Licorice, derived from the root of the Glycyrrhiza glabra plant, is a common herbal remedy and flavoring agent. The primary biologically active compound is glycyrrhizin, which is metabolized in the body to glycyrrhetinic acid. Licorice does not directly stimulate the production of estrogen, but it significantly alters the body’s entire steroid hormone system. Its action on specific enzymes shifts the balance of sex hormones and stress hormones like cortisol. Understanding these biochemical interactions is key to appreciating the herb’s full systemic impact.
How Licorice Affects Hormone Metabolism
The most widely studied hormonal mechanism involves glycyrrhetinic acid and its effect on the enzyme 11-beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2). This enzyme inactivates the potent stress hormone cortisol into its inert form, cortisone, particularly in the kidneys. By inhibiting 11β-HSD2, licorice prevents the breakdown of cortisol, allowing higher concentrations of active cortisol to reach mineralocorticoid receptors. This mimics pseudohyperaldosteronism, which is the root cause of licorice’s well-known side effects, such as high blood pressure and low potassium.
The increase in cortisol activity has cascading effects that impact the entire steroidogenesis pathway. Licorice compounds can also inhibit other key enzymes, such as 17-hydroxysteroid dehydrogenase and 17-20 lyase, which are crucial steps in the synthesis of androgens. Androgens, like testosterone, serve as precursors for estrogen synthesis. This systemic interference demonstrates that licorice is a hormone modulator, rather than a simple estrogen booster.
Clarifying the Effect on Circulating Estrogen
While the idea that licorice dramatically increases circulating estrogen is a common misconception, the herb does contain compounds that exhibit weak phytoestrogenic properties. Flavonoids like liquiritigenin can bind to estrogen receptors, particularly Estrogen Receptor-beta. This activity suggests that licorice components can mimic or modulate estrogen’s effects in certain tissues, but this is not the same as increasing the body’s primary circulating estrogen, estradiol.
The overall impact on measurable estrogen levels is indirect and may even appear anti-estrogenic in some contexts. Licorice extracts interfere with the aromatase enzyme, which is responsible for converting androgens into estrogen. Depending on the specific compounds and tissue involved, this aromatase inhibition can lead to a decrease in local estrogen production. Licorice compounds also influence the liver enzymes responsible for clearing estrogen metabolites, leading to a complex shift in the ratio of different estrogen types.
The most consistent clinical finding regarding sex hormones is the reduction in serum testosterone levels observed in women taking licorice. Since testosterone is a precursor to estrogen, a decrease in this androgen could indirectly limit the raw material available for estrogen production. Licorice’s multifaceted actions—inhibiting androgen-producing enzymes, altering estrogen metabolism, and possessing weak phytoestrogenic qualities—make its effect on overall circulating estrogen levels highly variable.
Comparing Different Forms of Licorice
The critical distinction in discussing licorice’s hormonal effects lies between whole licorice root and deglycyrrhizinated licorice (DGL). Whole licorice root contains the full spectrum of compounds, including the hormonally active glycyrrhizin, which is responsible for the effects on cortisol and blood pressure. Products made from this whole root carry the risk of hormonal and cardiovascular interference described earlier.
DGL is a processed form of the root where the glycyrrhizin component has been intentionally removed to minimal levels. Since glycyrrhizin inhibits the 11β-HSD2 enzyme, DGL is considered safe for long-term use and does not typically cause the elevation in cortisol activity or related blood pressure issues. This form is primarily used for its soothing effect on the digestive tract, without the associated systemic hormonal risk.
Consumers must carefully read product labels to determine the form of licorice being consumed. If a product is labeled as DGL, the hormonal and blood pressure concerns are largely negated. If it is labeled as licorice root extract, glycyrrhizic acid, or contains a high concentration of the whole root, the hormonal and cardiovascular risks remain pertinent. The concentration of glycyrrhizin can vary dramatically, making it difficult to gauge the exact hormonal impact of any given whole-root product.
When Licorice Use Requires Medical Consultation
Due to the effects of glycyrrhizin on the body’s steroid hormone system, specific populations must seek medical consultation before consuming whole licorice. Individuals with pre-existing hypertension or any history of heart, kidney, or liver disease are vulnerable to the blood pressure-raising and potassium-lowering effects of glycyrrhizin.
The hormonal-altering properties of licorice also pose a risk for those with hormone-sensitive conditions. This includes women with:
Hormone-Sensitive Conditions
- Polycystic ovary syndrome (PCOS)
- Endometriosis
- Uterine fibroids
- Hormone-sensitive cancers like certain breast cancers
The potential for licorice compounds to influence estrogen receptors and alter androgen metabolism requires careful monitoring in these cases.
Pregnant women should strictly avoid whole licorice root, as its consumption has been associated with an increased risk of pre-term delivery and negative effects on infant cognitive development. Individuals taking medications that affect potassium levels, such as diuretics or corticosteroids, should also refrain from using whole licorice, as it can exacerbate potassium loss. Medical guidance is necessary to determine a safe consumption limit and duration, especially since hormonal effects can persist for up to a week after discontinuing use.