Damiana

Damiana (Turnera diffusa): A Comprehensive Reference

1. Identity, Taxonomy, and Botanical Description

Scientific Names and Taxonomic Classification

Damiana is commercially traded under two Latin names — Turnera diffusa and T. aphrodisiaca — which are generally regarded as the same plant in herbal commerce. The botanical epithet aphrodisiaca directly describes the plant's ancient use as an aphrodisiac. Additional synonyms in the scientific and regulatory literature include Turnera diffusa, T. aphrodisiaca, and T. microphylla. The plant belongs to the family Passifloraceae (formerly Turneraceae under older classifications). A closely related species, T. ulmifolia, is similar in appearance but has different traditional medicinal uses.

Common Names

Damiana is also known as herba de la pastora, Mexican damiana, old woman's broom, and rosemary (not to be confused with the spice Rosmarinus officinalis). Among the Maya, the plant was called mizibcoc. In Mexico it is additionally known as "Damiana de Guerrero," "pastorcita," "hierba del pastor," "hierba del venado," and most commonly "Damiana de California."

Plant Description and Geographic Distribution

Damiana is a shrub occurring in north-eastern Brazil, Mesoamerica, the Caribbean, Mexico, and Texas. It is a Mexican shrub found throughout the southern United States and South America. It has small, yellow-brown, aromatic leaves that are used medicinally when dried. The broadly lanceolate leaves are 10 to 25 mm in length, with 3 to 6 teeth along the margins. The red-brown twigs are often found mixed in the crude drug along with its spherical fruits. Small yellow flowers bloom in early to late summer, which are followed by small fruits with a sweet smell and fig-like flavor. The medicinal part of the plant is its leaves, which are harvested during the flowering season.

Common Preparations and Dosage Forms

Dried damiana leaves are available in tea bags and capsules, and are also sold in tinctures, both alcoholic and alcohol-free. Smoking and inhaling the leaves is practiced but not advised. In Mexico, damiana is used to flavor liqueurs, teas, and other beverages and foods. A mother tincture (85% ethanol extract) of damiana is used as a homoeopathic medicine for the treatment of sexual debility and nervous prostration.

2. Traditional and Historical Use

Mesoamerican Origins

Damiana was recorded to be used as an aphrodisiac in the ancient Mayan civilization, as well as for "giddiness and loss of balance." Its history began with its early use by the Maya (under the name mizibcoc) in the treatment of giddiness and loss of balance. A Spanish missionary first reported that the Mexican Indians made a drink from the damiana leaves, added sugar, and drank it for its purported power to enhance lovemaking.

Indigenous and Colonial Use

Damiana has been traditionally prescribed as a leaf decoction against muscle and nerve weakness, as an aphrodisiac, a tonic, and for catarrhal and bladder inflammations. The leaves of T. aphrodisiaca have been used traditionally as a stimulant, aphrodisiac, tonic, diuretic, nerve tonic, laxative, and in kidney, menstrual, and pregnancy disorders. The leaf infusion of damiana has been used as a traditional remedy in diseases related to the gastrointestinal and respiratory system, reproductive organs, and for the treatment of gonorrhoea in Latin American societies.

Other traditional uses of Turnera species include the treatment of anaemia, bronchitis, cough, diabetes, fever, fungal disease, gastrointestinal complaints, pain, pulmonary and respiratory diseases, skin disorders, and women's health problems. Additionally, Turnera species are used as abortives, expectorants, and laxatives. Damiana has also been used traditionally to improve digestion and to treat constipation, as in larger doses it has a mild laxative effect. Other uses include treatment of asthma, cough and flu, and nephritis.

Brazilian and Regional Use

Damiana is used as an aphrodisiac, an abortive, as an expectorant, and to treat gastric ulcers in the north-east of Brazil. Damiana is also reportedly used as an antidiabetic in Tamil Nadu, India.

Entry into Western Herbal Medicine

The scientific literature on the plant dates back more than 100 years, when reports described its aphrodisiac effects. The British Herbal Pharmacopoeia lists specific indications for damiana as anxiety neurosis associated with impotency, and includes other indications such as depression, nervous dyspepsia, atonic constipation, and coital inadequacy. Damiana extracts with tequila are allegedly used as love potions.

