Licorice Root for PCOS: The Anti-Androgen Claim and the Real Risk

Why Is Licorice Root Sold as a PCOS Treatment?

Licorice root is marketed for PCOS on the claim that it lowers testosterone, and that claim traces to a single small trial. Nine healthy women aged 22 to 26, in the luteal phase of their cycle, took 3.5 g daily of a commercial licorice preparation containing 7.6% glycyrrhizic acid — roughly 266 mg of the active compound a day — for two menstrual cycles. Total serum testosterone fell from 27.8 to 19.0 ng/dL in the first month and 17.5 ng/dL in the second (p < 0.05), and returned to baseline after they stopped. The study’s own authors speculated licorice “could be considered an adjuvant therapy of hirsutism and polycystic ovary syndrome” — a hypothesis from a nine-person trial in healthy women without PCOS, not a finding replicated since in anyone who actually has it. That is the entire human evidence base the PCOS marketing rests on: one trial, nine people, no PCOS diagnosis among them.

What Does Glycyrrhizin Actually Do to Blood Pressure and Potassium?

Glycyrrhizin blocks an enzyme called 11β-hydroxysteroid dehydrogenase type 2, which normally inactivates cortisol inside the kidney before it can reach receptors meant to respond to aldosterone, the hormone that controls sodium and potassium balance. Block that enzyme and cortisol piles up and activates those receptors anyway, telling the kidney to retain sodium and water and flush out potassium — a state called pseudohyperaldosteronism, because it mimics excess aldosterone without aldosterone actually being elevated. A 2006 regulatory toxicology review of the full pharmacology literature describes the downstream picture plainly: continuous, high-level glycyrrhizin exposure produces hypermineralocorticoid-like effects in both animals and humans, reversible once licorice or glycyrrhizin is stopped. In practice that means rising blood pressure and falling blood potassium, and both move together because they share the same mechanism.

A 2021 narrative review synthesising the clinical risk factors adds a second layer: not everyone reacts to the same dose the same way, and several identifiable factors — high daily dosage, long-term use, chronic constipation (which lets gut bacteria convert more glycyrrhizin into its active form), low blood albumin, impaired bile clearance, older age, and taking a diuretic alongside it — all independently raise the odds of licorice-induced pseudoaldosteronism at a given intake. That variation is the practical reason a dose someone else tolerates without incident is not a guarantee you will.

What Dose and Duration Have Actually Caused Harm?

There is no dose of licorice root proven safe for everyone, and the documented harm spans a wide range of intakes and durations rather than one clean threshold. The FDA’s consumer warning on black licorice — issued by name as “Black Licorice: Trick or Treat?” — states that eating two ounces of black licorice a day for at least two weeks can be enough to cause an irregular heart rhythm in adults 40 and older, through the same potassium-lowering mechanism described above; it also advises anyone of any age against eating large amounts at once, and to stop immediately and call a doctor at the first sign of irregular heartbeat or muscle weakness. NIH’s National Center for Complementary and Integrative Health puts the pregnancy-specific threshold even lower: consuming roughly 250 g of licorice a week during pregnancy has been associated with a higher risk of delivery before 38 weeks of gestation.

Case reports fill in what happens past those thresholds. A 65-year-old woman with previously well-controlled hypertension developed a hypertensive crisis, with blood pressure readings in the 200s over 140s, after eating two to four boxes daily of an old-recipe licorice candy for six months — she required seven days in hospital, five of them in intensive care, and a three-drug regimen before her blood pressure came back under control. A 49-year-old woman developed facial and leg swelling, hypertension, and fatigue after three weeks of drinking licorice herbal tea bought online, with blood tests showing a potassium of 3.1 mmol/L and suppressed aldosterone — a laboratory signature consistent with pseudohyperaldosteronism rather than a true aldosterone-driven cause. Separately, a case report describes severe hypokalemia-induced rhabdomyolysis attributed to licorice consumption, the muscle-breakdown complication that can follow when potassium falls far enough. And in September 2020, the New England Journal of Medicine published the case of a 54-year-old man who died of sudden cardiac arrest after a period of heavy black licorice consumption, with severe hypokalemia identified as the mechanism connecting the two — the case that anchors the FDA’s own warning about this ingredient.

Notice what the table does not show: a single dose that is safe for everyone below it and dangerous for everyone above it. The 6-month candy case and the 3-week tea case both caused clear harm at different intakes; the fatal case involved sustained heavy use; the pregnancy threshold is lower still. Combined with the individual risk factors in Table 1, this is a substance where “I’ve had this amount before with no problem” is not a reliable predictor of the next exposure.

What Do These Harms Actually Feel Like, and When Is It Urgent?

