Damiana Supplements - Safety and Effects
With at least one major vitamin brand adding damiana to its multivitamins for women it is best for people to know what damiana is, what it's used for, and whether or not there are side effects.
Turnera diffusa (synonym Turnera aphrodisiaca) is the herb commonly known as damiana. The plant is a small flowering shrub.
The damiana herb is often used as an aphrodisiac, for depression, respiratory problems, anxiety (although damiana is actually a mild stimulant), and digestive problems.
Evidence That Damiana Works As An Aphrodisiac
One study found that giving mice an aqueous extract of damiana led to increased sexual activity and sexual behaviors in the mice (Arletti et al., 1999).
Another study found that women with a low sex drive and who were between the ages of 22-73 years given ArginMax for women, which contains damiana, L-arginine, ginseng, ginkgo biloba, minerals, and vitamins, reported an increase in sexual desire in comparison to a placebo group (Ito et al., 2006). An earlier study also showed that women taking ArginMax reported an increase in sexual desire compared to a control group (Ito et al., 2001).
It is important to note that estrogen levels are not raised by taking ArginMax and so the increase in sexual desire from taking ArginMax is not due to increased estrogen levels (Polan et al., 2004). Typically people think that sexual desire in women is due to estrogen, however, it is more likely that any increase in sexual desire may be caused from an increase in androgens, although the exact cause of the increased sexual desire after taking ArginMax is unknown. Despite popular opinion, estrogen does very little to increase sexual desire, even in women. It is actually testosterone that influences sexual desire in both men and women.
In another study ArginMax was given to men with erectile dysfunction and it was found that 88 percent of the men taking ArginMax improved (Ito et al., 1998).
Even though both men and women taking ArginMax found that their sexual desire and performance improved, damiana's role in this improvement is not clear. Although ArginMax does contain damiana, the improvement in sexual desire and performance could have been due to the other components entirely.
I could find no research studies using human participants that tested sexual function and desire after taking damiana alone, and so whether or not damiana is an effective aphrodisiac in humans is still unknown.
Side Effects of Damiana
Damiana is generally recognized as safe, however, there haven't been a lot of research studies conducted to test the safety of long-term use or the use of large doses. The Ito et al. (1998, 2001) studies reported no signficant side effects from damiana ingestion, however, these were not long term studies.
There is some evidence that damiana may affect blood glucose levels.
Pregnant women and children should not take damiana or products containing damiana, especially given the possibility that damiana may influence hormone levels.