Taking care of one’s health through plant-based remedies is an approach that is attracting more and more patients. However, the endocrine system operates on the principle of microscopic balances, where the slightest variation can disrupt the overall harmony.The therapeutic use of medicinal plants can profoundly interfere with this internal machinery.
Our body’s chemical messengers govern vital functions: blood sugar management, heart rate, reproduction and foetal development. Introducing plant-based active ingredients without proper monitoring exposes you to major imbalances or critical therapeutic failures. How can one reconcile the use of plants with hormonal regulation without jeopardising one’s health? This guide outlines the essential precautions to take based on your individual profile.
Why does the use of hypoglycaemic plants interfere with hormonal regulation of blood sugar in treated diabetes?
Blood sugar management depends on an extremely precise endocrine balance. Whilst certain plants possess genuine metabolic properties, combining them with conventional treatments creates serious risks of imbalance.
Understanding diabetes according to the WHO
Diabetes is a chronic condition characterised by insufficient insulin production or the body’s inability to use insulin effectively. This leads to hyperglycaemia. Without proper management, it causes serious damage to nerves and blood vessels. It can lead to blindness, kidney failure, heart attacks, strokes or the amputation of lower limbs.
WHO data show that cases of diabetes have quadrupled in a few decades, rising from 108 million to 422 million, with a faster increase in low- and middle-income countries. In 2019, this condition caused 2 million deaths.
There are several types:
- Type 1 diabetes: characterised by a complete lack of insulin, it requires daily injections.
- Type 2 diabetes: this alters the way the body uses glucose (insulin resistance) and is closely linked to being overweight and a lack of exercise.
- Gestational diabetes: this occurs specifically during pregnancy and increases the risk of subsequent type 2 diabetes for both mother and child.
- Prediabetes: glucose intolerance and impaired fasting glucose are early-stage conditions that can progress to type 2 diabetes if no lifestyle changes are made (balanced diet, physical activity, smoking cessation).
The risk of dizziness and hypoglycaemia with gymnema and berberine
In patients with stable diabetes, it is advisable to avoid hypoglycaemic herbs so as not to interfere with existing treatment. Among these, gymnema (Gymnema sylvestre), known as the ‘sugar destroyer’ in India, is renowned for its powerful metabolic properties. It works by reducing the intestinal absorption of sugar and improving insulin secretion. In this way, it alters the hormonal regulation of appetite.
Berberine (found in Berberis vulgaris) is another highly effective compound. It is often compared to Metformin® due to its ability to lower blood sugar, HbA1c and cholesterol.
However, combining gymnema or berberine with oral antidiabetics or insulin creates a dangerous cumulative effect. This can cause blood glucose levels to drop critically. Consequently, it can trigger severe hypoglycaemia.
How do phytoestrogens and algae disrupt the hormonal regulation of the thyroid and hormone-dependent conditions?
Certain plants mimic or block the action of our own hormone receptors. This activity, far from being harmless, is strictly contraindicated in several clinical situations.
Hormone-dependent cancers and xenoestrogens
A hormone-dependent cancer develops when hormones play a direct role in the proliferation of tumour cells. Breast and prostate cancers are primarily affected, as their growth is stimulated by sex hormones that bind to specific receptors present in abnormally high numbers on the surface of the cells. Testosterone stimulates the majority of prostate cancers, whilst oestrogens influence 60 to 70% of breast cancers.
The modern environment, rich in endocrine disruptors (EDs) and ‘oestrogen-like’ or ‘xenoestrogen’ molecules (pesticides, bisphenol A, phthalates, PCBs, DDT, flame retardants or parabens in cosmetics), already contributes to the overstimulation of these tissues. Furthermore, fatty tissues naturally produce oestrogens. People who are overweight are therefore more likely to develop these conditions.
In this context, plants containing phytoestrogens (soya, red clover, hops) should be avoided. Although some research explores a potential protective effect, other studies warn of an increased risk of recurrence when consuming soya-based foods or supplements (rich in isoflavones) in women with a history of breast cancer. As for menopausal symptoms, there is, moreover, no concrete evidence of their effectiveness. Consequently, ANSES recommends caution in children under the age of 3.
Thyroid dysfunction and the iodine trap
The thyroid is a small gland located in the neck that produces the hormones T4 (thyroxine) and T3 (triiodothyronine), which are essential for regulating basal metabolism, oxygen consumption by cells and protein synthesis. The body controls these levels via the hypothalamus and the pituitary gland. The latter secretes TSH (thyrotropin). To function, this gland has a strict requirement for iodine. It absorbs this iodine from water and food.