3. Key Constituents and Active Compounds

Overall Phytochemical Complexity

Damiana's chemical composition is complex and its components have not been identified completely. Flavonoids (22 different compounds), maltol glucoside, phenolics, cyanogenic glycosides (7 different compounds), monoterpenoids, sesquiterpenoids, triterpenoids, the polyterpene ficaprenol-11, fatty acids, and caffeine have been found in the genus Turnera.

Volatile Oil

The leaves contain up to 1% volatile oil comprised of at least 20 constituents, including 1,8-cineole, p-cymene, alpha- and beta-pinene, thymol, alpha-copaene, and calamene. The volatile oil content ranges between 0.2–1%, alongside resin (14%), tannin (3.5%), and starch (6%).

Flavonoids

Damiana contains damianin, tetraphyllin B, gonzalitosin I, arbutin, tricosan-2-one, acacetin, p-cymene, β-sitosterol, 1,8-cineole, apigenin, α-pinene, β-carotene, β-pinene, tannins, thymol, and hexacosanol. Among the flavonoids, further separation of active fractions has led to the isolation of naringenin, three apigenin coumaroyl glucosides, and five flavone aglycones. Additional flavonoids and flavonoid glycosides isolated include acacetin, acacetin 7-methyl ether, vetulin, apigenin-7-O-β-d-(6-O-pcoumaroyl)glucoside, echinaticin, tetraphyllin B, tricin-7-glucoside, diffusavone, turneradiffusin, rhamnosylorientin, rhamnosylvitexin, and turneradin.

Cyanogenic Glycosides

Damiana contains tetraphyllin B, a cyanogenic glycoside. In the body, these compounds can release small amounts of cyanide. Cyanogenic glycosides are arguably the most pharmacologically interesting class of secondary metabolites detected in the genus Turnera, particularly with regard to the postulated pro-sexual effects involving the nitric oxide pathway.

Other Notable Compounds

Damiana leaves also contain tannins, flavonoids, beta-sitosterol, damianin (a brown, bitter substance), and the glycosides gonzalitosin, arbutin, and tetraphyllin B. As of 2006, damiana's constituents had not been identified for their effects attributed to the whole herb.

4. Mechanisms of Action

Nitric Oxide / Pro-Sexual Pathway

The pro-sexual activity of damiana has been shown to involve the nitric oxide pathway, with the anxiolytic property of the herb thought to contribute to such effects. The total extract leads to smooth muscle relaxation and, presumably via the NO-cGMP pathway, to a blood flow-enhancing effect, which may intensify arousal. One study discovered that damiana works in a similar way to sildenafil (Viagra), stimulating blood flow through increased nitric oxide production.

Aromatase Inhibition and Hormonal Effects

The extract of Turnera diffusa and two isolated compounds — pinocembrin and acacetin — could significantly suppress aromatase activity, while apigenin 7-glucoside, Z-echinacin, and pinocembrin showed estrogenic activity. The methanolic extract demonstrated a dose-dependent inhibitory activity of the aromatase enzyme with an IC₅₀ value of 63.1 μg/mL. Among 24 tested compounds, pinocembrin and acacetin showed the most potent inhibition with IC₅₀ values of 10.8 and 18.7 μM, respectively. The flavonoids obtained by percolation with methanol, especially the flavanone pinocembrin, were identified as aromatase inhibitors resulting in increased testosterone levels and improved libido. The aromatase inhibitory effect of the total extract may enhance desire by increasing free testosterone.

Anxiolytic Mechanisms

Apigenin, in particular, is known to interact with benzodiazepine receptors in the brain, which may explain damiana's traditional use as an anxiolytic and nerve tonic. An anxiolytic effect was reported in mice given 25 mg/kg orally of a methanol extract of the aerial plant parts of T. diffusa; the effect was reported to be similar to oral diazepam 2 mg/kg. In further studies in mice, apigenin 2 mg/kg extracted from damiana exhibited anxiolytic and analgesic effects. At higher dosages, apigenin extract produced sedative effects.

