Licorice Root's Mechanism in Sport
Licorice root (Glycyrrhiza glabra) contains a primary active compound called glycyrrhizin and its metabolite glycyrrhetinic acid. The most pharmacologically relevant mechanism for athletes is inhibition of the enzyme 11-beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), which normally converts active cortisol to inactive cortisone in peripheral tissues.
By slowing this conversion, licorice root effectively amplifies local cortisol activity without raising cortisol production. The result is a potentiation of mineralocorticoid effects — promoting sodium retention and potassium excretion — and potentially sustained anti-inflammatory cortisol signalling.
For athletes, this dual action is both the potential benefit and the primary risk. On one hand, some practitioners have proposed licorice as a natural support for adrenal function during high-stress training periods. On the other, chronic cortisol amplification carries cardiovascular and hormonal risks that make long-term use unsuitable.
Strength and Endurance Evidence
Direct human research on licorice root for athletic performance is limited. Most evidence is extrapolated from studies examining licorice's effects on cortisol metabolism, electrolyte balance, and adrenal function.
A randomised crossover study found that glycyrrhizin administration altered cortisol metabolism and increased aldosterone-like effects in healthy volunteers (Sigurjonsdottir et al., 2001). The relevance to sport is indirect — sustained cortisol activity may reduce perceived soreness and inflammation after intense exercise, but the same mechanism causes fluid retention and blood pressure elevation at higher doses.
For endurance athletes specifically, the sodium-retaining effect of licorice may theoretically support hydration in ultra-long events, but no controlled trial in athletic populations has been published to confirm this application.
Effective Protocol
If used, doses studied in human research are typically in the range of 100–400 mg of glycyrrhizin-standardised extract daily. Critically, this is not a supplement for extended daily use — the risk of pseudohyperaldosteronism (hypertension, oedema, hypokalaemia) increases significantly with duration and dose.
OstroVit Licorice VEGE 90caps is available at maxfit.ee in the licorice root category. If used, adhere strictly to label guidance and limit use to short cycles with regular blood pressure monitoring.
| Protocol element | Practical recommendation |
|---|---|
| Duration | Maximum 4–6 weeks at a time |
| Monitoring | Blood pressure + electrolytes if used long-term |
| Contraindications | Hypertension, kidney disease, pregnancy, low potassium |
| Cycling | Mandatory — not for continuous use |
Who Benefits and Who Must Avoid
Potential benefit may exist for:
- Short-duration use during periods of high training stress where adrenal support is sought
- Situations where the anti-inflammatory properties of sustained cortisol signalling are relevant
Athletes who should avoid licorice root:
- Those with hypertension or cardiovascular disease
- Anyone on diuretics, corticosteroids, or antihypertensive medications
- Athletes in sports with anti-doping oversight (verify WADA status — glycyrrhizin itself is not banned, but check current lists)
- Pregnant or breastfeeding individuals
- Those with low potassium or kidney conditions
Honest Verdict
Licorice root is a pharmacologically active botanical with real, measurable effects on cortisol and electrolyte metabolism. However, its risk profile is higher than most sports supplements. The evidence base for direct performance enhancement in healthy athletes is absent — the mechanism is interesting, but translating that to improved times or training adaptations lacks controlled human trial support.
For athletes curious about adrenal or recovery support, safer and better-evidenced adaptogens — such as ashwagandha — present a more favourable risk-benefit balance. Licorice root used in short cycles at label doses presents manageable risk for healthy adults without contraindications, but warrants respect for its potency.
FAQ
Is licorice root banned in sport?
Glycyrrhizin, the main active compound in licorice root, is not on the WADA prohibited list as of current available information. However, athletes in tested sports should always verify current WADA and their sport federation's lists before use.
Can licorice root raise blood pressure?
Yes. This is one of the most consistently documented effects of licorice root at doses above approximately 100 mg of glycyrrhizin per day. The effect is reversible on cessation but can be clinically significant, especially in individuals with borderline blood pressure. Regular monitoring is essential.
How does licorice root differ from deglycyrrhizinated licorice (DGL)?
DGL has had glycyrrhizin removed, eliminating the cortisol-modulating and blood pressure effects. DGL is used primarily for gut health (gastric mucosa support) and carries minimal cardiovascular risk. It does not have the adrenal or anti-inflammatory mechanisms relevant to athletic performance discussion.
References
Sigurjonsdottir, H. A., Manhem, K., Axelson, M., & Wallerstedt, S. (2003). Subjects with essential hypertension are more sensitive to the inhibition of 11 beta-HSD by liquorice. Journal of Human Hypertension, 17(2), 125–131. https://pubmed.ncbi.nlm.nih.gov/12574791/