In cases of thyroid disorders, hormonal regulation is already compromised, whether due to Hashimoto’s thyroiditis (an autoimmune inflammation leading to hypothyroidism, with fatigue, weight gain and sensitivity to cold) or Graves’ disease (hyperthyroidism caused by antibody stimulation, leading to tachycardia, weight loss and insomnia). Consuming medicinal plants or seaweeds rich in iodine (such as fucus) is a major mistake. Indeed, this uncontrolled intake risks saturating or overstimulating the gland. This can further disrupt the thyroid and interfere with medical replacement treatments.
Which plants interfere with hormonal regulation during pregnancy and breastfeeding?
The period of pregnancy and early childhood requires a drastic restriction on herbal medicine. The embryo, and later the infant, are particularly vulnerable to active compounds that cross biological barriers.
Pregnancy and weeks of amenorrhoea: the risks of miscarriage
Gestation refers to the duration of pregnancy from fertilisation to childbirth (approximately 9 months or 273 days). Obstetricians count in weeks of amenorrhoea (w.a.), setting the average duration at 41 w.a. During this period, the stability of the uterine muscle depends on strict hormonal regulation.
In the event of pregnancy, it is essential to avoid plants with emmenagogue or purgative effects, such as:
- Mugwort and sage (which contain ketones such as thujone)
- Marigold and parsley (when consumed in therapeutic quantities)
- Liquorice, senna, rhubarb and buckthorn.
These medicinal plants cause a massive rush of blood to the pelvic organs and stimulate the muscle fibres, which can lead to abnormal uterine contractions and, consequently, a significant risk of miscarriage or premature birth.
Breastfeeding: the transfer of active ingredients into breast milk
Lactation depends on the development of the milk ducts and alveoli, a process greatly influenced by oestrogen and progesterone during pregnancy. After childbirth, prolactin promotes milk production. Furthermore, oxytocin triggers its release. Breast milk undergoes a transformation, starting with colostrum (rich in vital nutrients) and progressing to transitional milk. Finally, it matures to meet the baby’s needs.
Whilst breastfeeding, it is best to avoid taking medicinal plants with purgative, bitter or stimulating effects. The active ingredients in plants cross the breast barrier and pass directly into breast milk. Consequently, this can seriously harm your child by causing severe diarrhoea, colic or liver toxicity in their still-immature
system.
Concerned about your filtering organs? The liver and kidneys are the first to receive plant molecules. Do not overload your system. Find out how to protect your digestive and renal systems when using herbal medicine.
Hormonal regulation relies on extremely delicate physiological balances. Whether managing diabetes, protecting your thyroid, dealing with hormone-dependent cancer or carrying a pregnancy to term, the use of medicinal plants is never neutral. Their powerful active ingredients can dangerously interfere with your hormones or medical treatments. To reconcile herbal medicine with safety, blind self-medication must give way to personalised medical supervision. The informed advice of a healthcare professional is also essential.
Sources:
- ANSES: Expert reports on the safety of soya isoflavones and recommendations for use in pregnant women and young children.
- VIDAL: Herbal medicine during pregnancy and breastfeeding.
FAQ: How can you use herbal remedies without disrupting your hormonal balance?
Why are gymnema and berberine not recommended for people with treated diabetes?
Gymnema and berberine have powerful hypoglycaemic properties. If taken alongside oral antidiabetic treatments or insulin, their effects can accumulate in an uncontrolled manner. This disrupts the hormonal regulation of blood sugar and poses a major risk of severe hypoglycaemic episodes.
What is the risk of consuming soya if you have a history of breast cancer?
Soya contains isoflavones, phytoestrogens that mimic the structure of human oestrogens. As 60 to 70% of breast cancers are stimulated by these sex hormones, the consumption of phytoestrogens can interfere with hormonal regulation. Consequently, this may increase the risk of tumour recurrence.
Why should seaweeds such as fucus be avoided in cases of thyroid disorders?
Seaweeds such as fucus are naturally very rich in iodine. The thyroid gland uses iodine to produce its hormones (T3/T4). Introducing a large amount of iodine via herbal medicine disrupts the gland’s hormonal regulation, which may exacerbate both hypothyroidism and hyperthyroidism.
