Natural or synthetic hormone treatment (HRT): understanding the difference
Synthetic hormone treatment (HRT) and natural hormone replacement therapy - learn the differences
If you’ve been prescribed hormone treatment, do you know whether it contains natural (sometimes called ‘body identical’) hormones or synthetic hormones? Or why it might make a difference?
What are natural hormones?
Most Newson Clinic patients are prescribed natural, body identical hormones. This means the hormone – estradiol (estrogen), progesterone and/or testosterone – has the same chemical structure as those produced by your body. These natural hormones are derived from the yam plant or soy.
What is synthetic hormone treatment (HRT)?
Synthetic hormones differ chemically from the hormones produced by your body. This means they may have different metabolic effects on your body.
You may be aware that the original synthetic estrogen tablets contained a mix of several types of estrogen that was derived from pregnant horse urine. There are other types of tablet estrogen that also have a different chemical structure to that of estradiol, which is the beneficial type of estrogen your body produces before menopause.
Synthetic versions of progesterone are called progestogens, or progestins. These both have a slightly different chemical structure to progesterone. Progestogen is a molecule, either natural or synthetic, which has similar effects to progesterone and binds to the progesterone receptor. Progestins are synthetic compounds, they are made in a laboratory, which mimic the action of progesterone.
All forms of testosterone hormone treatment is body identical hormone treatment – there are no synthetic versions.
What’s the difference between natural and synthetic hormones?
The safest type of hormone treatment is natural, bioidentical (body identical) hormone treatment .
Natural, body identical estradiol has fewer side effects than synthetic estrogen and has no risk of blood clot or stroke (estrogen tablets have a small increased risk of clot or stroke) [1]. This is because when estrogen is taken as a tablet, it is metabolised in your liver, which produces clotting factors.
Natural, body identical progesterone has fewer side effects than other types of progestogens and is not associated with risks to your health – studies have shown that women who take micronised progesterone (Utrogestan) do not have a higher risk of clot or heart disease [2].
Synthetic progestogens and progestins are associated with a small risk of blood clot, heart disease and breast cancer. Your individual risk will depend on your overall health, genetics, family medical history, weight and your lifestyle habits. For instance, the risk of breast cancer is greater in women who are overweight, do no exercise or drink moderate amounts of alcohol compared to taking any types of hormone treatment[3].
To learn more about synthetic and natural hormones, read Dr Louise Newson's article here.
If you are thinking of changing your type of hormone treatment, you can book consultation below.
Is my hormone treatment (HRT) natural or synthetic?
If you take your estrogen through your skin – as a patch, gel or spray – this is natural estradiol.
There are some estrogen tablets that contain natural estradiol, such as Elleste Solo and Zumenon, but there remains a small increased risk blood clot [1] because it is in tablet format. Other types of tablet estrogen are classed as synthetic hormone treatment (bio identical hormone treatment).
Micronised progesterone (progesterone that has been ground to a fine powder and suspended in oil) is body identical or natural. This includes Utrogestan and Gepretix.
Although not classed as body identical, the Mirena (and Levosert) coil is a safe and effective type of progestogen – it has the least side effects and risks compared to other types of progestogens and it usually just works locally on the lining of your womb.
In combined hormone treatment – a patch or a tablet that contains both estradiol and progestogen – the estradiol is natural but the progestogen is synthetic. An exception is Bijuve, a tablet that contains both natural estradiol and progesterone.
At Newson Clinic, the most common type of hormone treatment we prescribe are body identical hormones. You can learn more about them in Dr Louise Newson's article here.
Should I change my hormone treatment (HRT) type?
Your Newson Clinic healthcare professional can work with you to determine the best hormone treatment type for your individual circumstances. If you were prescribed synthetic hormone treatment (bio identical hormone treatment) some time ago, you may want to discuss alternative options with a clinician at Newson Clinic.
Keep in mind that there is no ‘best’ option that suits all women. Some women, for example, are progesterone intolerant and find that their mood is lower when they take Utrogestan or they experience side effects. In this case, it is worth talking to your Newson Clinic healthcare professional who may discuss alternative ways of taking Utrogestan, or alternative options.
