THE structural1 and pharmacological2–6 similarity between glycyrrhetinic acid and adrenal corticoids has been reported. Glycyrrhetinic acid resembles the corticoids in mineralocorticoid2,3, anti-inflammatory4,5, anti-œstrogenic5 and anti-leukæmic6 activity. Since the glycoside, glycyrrhizin, has an inhibitory action on the pituitary-adrenal system7–9, it was of interest to ascertain whether the aglycone, glycyrrhetinic acid, exerted similar action.