Turnera diffusa is the scientific name for damiana, which is sometimes also called herba de la pastora or "old woman's broom." A shrub that grows wild in Mexico and South America, damiana is listed by the U.S. Food and Drug Administration as generally recognized as safe. It is used as a flavoring agent in foods and beverages. It is a popular herbal supplement, and is especially well-known as an aphrodisiac.
According to traditional folklore, damiana effects include heightened sexual response in both men and women, anxiety reduction, lowering of blood sugar, headache relief, and stimulation of menstruation. Damiana has also been used to treat various gastrointestinal disorders, to aid in weight loss, and as both a diuretic and laxative.
The leaves of the damiana plant are harvested for medicinal use. They are often infused into a tea, but are also sold in tincture and capsule form. Some claim that damiana has psychoactive properties, so damiana leaf is sometimes smoked as a recreational drug. Passionflower is said to increase damiana's relaxation effects, and the two are sometimes blended for smoking purposes.
There is little scientific evidence to back up most damiana effects claims. The strongest evidence for damiana's aphrodisiac qualities come from animal studies. The same is also true for claims that damiana lowers blood sugar. Human research has been done on the effectiveness of herbal formulas that include damiana for the treatment of low libido and obesity. While these studies have produced some positive results, it is not known whether the positive results were caused by damiana or the other ingredients.
While the herb is normally considered to be safe for human consumption, some side effects of damiana have been reported. These include mood changes, hallucinations, headaches, and diarrhea. In addition to these damiana effects, there is the possibility of both allergic reactions as well as drug interactions. People who are diabetic or hypoglycemic should avoid using damiana as it may lower blood sugar. Women who are pregnant or hope to become pregnant should avoid damiana as one of its historic uses has been to induce menstruation and miscarriage.
A popular liqueur called Damiana is produced in Mexico using both the leaves and stems of the damiana plant. Some sources say that the original margarita contained Damiana liqueur, tequila, and lime, and that that triple sec was later substituted for the damiana. In homage to the most famous of damiana effects, sexual arousal, the bottle for Damiana liqueur is in the form of a naked, pregnant woman. Damiana is also used in fragrances as well as various scented bath and body care products.