Licorice (real / black)

Why it matters

Licorice is an unexpected entry, but a well-evidenced one: genuine licorice root contains glycyrrhizin (glycyrrhizic acid), a compound shown in human studies to directly lower testosterone. It also affects the hormones that regulate blood pressure and potassium, so high intakes can raise blood pressure and cause fluid retention. The crucial caveat is what counts as "licorice": many licorice-flavoured sweets are actually flavoured with anise and contain little or no real licorice, while genuine black licorice, licorice-root tea and licorice supplements are the real concern.

What's inside

The active compound is glycyrrhizin (glycyrrhizic acid), which both interferes with testosterone production and inhibits an enzyme involved in cortisol and aldosterone regulation — the latter explaining the blood-pressure and potassium effects. The amount matters: occasional small quantities are unlikely to do much, but regular or large intake of genuine licorice delivers enough glycyrrhizin to matter.

For men

For men, the testosterone effect is direct and documented — regular consumption of real licorice can measurably lower testosterone. For anyone working to support their levels, genuine licorice (and licorice-root tea or supplements) is worth limiting. The good news is that it's an easy one to avoid once you know to check whether a product actually contains licorice root.

For women

For women, glycyrrhizin can disrupt the menstrual cycle and hormone balance, and the blood-pressure and potassium effects apply equally. It's particularly worth avoiding in pregnancy, where higher licorice intake has been associated with adverse outcomes. As with men, the key is distinguishing real licorice from anise-flavoured imitations.

How to eat it

Check labels: if a sweet is flavoured with anise rather than real licorice extract, it isn't the concern here. Limit genuine black licorice, licorice-root teas and licorice supplements, especially in regular or large amounts. If you enjoy the flavour, occasional small amounts are fine for most people — it's the habitual or high intake that matters.

Worth knowing

The real-versus-flavour distinction is the whole story — don't worry about anise sweets, do moderate genuine licorice. People with high blood pressure, heart conditions or who are pregnant should be especially cautious, as the glycyrrhizin effects on blood pressure and potassium can be significant. For most others, it's simply a "don't make it a daily habit" food.

Bottom line

Genuine licorice root directly lowers testosterone and raises blood pressure through glycyrrhizin — so limit real black licorice, licorice tea and supplements, while knowing that anise-flavoured sweets aren't the concern.