When a woman looks for natural options to ease menopause symptoms, it's common to come across products advertised as "phytoestrogenic". But what does that term actually mean, and why can't it be generalised?
What are phytoestrogens?
Phytoestrogens are plant-derived compounds whose chemical structure bears some resemblance to estradiol, allowing them to interact — to a greater or lesser extent — with the body's estrogen receptors. The most studied are soy isoflavones — genistein and daidzein — and the compounds found in red clover.
Why "plant-based" is not synonymous with "hormonally active"
The fact that a substance is plant-derived doesn't automatically mean it has hormonal activity, but it doesn't guarantee the absence of it either. Some plant compounds can bind to the estrogen receptor alpha (ER-α) or beta (ER-β), and the final effect depends on the specific compound, the dose, the target tissue and each woman's individual characteristics.
That's why every plant extract must be evaluated independently: there is no single behaviour for "plant-based" substances as a whole.
Why this matters especially with a history of breast cancer
This distinction is especially relevant for women with a history of hormone-dependent breast cancer, or who are undergoing treatment with tamoxifen, aromatase inhibitors or other oncological therapies.
In these cases, the label "natural" is not enough: it's necessary to know the exact ingredients, their mechanism of action, and the scientific evidence available on the specific extract — not just on the plant it comes from.
EstroG-100: the plant extract in menoelle
EstroG-100, the plant extract present in menoelle, is different from supplements made with soy isoflavones. It's composed of standardised extracts from the roots of Cynanchum wilfordii, Phlomis umbrosa and Angelica gigas.
In the laboratory studies available — assessing receptor binding, transcriptional activation and cell proliferation — this combination showed no significant estrogenic activity, nor relevant affinity for ER-α or ER-β, under the conditions tested.
Transparency: Vive Tu Balance has a commercial collaboration with menoelle. We mention EstroG-100 here because we think it's important to explain precisely what the available evidence says about this specific extract — this collaboration does not replace our critical review, nor does it constitute medical advice. If you have a history of breast cancer, always consult your oncologist before taking any supplement.
How to interpret these results with caution
This experimental result is interesting, but it should be interpreted with caution: it doesn't mean the product has been shown to prevent breast cancer, nor that it can be automatically recommended during active oncological treatment.
Women with a history of breast cancer should review any supplement — however "natural" it presents itself — with their oncologist before starting to use it.
At Vive Tu Balance we believe in clear, rigorous communication: "plant-based", "phytoestrogen-free" and "no demonstrated hormonal activity" are related but distinct concepts, and deserve to be explained precisely.
- EFSA – Panel on Dietetic Products, Nutrition and Allergies (2017). Statement on the safety of EstroG-100™ as a novel food pursuant to Regulation (EC) No 258/97. EFSA Journal, 15(5), e04778.
- Kim, S.J., Jin, S.W., Lee, G.H., Kim, Y.A. and Jeong, H.G. (2017). Evaluation of Estrogenic Activity of Extract from the Herbal Mixture Cynanchum wilfordii Hemsley, Phlomis umbrosa Turczaninow, and Angelica gigas Nakai. Toxicological Research, 33(1), 71–77.
- Kwak, B.Y., Kang, J.K. and Lee, N.J. (2008). Binding Affinity of EstroG to ER alpha and beta using EnBio Estrogen Receptor/Coactivator Ligand Assay System. Research Institute of Veterinary Medicine, College of Veterinary Medicine, Chungbuk National University. (Internal technical report, not published in a peer-reviewed journal.)
- Lee, N.J. and Jeong, Y.R. (2007). Effect of EstroG-100 on the proliferation of MCF-7 cells. Graduate School of Veterinary Medicine, Chungbuk National University / Naturalendo Tech Co., Ltd. (Internal technical report, not published in a peer-reviewed journal.)