MAO-B Inhibition

Based on the fact that damiana contains many flavonoids and is traditionally used as a tonic herb, researchers postulated that some components of the plant might be associated with the inhibition of monoamine oxidases (MAOs). In formal testing, acacetin 7-methyl ether showed the most potent selective inhibition of the MAO-B enzyme. Acacetin 7-methyl ether was more than 500-fold selective for MAO-B (IC₅₀ = 0.198 μM) as compared to MAO-A (IC₅₀ > 100 μM). The potency of inhibition of human MAO-B by acacetin 7-methyl ether was approximately four-fold lower compared to the standard drug deprenyl (selegiline), a clinically used drug for the treatment of Parkinson's disease and major depressive disorder, though its selectivity for MAO-B was higher (>500-fold) compared to deprenyl (450-fold).

Gastroprotective Mechanism

Damiana's anti-ulcer activity is believed to be due to the inhibition of lipid peroxidation, immunomodulation, and antioxidant effects of its major constituent, arbutin.

Metabolic / Antidiabetic Mechanisms

Based on traditional use and recent evidence of antidiabetic activity, researchers investigated the effects of a 95% ethanolic extract of T. diffusa leaf on ligand-activated transcription factors — namely PPARα, PPARγ, LXR, and NRF2 — involved in the regulation of metabolic pathways associated with obesity, diabetes, and inflammation, as well as effects on α-glucosidase enzyme, lipid accumulation in adipocytes, and glucose uptake in myocytes. TDE at 50 μg/mL demonstrated a strong agonistic effect on LXR (2.7-fold) and NRF2 (21.6-fold), while the activation of PPARα and PPARγ was in the range of 1.4–1.8-fold under similar experimental conditions. At a concentration of 100 μg/mL, TDE decreased lipid accumulation in adipocytes by 55.3% and increased glucose uptake in muscle cells by 91%.

Estrogenic and Progestogenic Receptor Binding

Researchers determined the binding capacity of plant extracts on estrogen and progesterone receptors in breast cancer cell lines. The hydroalcoholic extract of T. diffusa showed binding to the progesterone receptor; however, in the alkaline phosphatase induction assay, damiana extract neither induced nor inhibited this enzyme, which is why it is considered to have neutral activity on the progesterone receptor.

5. Scientific Evidence by Area of Use

5.1 Sexual Function and Libido

Preclinical Evidence (Animal Studies)

Due to the long history of T. diffusa as an aphrodisiac, both the stimulating effect and the underlying mechanisms are relatively well investigated. In animal testing, the aqueous extract of T. diffusa was found to increase the sexual activity of rats. In sexually sluggish or impotent male rats, damiana increased the number of animals that could achieve ejaculation and decreased the post-ejaculatory interval.

Clinical Evidence (Human Studies)

In contrast to purely preclinical findings, the antiobesity activity was also investigated in a study on healthy human subjects using a herbal preparation containing, among other ingredients, Turnera diffusa leaves. Moreover, the enhancement of female sexual function was assessed in humans; however, the product again contained besides Turnera diffusa other potentially bioactive ingredients.

In one double-blind placebo-controlled study involving 77 participants, 34 women were given the nutritional supplement ArginMax containing damiana extract for four weeks, while 43 received placebos. The women who received ArginMax showed an improvement in sexual desire, reduction in vaginal dryness, and improvement in clitoral sensation. Unlike other uncontrolled studies evaluating damiana's efficacy in women, this study utilized a control group, making findings more suggestive of effectiveness.

Two clinical trials on 185 women of varying ages (22 to 73 years old) reporting a lack of sexual desire examined the effects of ArginMax — a herbal supplement containing damiana, L-arginine, ginseng, ginkgo, multivitamins, and minerals. Supplementation increased sexual desire and satisfaction with overall sex life.

