Bioidentical hormones

So what are bioidentical hormones? Hormones which have the same structure, and therefore the same effects in your body as the hormones produced by your body.
Often they are called natural hormones - I find this misleading. The hormones are derived from a plant component diosgenin, initially sourced from wild yam but now primarily from soy. This is easily converted in a laboratory into progesterone, and then into oestrogens and androgens (DHEA and testosterone).
However, your body can't convert diosgenin. Taken orally as wild yam there is a mild oestrogenic effect, but no progesterone effect.
   With the publication of Dr John Lee's book, What your doctor may not tell you about menopause, in 1996, there was a massive renewed interest in progesterone. This coincided with the ability to micronise progesterone - make the particles small enough to be absorbed in a cream, lozenze,pessary,suppository or capsule form.
Prior to this progesterone had to be given by oily injection, which was quite unpleasant/painful and required every day or second day.
Most people have heard of Dr Lee and Dr Wright in the USA, but the use of progesterone goes way back to the extraordinary Dr Katharina Dalton in the UK in 1948.
   Dr Dalton had observed women whose asthma, epilipsy and migraine were exacerbated premenstrually, and successfully treated them with progesterone. Dr Dalton coined the term PMS, and co-wrote the first paper on PMS in 1953. She expanded her treatment to other PMS symptoms and post-natal depression
Later Dr Dalton became an authority on PMS and criminal behaviour - helping set a precedent in Engllish Law for PMS as a cause of diminished responsibility in serious crimes including murder.

Progesterone differs from progestogens (synthetic progesterones) in many ways, the effects being at times opposite -
Progesterone promotes gestation - it is used fairly routinely as vaginal gel in IVF treatment and to prevent miscarriage and preterm births. They would never use a progestogen for this as they are not progestational and may be teratogenic.
Progesterone decreases thyroid binding globulin, which increases free thyroid hormones improving metabolism; binds to GABA receptors providing antidepressant and antianxiety effects: blocks aldosterone causing diuretic effect: decreases oestrogen receptor synthesis and oestrogen induced mitosis and promotes cell differentiation, resulting in reduced breast cancer risk.
Progestogens increase salt and water retention, may cause depression, hair loss and may increase breast cancer risk. They have adverse effects on lipids, increasing LDL and reducing HDL and may adversely affect bone density.

  The effect of bioidentical hormones is due both to the chemical structure and the method of  delivery.
Using any oestrogen orally as a tablet causes an increase in clotting proteins made by the liver, increasing the risk of blood clots and strokes. Despite all the focus on the risk of breast cancer (to be discussed later) the increased risk of  "vascular events" has been higher in all the studies. The increase in clotting factors is mirrored by the increase in SHGB, but related to the decrease in activated protein C levels. This is especially important where there is a family history of clotting disorders.
When the oral contraceptive pill was being trialled in the early 1960's, hundreds of young healthy women in their 20's suffered strokes as a result of the very high oestrogen doses. This was largely covered up.
Using transdermal oestrogen (cream or patches) has been shown to have no adverse impact on risk of blood clots and strokes. This was confirmed by a large French study published in 2006 (The ESTHER study).They concluded that transdermal oestrogen and micronised progesterone was the safest therapy in regard to VTE (venous thromboembolism = blood clots) risk.
While using oestrogen after menopause has beneficial effects on cholesterol and vascular disease in women commencing treatment before age 60, this is negated by the effects of synthetic progestagens, but maintained by progesterone.
  Troches, or lozengers fall in between, as some is swallowed rather than directly absorbed in the mouth, however this is generally less than 20% of the effect from oral administration.
Troches are useful in early menopause where higher doses may be required. As there needs to be 100 times as much progesterone as oestrogen ( as oestradiol), and there is only so much that can be mixed into a cream, a troches allows for larger doses.
  The amount of progesterone in creams is usually adequate to maintain bone density, however to increase bone density I find troches are necessary to provide the required dose. While oestrogen slows breakdown of bone, progesterone and testosterone increase bone density by stimulating osteoblast activity.

  Triest/Biest or something else?
Triest is a combination of oestrogens containing 10% oestradiol, 10% oestrone and 80% oestriol. This was proposed by Dr Jonathan Wright as approximating the usual amounts in premenopausal women. This has been found not to be quite correct.
As oestrone is the least desirable oestrogen, because it binds mainly to the oestrogen alpha receptor which causes breast cell proliferation, and most women still produce significant amounts from adrenal androgens, I don't use oestrone.
Usually I will initially use biest, which is 20% oestradiol and 80% oestriol, or a variable percentage combination depending on severity of symptoms and history of oestrogen sensitivity.
Oestriol is considered the "milder" oestrogen, which has more binding affinity for oestrogen receptor beta, which inhibits breast cell proliferation, and may reduce the risk of breast cancer. This effect may be lost if large doses are used. Oestradiol binds equally to both receptors, but has more effect on the uterus than oestriol.
Oestriol has been avalable as an oral tablet and vaginal cream as ovestin for over 30 years in Australia, and considered safe enough to use without any progestagen by most gynaecologists.
 In USA and Europe after 50 years trying to manufacture a synthetic progestogen anywhere as good as progesterone they gave up and Sandoz began marketing progesterone in capsule form about 10 years ago. This is not available in Australia. In my experience capsules do not work well. A large amount is taken up by gut receprors or metabolised before absorption. The metabolites of progesterone can make women very tired. However, in women who have a significant issue with IBS type symptoms it may be of benefit.

Testosterone can be useful for some women, however most women have more available testosterone after menopause. The drop in oestrogen causes a drop in SHBG, the protein that binds and carries oestrogen and testosterone in the blood. As a result there is more unbound, available testosterone. This is why many women develop signs of too much, such as increased facial hair, weight around the middle, and if severe, male pattern balding. I find the majority of women don't need testosterone, however this can be determined by blood tests.

Perhaps the most useful feature of bioidentical hormone therapy is the ability to tailor the dose to individual requirements. I believe in order to do this effectively requires meeting, talking to and examining a person in consultation.