A rising blood pressure from licorice does not always announce itself, but when it does, expect a headache, visual disturbance, or a pounding feeling in the head or chest — the same presentation as a hypertensive crisis from any cause, which is what one of the case reports above became. Low potassium shows up as muscle weakness, cramping, or an unusual, out-of-proportion fatigue, and can progress to heart palpitations or an irregular heartbeat as it worsens — the exact mechanism behind both the FDA’s warning and the fatal case above. Edema from sodium retention looks like swelling in the face, hands, or lower legs that was not there before, and rhabdomyolysis — muscle breakdown from severe, prolonged potassium loss — presents as severe muscle pain and dark, tea-coloured urine, and is a same-day emergency, not a wait-and-see symptom.

DGL Is a Different Product — and This Is the Distinction That Matters

Deglycyrrhizinated licorice (DGL) is manufactured specifically to strip out glycyrrhizin, the compound responsible for everything described above. NIH’s own fact sheet reflects that distinction directly: it warns about glycyrrhizin causing irregular heartbeat and cardiac arrest at high or prolonged intake, while separately noting that licorice products without glycyrrhizin — DGL — might be safe for up to four months of use. That is a real safety improvement, and it is also the reason DGL cannot simply be substituted in for “licorice root” in the PCOS conversation: the one human trial showing a testosterone effect used a standard, glycyrrhizin-containing preparation, not a deglycyrrhizinated one. No trial has tested DGL for androgen levels, hirsutism, or any other PCOS outcome. A product manufactured to remove the compound responsible for the harm has, as far as the evidence shows, also removed the only mechanism the PCOS claim was ever tested on. DGL is a genuinely different product with a different, narrower, and better-supported use case — mainly digestive, for reflux and ulcer symptoms — not a safer version of the same PCOS supplement.

Who Should Not Take Licorice Root With Glycyrrhizin at All

Licorice root containing glycyrrhizin is contraindicated in pregnancy, given the preterm-delivery association above; in existing hypertension, since the entire mechanism raises blood pressure further; in kidney disease, because impaired potassium and fluid handling compounds the drug’s own effect; and in heart failure, where sodium and fluid retention can worsen an already strained heart. It also interacts meaningfully with several medication classes: diuretics compound the potassium loss through a second route; digoxin’s toxicity risk rises as potassium falls, since low potassium sensitises the heart to digoxin’s effects; corticosteroids add to the same cortisol-driven mineralocorticoid pathway glycyrrhizin is already activating — an interaction NIH’s own fact sheet specifically flags; and any blood pressure medication is working against an ingredient actively raising blood pressure through an unrelated mechanism, which can make the medication’s effect unpredictable.

Is Licorice Root a Natural Alternative to Spironolactone?

No, and the honest comparison is not about strength but about the safety net. A 2023 meta-analysis conducted to inform the current international guideline found anti-androgens including spironolactone improved hirsutism more than metformin, but were not shown superior to placebo outside that comparison, and are positioned as an option once combined contraceptives are contraindicated, poorly tolerated, or have not worked after a minimum six-month trial — a conclusion the 2023 international guideline itself reaches. What spironolactone’s own trial evidence and potassium data actually show is a prescription drug with a real, studied effect, dosed by a clinician, and monitored with blood tests specifically because of its own potassium risk. Licorice root offers none of that infrastructure: no clinician deciding the dose, no blood test schedule, no one adjusting course if potassium starts moving in the wrong direction — and, as the case reports above show, it can move quickly once it does. The everyday version of “natural” here is not lower-risk; it is unsupervised.

Who This Will Not Help

If you are looking for a gentler, side-effect-free alternative to a prescribed anti-androgen, licorice root is not that: its only human evidence for lowering testosterone comes from nine healthy women without PCOS, and its documented harms include hospitalisation and a reported death. If you are drawn to DGL as a “safe version” of the same supplement, the evidence does not support that either — DGL has not been tested for any PCOS outcome, because the compound the original claim rests on is exactly what DGL removes. And licorice root, in any form, does nothing for the insulin resistance, irregular cycles, or metabolic features of PCOS; its entire claimed relevance here is a single hormonal marker in a nine-person trial. A fuller list of supplements with a real safety flag in PCOS covers where licorice sits among other commonly recommended options, and a broader interaction check across what you may already be taking is worth running before adding anything with this mechanism to an existing regimen. If a milder, better-studied anti-androgen botanical is what you are actually after, the evidence behind saw palmetto is a different, and separately modest, story.

You may see PCOS written as polyendocrine metabolic ovarian syndrome (PMOS), after a 2026 global consensus of more than 50 organisations renamed it. Nothing about glycyrrhizin’s mechanism or the harms above changed with the name — this article uses PCOS because that is still what most readers search.