Critical limitation: With respect to ArginMax (which contains L-arginine, ginseng, ginkgo, damiana, multivitamins, and minerals), the Ito et al. study used a 9-item scale, none of which have been validated. The study also indicates that only 3 of 9 items showed more success with the supplement than with placebo, and that the 3 differentiating items varied between the 3 subsets analyzed (premenopausal, perimenopausal, and postmenopausal women). Therefore, the Ito study failed to establish a primary endpoint and concluded success, even though no consistent pattern of success was evident either across subpopulations or across the majority of endpoints. These trials therefore cannot establish damiana as a standalone sexual function agent.

Palacios et al. conducted a pilot study to evaluate the efficacy of the Libicare® supplement on sexual function in postmenopausal women. This supplement consists of a mixture of four herbs, including T. diffusa. Administration of two daily tablets of the supplement for 9 weeks significantly improved five of the six parameters evaluated at the end of the study. Additionally, 86% of patients improved their Female Index of Sexual Function score. There was a significant increase of 0.09 units in the overall testosterone level and a significant decrease in the overall level of sex hormone-binding globulin. The authors associated the increase in lubrication and orgasm parameters with the anti-aromatase activity reported for T. diffusa.

Evidence strength: Most of these activities have so far been investigated only in chemical, cell-based, or animal assays. All existing human clinical data involve multi-ingredient formulations, preventing attribution of effects to damiana alone. No standalone, placebo-controlled human trials of damiana as the sole intervention have been published in the peer-reviewed literature.

5.2 Anxiety and Nervous System Effects

Data from studies done on mice show that damiana reduced anxiety, but human studies are lacking. An animal study found that damiana extract had anxiolytic activity at a dose of 25 mg/kg. Another preclinical study using an apigenin-derived fraction from damiana also demonstrated anxiolytic effects in mice exposed to various animal models of anxiety.

The British Herbal Pharmacopoeia cites indications for damiana's use for anxiety neurosis and depression. Apigenin is an efficacy-determining component of anxiolytic and analgesic activity, and both activities can play an important role — especially the anxiolytic effects that can help clear the head in the context of sexual function.

Evidence strength: Evidence for anxiolytic effects is limited to preclinical (animal and in vitro) models. No controlled human clinical trials have specifically examined damiana's anxiolytic effects as a standalone agent.

5.3 Antidiabetic and Metabolic Effects

The traditional use of T. diffusa in Latin America encompasses usage as an aphrodisiac, a tonic, and for the treatment of diabetes. Regarding antidiabetic activity, conflicting results have been obtained. There is limited evidence from preclinical studies that damiana has hypoglycaemic activity.

Evidence strength: Antidiabetic effects have been demonstrated in cell-based assays and animal models, with conflicting results across studies. No human clinical trials directly assessing damiana's effect on blood glucose or diabetes management have been published.

5.4 Gastroprotective Effects

Damiana's anti-ulcer activity is believed to be due to the inhibition of lipid peroxidation, immunomodulation, and antioxidant effects of its major constituent, arbutin. In Paraíba, Brazil, Turnera diffusa (known locally as chanana) is used for its antiulcerogenic properties.

Evidence strength: Gastroprotective activity has been documented in preclinical models with a proposed mechanism involving arbutin. Human clinical data are absent.

5.5 Weight Management and Appetite

Oral intake of capsules containing a mixture of damiana, yerba mate, and guarana led to weight loss in healthy volunteers. Although there are no controlled studies evaluating the efficacy of damiana as a standalone treatment for weight loss, one study showed that a combination of herbs containing damiana, guarana, and yerba mate increased weight loss in overweight adults after 45 days compared with placebo.

Evidence strength: The single available human study tested a multi-herb combination product; damiana's individual contribution to any observed weight loss cannot be isolated. Evidence is preliminary.

5.6 Cytotoxic / Anticancer Activity

In continuing searches for new cytotoxic agents, extracts, fractions, and pure compounds from damiana have been assayed against multiple myeloma cell lines (NCI-H929, U266, and MM1S). Naringenin and apigenin 7-O-(4″-O-p-E-coumaroyl)-glucoside showed significant cytotoxic effects against the tested myeloma cell lines.

