Damiana

2010

Historical Note

Damiana is a wild deciduous shrub found in the arid and semi-arid regions of South America, Mexico, United States and West Indies. It is believed that Mayan Indians used damiana to prevent giddiness, falling and loss of balance, and as an aphrodisiac. It has also been used during childbirth, and to treat colic, stop bed wetting and bring on suppressed menses. Today its leaves are used for flavouring in food and beverages, and infusions and other preparations are used for a variety of medicinal purposes.

Common Name

Damiana

Other Names

Herba de la pastora, Mexican damiana, miziboc, old woman’s broom, shepherd’s herb, stag’s herb

Botanical Name / Family

Turnera diffusa, Damiana aphrodisiaca, Turnera aphrodisiaca (family Turneraceae)

Plant Parts Used

Dried leaves and stems

Chemical Components

Sesquiterpenes, alkaloids, essential oils containing caryophyllene, delta-cadinene, beta-elemeneand 1-8 cineol and other lesser constituents, tetraphylin B (a cyanogenic glycoside, 0.26%), resin, tannins, gum, mucilage, starch, a bitter element and possibly caffeine. Damiana also contains a flavone and at least five flavonoids including arbutin.

Main Actions

The pharmacological actions of damiana have not been significantly investigated, so traditional use and in vitro and in vivo evidence is used.

HORMONAL EFFECTS

One study that investigated the effects of over 150 herbs for their relative capacity to compete with oestradiol and progesterone binding to intracellular receptors identified damiana as a herb that binds to intracellular progesterone receptors, exerting a neutral effect and also exerting weak oestrogen agonist activity. It has been reported that delta-cadinene is a testosterone inducer and 1,8-cineole is a testosterone hydroxylase inducer. A study analysing the constituents of the essential oils found in various damiana samples identified that fresh and dry samples contained both compounds, but wild plants contained more delta-cadinene than cultivated plants. The action of these constituents may support the common belief that damiana is useful as an aphrodisiac.

ANTI-INFLAMMATORY ACTIVITY

Significant anti-inflammatory activity was identified for the aqueous and ethanolic fractions of damiana in an experimental model. Antiplatelet activity was not observed.

HYPOGLYCAEMIC AGENT

A decoction of dried damiana leaves caused a significant reduction of the hyperglycaemic peak, exerting a hypoglycaemic effect comparable to that of tolbutamide in an experimental model.

Clinical Use

Damiana has not been significantly investigated under clinical trial conditions; therefore, evidence is derived from traditional use, in vitro and animal studies and clinical significance is unknown.

SEXUAL DYSFUNCTION OR DECREASED LIBIDO

Damiana has been used traditionally for sexual dysfunction or as an aphrodisiac to enhance sexual activity. Scientific studies in experimental models provide preliminary support for its use in these conditions, but controlled trials are lacking. One in vivo study established that damiana fluid extract significantly improves the copulatory performance of sexually sluggish animals, but has no effect on normally functioning ones. The effect appears to be dose-dependent as positive results were only obtained when the highest dose (1 miykg) was administered.

One clinical study of unknown design compared a herbal combination product consisting of ginseng, ginkgo, damiana, l-arginine and a variety of vitamins and minerals with placebo in 77 female volunteers. After 4 weeks, 73.5% of the women in the treatment group reported an increase in sexual satisfaction compared with 37.2% receiving placebo. Although promising, the role of damiana in achieving this result is unknown.

DIABETES

Although in vivo studies suggest significant hypoglycaemic activity, no clinical studies are available to determine whether the effects are clinically significant.

WEIGHT LOSS

No controlled studies are available to determine the effectiveness of damiana as a stand-alone treatment in weight loss; however, one study that used a combination of herbs that included damiana has produced positive results. The randomised double-blind study involving 47 overweight subjects tested a herbal combination product known as ‘YGD’ (Yerbe mate, Paullinia cupana and damiana) for weight loss activity. Treatment resulted in a prolonged gastric emptying time and a body weight reduction of 5.1 ± 0.5 kg compared with 0.3 ± 0.08 kg after placebo over 45 days. A 12-month follow-up revealed that weight loss was maintained in the active treatment group. Until studies using damiana as sole therapy are conducted, the effectiveness of this herb in weight loss is still unknown.

Other Uses

In practice, damiana is sometimes used to treat anxiety and depression associated with hormonal changes (e.g. menopause) or where there is a sexual factor involved. It is also used as a mild stimulant, aphrodisiac, to enhance stamina generally, nervous dyspepsia and constipation.

Dosage Range

• Dried leaf: 2-4 g taken three times daily.

• Infusion: pour a cup of boiling water onto 1 teaspoonful of the dried leaves and let infuse for I0-I5 minutes. Drink 3 cups daily.

• Liquid extract (1:2) or solid dose equivalent: 20-40 mL per week or 3-6 mL/day.

Adverse Reactions

There is insufficient reliable information available.

Significant Interactions

Controlled studies are not available; therefore, interactions are based on evidence of activity and are largely theoretical and speculative.

HYPOGLYCAEMIC AGENTS

Additive effects are theoretically possible, with unknown clinical significance — observe patients.

Contraindications and Precautions

Traditionally, the herb is not recommended for people with overactive sympathetic nervous system activity.

Pregnancy Use

Safety in pregnancy has not been scientifically evaluated however no increase in fetal abnormalities has been observed from limited use in women.

Practice Points / Patient Counselling

• Damiana is a herb with a traditional reputation as being an aphrodisiac, stimulant, mood enhancer and general tonic.

• Currently, evidence to support its use as an aphrodisiac is limited to research in animals, which has produced some positive results.

• In vivo studies have identified significant anti-inflammatory and hypoglycaemic activity, although human studies are still required to determine clinical significance

• It is also suspected that the herb exerts some degree of hormonal activity.

Answers to Patients’ Frequently Asked Questions

What will this herb do for me?

Damiana has not been significantly tested in human studies, so much information is taken from traditional sources or preliminary research in animals. According to these sources, it may increase sexual function and libido in some cases of dysfunction, lower blood glucose levels and exert anti-inflammatory actions.

When will it start to work?

There is insufficient evidence to predict when effects may develop.

Are there any safety issues?

A long history of use suggests it is generally safe. However, scientific testing has not been conducted.