Oestrogen as part of Hormone Replacement Therapy in Menopause.

What are the types of oestrogen, and why is the difference important to our health?

Our bodies make 3 types of oestrogen all of which contribute to our health and vitality. Maintaining an appropriate balance of all three is the key.

The three types are Oestrone, oestradiol and oestriol. If you are reading North American information, estrone, estradiol and estriol are the same compounds.

Please also keep in mind that many articles use the word oestrogen interchangeably with oestradiol for simplicity as this is the most abundant and potent form of oestrogen in our bodies.

Oestrone – E1

As many of you may know, oestrogens are primarily produced in the ovaries. The exception to this is oestrone. It is made in our ovaries, adrenal glands and in our fat cells. Oestrone from the adrenals and fat cells is the main source of oestrogen for children, men and postmenopausal women. Our bodies function better with good levels of oestrogen which is thought to be why we see an increase in fat as we pass through menopause. Those fat cells are trying to ramp up oestrone production! Oestrone can then be converted to oestradiol which is the most potent form of oestrogen in the body.

Unfortunately, when the proportion of oestrone rises we can see various adverse health impacts. This happens during the menopausal period as the ovaries begin to slow production and shut down, however, it can happen at other times when our metabolism is not working well. I will not discuss this here, it is just a little reminder that we need to look after our bodies the best we can or all our systems can be impacted.

As the proportion of oestrone rises we see:

• Weight gain, especially around the waist and abdomen
• Mood swings with a tendency towards feeling weepy or being easily irritated
• Cravings for processed carbohydrates such as sugars
• Fatigue
• Longer and heavier periods

All the symptoms we see associated with perimenopause.

Over time these symptoms diminish as our bodies come into a new setpoint, but sometimes old habits can die hard! We do need oestrone to increase our oestradiol levels, which allows our bodies to function better. Too much and we see the effects above, too little and we see things like osteoporosis. Despite the possible side effects, oestrone does have a purpose, as part of one of the many interconnected webs that make our bodies so amazing.

Oestradiol – E2

The strongest or most bio-active form of oestrogen in the body. This is the type of oestrogen used in conventional menopausal HRT and as part of the oestrogen used in compounded HRT.

Oestradiol is required in both males and females. In males, oestradiol is produced from testosterone and has a major role in bone health, brain health and sexual function.

In premenopausal women, oestradiol is mainly made by the ovaries with amounts varying throughout their cycle. Whilst a woman is pregnant, even more oestradiol is made by the placenta. As we age and pass through menopause, the ovaries stop working, and oestradiol levels drop significantly. Blood levels of oestradiol during ovulation, can be in the thousands compared to levels of less than 50 in postmenopausal women!

Oestradiol impacts many functions in women

• Breast development as we head through puberty (and pregnancy)
• Development of female reproductive organs
• Body shape changes and fat deposition (compare body shapes from childhood to teenagers to reproductive years and then to a postmenopausal woman – it is quite striking.)
• Pregnancy maintenance
• Gut health
• Immune system
• Bone density
• Cardiovascular health – raises HDL (‘good’ cholesterol). So much so that it can be measured in your blood test results during your menstrual cycle.
• Cognitive function (during the first half of your natural cycle you often have better clarity and function, that’s oestradiol)

The sudden low levels of oestradiol and imbalance with progesterone, in the menopausal period, are the cause of hot flushes, night sweats and some of the decrease in your libido. Not to mention forgetting nouns and struggling to stay asleep at night.

Our bodies again adapt to a new set point and the flushes usually diminish and our brains even out, however many of those other functions of oestrogen cannot be met by the conversion of oestrone to oestradiol. This means we start to see osteoporosis, more cardiovascular disease, autoimmune diseases and more women than men with dementia. We simply don’t have the oestrogen (oestradiol) to protect those functions.

Oestriol – E3

Like the other oestrogens, oestriol is made in small amounts in the ovaries from puberty until the onset of menopause. Oestriol blood levels are barely detectable until pregnancy, then the placenta starts to produce bigger amounts, helping the uterus grow and preparing the body for labour and then breastfeeding. During pregnancy, there is an incredible symbiosis with the foetus and the hormone DHEAS. The DHEAS is needed to make oestriol in the placenta as well.
Despite the relatively low levels, oestriol balance is important for keeping mucus membranes moist and your skin supple and functioning well. (For anyone who has experienced vaginal dryness post-birth, the sudden drop in oestriol contributes to this change.)

There is also currently some research into using oestriol in autoimmune diseases such as rheumatoid arthritis and MS, as often the symptoms of these diseases, decrease in late pregnancy when oestriol is the main form of oestrogen in the body.

Oestrogens as part of Menopause and HRT

Oestriol can be used as part of compounded HRT or on its own. Vaginal creams or pessaries used post-menopause can be made from oestriol or oestradiol. Most women find the oestriol creams better for ‘vaginal plumpness’.

Oestradiol is the compound used in all factory-made tablets, patches and creams as part of HRT. As it is the most important oestrogen in the body, it is also the one we need the most to help support our bodies and minimise menopausal symptoms.

Compounded HRT tends to use a combination of oestradiol and oestriol. The reason for doing this is to try and mimic what the body does. Unfortunately, everybody has a slightly different ratio and different needs. This makes us individuals, it also makes HRT trickier.

Oestrone is rarely prescribed, though it was used in the past when the understanding of HRT was more limited.

In summary, there are several types of oestrogens that all have different functions in the body. All are important.
Balancing the ratio of oestrogen in the body can help manage menopausal symptoms.