Evidence strength: Cytotoxic activity has been observed in in vitro cell-line experiments only. No animal studies or human clinical trials of damiana for oncological indications have been reported.

5.7 MAO-B Inhibition and Neuroprotective Potential

Several flavonoids from plant sources have been identified as inhibitors of MAO-A and MAO-B. Based on the fact that damiana contains many flavonoids and is traditionally used as a tonic herb, researchers postulated that some components might be associated with the inhibition of MAOs. Besides acacetin, acacetin 7-methyl ether and vetulin also showed selective concentration-dependent inhibition of MAO-B. The MAO inhibitory properties of acacetin have been reported.

Evidence strength: MAO-B inhibition has been demonstrated only in biochemical assays with isolated compounds. Translation of this finding to in vivo human relevance has not been established.

6. Body Systems Associated with Damiana

• Reproductive / Sexual System: For more than a century, damiana's use has been associated with improving sexual function in both males and females.
• Central Nervous System: The plant is particularly used as a stimulant, an aphrodisiac, and generally as a tonic in neurasthenia and impotency, with a long tradition in Central America.
• Endocrine System: A damiana extract, and the compounds pinocembrin and acacetin derived from the herb, suppressed aromatase activity. Other compounds including apigenin 7-glucoside, Z-echinacin, and pinocembrin demonstrated estrogenic activity.
• Gastrointestinal System: Damiana is thought to act as an antidepressant, tonic, diuretic, cough-suppressant, and mild laxative.
• Urinary System: Traditionally, it has been used for treating bladder and urinary issues.
• Metabolic System: Bioactivities experimentally proven for members of the genus Turnera encompass antianxiety, antiaromatase, antibacterial including antimycobacterial, antidiabetic, antioxidant, adaptogenic, antiobesity, antispasmodic, cytotoxic, gastroprotective, hepatoprotective, and aphrodisiac activities.

7. Dosage Forms and Reported Dosages

Clinical studies of damiana use are lacking and do not provide a basis for dosage recommendations. No standardization of preparations exists.

The following dosages have been cited in reference sources, derived from traditional use and commercial preparation labels, not from controlled clinical trials:

• Dried leaf tea: Add 1 cup (250 mL) boiling water to 1/4 teaspoon (1 gram) of dried leaves; steep for 10 to 15 minutes; up to three cups per day.
• Tincture: Take 1/2–3/4 teaspoon (2–3 mL) three times daily.
• Tablets or capsules: 400–800 mg three times per day may also be used.
• Single commercial capsule dose: The dose for one commercial product for adults is one capsule (450 mg) three times daily, preferably with meals.
• Homoeopathic infusion: A traditional infusion preparation of 1 teaspoon per cup of water, taken three times daily, has been cited in naturopathic references.

At least one European review has noted a phytotherapeutically approved drug dosage of one film-coated tablet three times a day (as in the product Remisens®) as a potential reference framework, though this reflects a commercial formulation rather than a standardized clinical dose.

8. Safety Considerations

General Toxicity Profile

Research reveals little or no information regarding toxicity with damiana use. T. diffusa contains potentially toxic chemicals, including arbutin, tannins, and cyanogenic glycosides. The safety of damiana has not been established.

Reported Adverse Events at High Doses

Serious adverse effects including convulsions and other symptoms similar to rabies or strychnine poisoning have been reported after ingestion of 200 grams of damiana extract. Treatment may be symptomatic and supportive care. Cyanogenic glycosides may be present; there is a risk of cyanide toxicity with high doses of damiana.

Cyanogenic Glycoside Risk

Excessive use should be avoided because of the presence of cyanogenetic glycosides and arbutin. Damiana contains tetraphyllin B, a cyanogenic glycoside which, in the body, can release small amounts of cyanide.

Pregnancy and Lactation

In view of the lack of toxicity data and possible cyanogenetic constituents, doses greatly exceeding amounts used in foods should not be taken during pregnancy or lactation.

