Licorice is the common name for plants of the Glycyrrhiza family. It may contain protective flavanoids. Glycyrrhetic acid (a component of licorice) may decrease testosterone and increase cortisol.
Licorice is most often used for
Licorice (Glycyrrhiza plants, usually the Glabra species) have been used in Traditional Chinese Medicine to fairly good acclaim for various digestive and health problems, and as a general vitality promoting agent. Licorice is also routinely used as a candy product, and is inherently a functional food rather than just a candy (as the oil containing the traditional licorice flavor also contains some bioactive compounds).
One of the most important compounds in Licorice appears to be Glycyrrhizin, which is the sugar-bound form of Glycyrrhetic Acid (there exists both an alpha and beta isomer, with the latter 18β-Hydroxyglycyrrhetic acid being referred to frequently). This compound is highly relevant when consuming pure licorice extracts due to its good absorption and relatively high content, but also underlies a fairly reliable reduction in testosterone and a highly reliable increase in circulating cortisol after consumption. Both of these effects are dose-dependent and not associated with any toxicological effects (and reversed upon cessation of Licorice), but many persons may want to avoid Glycyrrhizin and Glycyrrhetic Acid due to these reasons.
An ethanolic extract of Licorice, sometimes used in supplements, is able to concentrate flavanoids and isoflavanoid compounds with a relatively low Glycyrrhizin content. Some of these flavanoids, including Glabridol as well as the Liquirtigenin class of flavanoids, appear to be the ones that exert properties that would be seen as 'beneficial'.
- Glycyrrhiza Uralensis
- Glycyrrhiza Glabra
Prior to supplementing Licorice, please be aware of Glycyrrhizin (the agent that increases cortisol and reduces testosterone) and, if these results are not desired, try to get products with low Glycyrrhizin content (less than 500mg total dose daily). 150mg has been confirmed to not influence these hormones
Traditional Chinese Medicine recommends a decoction of 8-15g Licorice for health protection and up to 100g for disease states. Consumption of licorice in these doses as a food product does confer the same properties as supplementation, but the caloric and carbohydrate intake from either the root of confectionaries derived from the root need to be accounted for.
With supplementation, intakes of Licorice in the range of 150-300mg daily appear to be most commonly used and intakes of Deglyccyrhizinated (without Glycyrrhizin) up to 1800mg daily for 4 weeks are not associated with toxicity in humans.