levels — and because the route is vaginal, it bypasses the liver the same way a patch does.
Oral estrogen remains reasonable for some women, and is sometimes the practical choice on cost or preference.
Estrogen stimulates the uterine lining. Unopposed, that stimulation raises the risk of uterine cancer. Any woman with a uterus who takes estrogen also takes progesterone. A woman who has had a hysterectomy generally does not need it.
Which progesterone is a separate question, and it is one where we hold a position.
Micronized progesterone is bioidentical, FDA-approved, and usually taken as a capsule at night, which suits it well because it tends to improve sleep. Synthetic progestins are a different class of molecule with similar effects on the uterine lining and different effects elsewhere.
Observational studies suggest the type of progestogen may influence breast cancer risk. Micronized progesterone has generally been associated with little or no increase. Certain synthetic progestins have been linked to higher risk, similar to what the WHI reported.
No randomized trial has compared them directly, so this is a reasoned position rather than a settled one. We use micronized progesterone. Our what the WHI actually showed page sets out the evidence.
Progesterone also has a role of its own in perimenopause, where it is the hormone that falls first. That is covered on our perimenopause page.
Vaginal dryness, discomfort with sex, urinary urgency and recurrent urinary infections are caused by low estrogen in the local tissue, and they respond to estrogen applied there.
It comes as a cream, a tablet or insert, or a low-dose ring. All three work, and the choice is mostly preference and convenience.
Very little reaches the bloodstream, so its risk profile is far lower than systemic therapy. It can be used alone or alongside systemic hormones, and many women who do not need or want systemic treatment do well on this by itself.
It is also worth starting before symptoms are established. The thinning of vaginal and urinary tissue after menopause progresses rather than resolving, and treating it early prevents rather than repairs.
Testosterone is a hormone women produce and lose with age, and it declines gradually from a woman's twenties rather than falling at menopause.
The clearest documented effect is on sexual desire. Women also report better energy, steadier mood and strength that responds to training, and that is what we see.
There is no FDA-approved testosterone product for women in the United States, so it is prescribed off-label at female-appropriate doses and monitored with labs. Usually a daily cream or gel, or a low-dose injection. Our *testosterone for women* page covers it in full.
Two things guide the choice.
The first is clinical: which hormones you need, at what dose, and by which route. That is where the oral-versus-transdermal difference and the choice of progesterone do their work.
The second is how easily the plan can be changed once it is running, and this matters more than it sounds like it should.
Absorption varies between women, considerably with transdermal forms. Symptoms respond at different rates. The dose that is right in month one is frequently not the dose that is right in month four.
So we work with forms that can be adjusted — patches, gels, creams, capsules and low-dose injections, where a dose can be raised, lowered or stopped as your response tells us what is needed.
Pellets are implanted and release hormone over three to four months from a dose set at the moment of insertion.
That dose cannot be trimmed. The level travels a wide arc over the interval, and once a pellet is in it is not practically removable. If the dose turns out to be wrong, the choice is to wait it out or to cut it out.
Everything that makes hormone therapy work well is in the adjusting. That is the whole of our objection, and it is why we use forms that allow it.
The choice between forms is a clinical decision, not a product preference. Non-oral estrogen because the mechanism is better. Micronized progesterone because it is the molecule the body makes and the observational data favor it. Vaginal estrogen wherever the symptoms are local. Approved or compounded follows from what the woman needs.
— Allison Mollet, PA-C, MSCP
FDA-approved products are manufactured to a standardized dose, tested for consistency, and usually covered by insurance and filled at your own pharmacy for a copay. Where an approved product fits the plan, it is often the practical choice.
Compounded preparations are made by a compounding pharmacy to a prescription. They allow doses and combinations that are not commercially available.
That matters when a woman needs something between standard strengths, cannot tolerate an ingredient in a manufactured product, or needs a hormone with no approved female product. Testosterone is the clearest example.
It also allows a compounded estradiol cream at a dose that gives systemic levels vaginally, which is not something the manufactured products offer.
We are not committed to either category. The plan uses whichever suits the hormone, the dose, and the woman.
It starts with a full picture. Comprehensive labs — hormones, thyroid, metabolic markers, nutrients, organ health — read against your symptoms and your history.
Symptoms overlap heavily between hormonal and non-hormonal causes, and thyroid disease is missed often enough to be worth excluding at the start.
Then the hormones, in the forms that fit. Estrogen if indicated, usually non-oral. Micronized progesterone alongside it if you have a uterus. Vaginal estrogen where symptoms are local. Testosterone where it belongs.
Then adjustment, over months. This is the part that is consistently underestimated.
A dose that is correct on paper may not be correct for you. Absorption varies between women, considerably with transdermal forms.
Symptoms also respond at different rates. Hot flashes and sleep often improve within weeks. Mood, energy and body composition take longer.
And how you feel is the measure that matters, which means each change needs time to show its effect before the next one is made.
Labs guide the process rather than setting the target. We are treating your symptoms and your biology, and the numbers inform how.
The first prescription is a starting point. Expect the months after it to involve real adjustment, and expect the follow-up that goes with that.
The most common reason hormone therapy disappoints is that it was started and never adjusted. A woman is given a standard dose, feels somewhat better, and concludes hormones do not work for her. Almost always the plan simply never finished. Getting it right takes months of deliberate adjustment against how she feels.
— Allison Mollet, PA-C, MSCP
Let's begin
Your evaluation covers comprehensive labs and an unhurried hour with a Menopause Society Certified Practitioner, then a plan using the hormones and forms that suit you. To speak with us first, call 714-671-2005.
The benefits of hormone therapy
What the Women's Health Initiative actually showed
Testosterone for women
Perimenopause: what's happening, and what helps
That the hormone is structurally identical to the one your body produces. Estradiol and micronized progesterone are both bioidentical, and both are available as FDA-approved products. It is not a synonym for compounded — it describes the molecule, not who prepared it.
For most women, yes. Estrogen taken by mouth passes through the liver first, which raises clotting proteins and can raise triglycerides. Any other route largely avoids both — skin, vaginal or injection — which is why non-oral forms are generally preferred here.
If you have a uterus and you are taking estrogen, yes. Estrogen without progesterone increases the risk of uterine cancer. If you have had a hysterectomy, generally not.
Micronized progesterone is bioidentical, the same molecule your body makes. Progestins are synthetic molecules with similar effects on the uterine lining and different effects elsewhere. Medroxyprogesterone acetate, used in the WHI, is the best known.
Observational data suggest the choice may matter for breast cancer risk, with micronized progesterone generally associated with little or no increase. No randomized trial has compared them directly. We use micronized progesterone.
Neither is better as a category. Approved products are standardized and usually covered by insurance. Compounded preparations allow doses and combinations that are not commercially available, which is sometimes exactly what is needed.
No. A pellet delivers a fixed dose for three to four months, the level travels a wide arc over that time, and it is not practically removable once inserted. Adjusting the dose is most of what makes hormone therapy work, and a pellet removes the ability to do it.
FDA-approved prescriptions are filled at your own pharmacy and usually run through insurance as a copay. Compounded prescriptions are handled differently. The specifics are on our Bioidentical Hormone Therapy page.
Hot flashes and sleep often improve within a few weeks. Mood, energy and body composition generally take longer. Reaching a settled plan usually takes several months of adjustment, because absorption and response vary between women and each change needs time to show its effect.
Yes. They do different jobs. Vaginal estrogen treats local tissue with minimal systemic absorption; systemic therapy treats hot flashes, sleep and bone. Many women use both.