Drug Interactions — Antidiabetic Medications

Damiana might affect blood sugar levels in people with diabetes. Individuals should watch for signs of low blood sugar (hypoglycemia) and monitor blood sugar carefully when using damiana. Since damiana appears to affect blood glucose levels, there is a concern that it might interfere with blood glucose control during and after surgery; stopping damiana use at least 2 weeks before scheduled surgery has been recommended. No other drug interactions have been formally reported; however, it might potentiate antidiabetic medications.

Absence of Standardization

With only few exceptions, most of the traditional uses and the experimentally verified bioactivities of damiana currently cannot be related to a particular compound or compound class. This means that the consistency and potency of commercial preparations are variable, and no pharmacopeial standards for damiana preparations are currently applied universally.

Regulatory and Food Status

Damiana is approved for food use by the United States Food and Drug Administration (FDA). Damiana is used in foods and is listed by the Council of Europe as a natural source of food flavoring (category N2). This category indicates that damiana can be added to foodstuffs in small quantities with a possible limitation of an active principle (as yet unspecified) in the final product.

Smoking

Some people smoke damiana for a mild euphoria. Smoking herbs generally releases tar, ash, and carbon monoxide, and is not recommended.

9. Summary of Evidence Strength

Very little research has been carried out on the effects of damiana in human subjects, though there are a number of in vivo and in vitro studies that focus on some of its active compounds. About 35 compounds have been identified in damiana, including flavonoids such as apigenin, which have antioxidant properties, and other compounds which may have anti-anxiety and anti-inflammatory properties. There are not many studies on damiana's safety and efficacy in its purported uses, and there is insufficient evidence for any of its supposed benefits. The strongest mechanistic evidence relates to its aromatase-inhibitory and nitric oxide-mediated pro-sexual effects (in vitro and animal models), and its MAO-B inhibitory activity (in vitro only). Human clinical evidence is confined to multi-ingredient supplement trials, limiting attribution of effects to damiana alone.

References

• Cytotoxic Properties of Damiana (Turnera diffusa) Extracts and Constituents and A Validated Quantitative UHPLC-DAD Assay – PMC (MDPI Molecules, 2019)
• Selective Inhibition of Human Monoamine Oxidase B by Acacetin 7-Methyl Ether Isolated from Turnera diffusa (Damiana) – PMC (MDPI Molecules, 2019)
• Pharmacological Evaluation of Bioactive Principle of Turnera aphrodisiaca – PMC
• Bioactivity of the Genus Turnera: A Review of the Last 10 Years – PMC (Pharmaceuticals, 2023)
• Damiana (Turnera diffusa) Reduces Adipocyte Cell Differentiation and Ameliorates Myocyte Glucose Uptake – PubMed (2025)
• Anti-aromatase Activity of the Constituents from Damiana (Turnera diffusa) – ScienceDirect (Journal of Ethnopharmacology, 2008)
• Turnera diffusa Wild (Turneraceae) Recovers Sexual Behavior in Sexually Exhausted Males – ScienceDirect (Journal of Ethnopharmacology, 2009)
• Turnera – ScienceDirect Topics Overview
• Damiana – Memorial Sloan Kettering Cancer Center Integrative Medicine
• Damiana Uses, Benefits & Dosage – Drugs.com Natural Products Database
• Damiana: Health Benefits, Side Effects, Uses, Dose & Precautions – RxList
• Damiana – MedicineNet
• Damiana – Health Information Library, PeaceHealth
• Turnera diffusa – Wikipedia (citing primary phytochemistry sources)
• Damiana – Tropical Plant Database, Raintree Nutrition
• Damiana (Turnera diffusa Willd.) – A Traditionally Used Aphrodisiac as Modern PDE-5 Inhibitor – ResearchGate
• The Use of Natural Products for the Treatment of Female Sexual Dysfunction: A Systematic Review of Randomized Clinical Trials – SCIRP
• Antiphotoaging Effects of Damiana (Turnera diffusa) Leaves Extract – PMC (2022)
• Damiana (Turnera diffusa): Benefits, Safety, Uses – Herbal Reality
• Submission on Un-scheduling Arbutin in Herbal Medicines (Damiana safety data) – Therapeutic Goods Administration (TGA), Australia