Uploaded June 2026 | Updated September 2026, 3 weeks ago
One of the biggest misconceptions in medicine is people - including doctors - assuming that synthetic hormones are the same as the hormones our bodies naturally produce. They aren’t.
Even a tiny change to a chemical structure can completely change how something behaves. I often use the example of graphite and diamonds. They’re both made from carbon, but their structure is different, and so are their properties.
The same is true for hormones. Synthetic hormones have a different chemical structures to our own natural hormones, which means they behave differently in the body. Yet this distinction is rarely talked about.
This is why there are so many risks (including risks of cancer, clot, heart disease and stroke) with synthetic hormones which are not there with natural hormones that are either prescribed in the body or we prescribe as bioidentical hormone treatments. There is so much unknown about synthetic hormones, even now, as these studies have never been done.
In this week’s episode of my @drlouisenewsonpodcast, I’m joined by Professor Neil Vargesson, whose research has helped uncover the history of Primodos - which contained the synthetic hormones ethinyestradiol and norethisterone - and why the voices of so many women are still going unheard.
One of the biggest misconceptions in medicine is people - including doctors - assuming that synthetic hormones are the same as the hormones our bodies naturally produce. They aren’t.
Even a tiny change to a chemical structure can completely change how something behaves. I often use the example of graphite and diamonds. They’re both made from carbon, but their structure is different, and so are their properties.
The same is true for hormones. Synthetic hormones have a different chemical structures to our own natural hormones, which means they behave differently in the body. Yet this distinction is rarely talked about.
This is why there are so many risks (including risks of cancer, clot, heart disease and stroke) with synthetic hormones which are not there with natural hormones that are either prescribed in the body or we prescribe as bioidentical hormone treatments. There is so much unknown about synthetic hormones, even now, as these studies have never been done.
In this week’s episode of my @drlouisenewsonpodcast, I’m joined by Professor Neil Vargesson, whose research has helped uncover the history of Primodos - which contained the synthetic hormones ethinyestradiol and norethisterone - and why the voices of so many women are still going unheard.
