Benefits
Sexual desire and satisfaction scores in multi-ingredient blend trials
In two 4-week placebo-controlled trials of a blend of L-arginine, ginseng, ginkgo, damiana, vitamins and minerals, more women on the blend than on placebo reported better sexual satisfaction or desire. A larger 12-week trial of the same blend in cancer survivors found no difference in sexual function, its primary outcome. Damiana was one part of the blend, so none of this can be credited to it.
Appetite and meal size with a yerba mate, guarana and damiana blend
In a double-blind crossover trial in 58 women, three tablets of a yerba mate, guarana and damiana blend taken before lunch reduced energy intake at that meal by about 17% compared with conditions without it. This was a single-meal test of a three-herb blend, so the effect cannot be assigned to damiana.
Body weight with a yerba mate, guarana and damiana blend
In 47 overweight adults, three capsules of a yerba mate, guarana and damiana blend before each main meal for 45 days were followed by 5.1 kg of weight loss versus 0.3 kg on placebo, and in 7 volunteers the blend slowed stomach emptying. The trial was small, the authors called for follow-up studies that monitor diet, and the effect cannot be assigned to damiana.
Menopause symptom scores with a four-ingredient formula
In 120 women with menopause symptoms, two capsules a day of a formula of evening primrose oil, damiana, ginseng and royal jelly improved Menopause Rating Scale scores more than placebo over 4 weeks. The damiana dose was not given in the abstract, and its share of any effect is unknown.
Sexual behavior in rodent studies (animal research)
In sexually sluggish male rats, a damiana water extract at 10 mg/kg shortened ejaculation latency, an effect blocked by a nitric oxide synthase inhibitor, and it also reduced anxiety-like behavior. These are animal findings. No trial of damiana on its own has tested sexual function in people.
Aromatase and estrogen activity in laboratory assays (lab research)
In laboratory enzyme assays, a methanol extract of damiana leaf inhibited aromatase, the enzyme that converts testosterone to estradiol, and pinocembrin and acacetin were the most active of 24 isolated compounds. Three compounds also showed estrogen-like activity in a yeast assay. No human study has measured hormones after damiana alone.
Mechanism of action
Nitric oxide signaling in animal sexual behavior
In rats, the pro-sexual effects of a damiana water extract, like those of sildenafil in the same study, were prevented by L-NAME, a blocker of nitric oxide production, and the authors concluded the effect acts mainly in the central nervous system. This is a rat mechanism and has not been shown in people.
Flavonoid effects on aromatase and estrogen signaling (lab)
Damiana leaf extract inhibited aromatase with an IC50 of 63.1 micrograms per mL, and the flavonoids pinocembrin and acacetin did so at 10.8 and 18.7 micromolar. Apigenin 7-glucoside, Z-echinacin and pinocembrin showed estrogen-like activity in a yeast screen. Whether these concentrations are reached after swallowing damiana is not known.
Arbutin and its hydroquinone metabolites
Arbutin has been isolated from damiana infusion. In healthy people given bearberry leaf extract, about 65% of the arbutin dose was excreted in urine as hydroquinone and its glucuronide and sulfate conjugates. How much arbutin damiana products supply was not reported in the sources reviewed.
Clinical trials
Double-blind, placebo-controlled trial of ArginMax for Women, a proprietary blend of ginseng, ginkgo and damiana extracts, L-arginine, multivitamins and minerals, for 4 weeks. The damiana dose, primary outcome and funding are not stated in the abstract (Ito et al. 2001, J Sex Marital Ther)
77 women over age 21 interested in improving sexual function; 34 received the blend and 43 placebo.
73.5% of the blend group improved in satisfaction with their overall sex life versus 37.2% on placebo (p < 0.01), with improvements also reported (without between-group statistics in the abstract) in desire, vaginal dryness, frequency of intercourse and orgasm, and clitoral sensation. No significant side effects were noted. Because damiana was one of many ingredients, the result cannot be attributed to it.
Double-blind, placebo-controlled trial of ArginMax for Women (L-arginine, ginseng, ginkgo, damiana, multivitamins and minerals) for 4 weeks, with results reported by self-reported menopausal status. The damiana dose and funder are not stated in the abstract (Ito et al. 2006, J Sex Marital Ther)
108 women aged 22 to 73 reporting a lack of sexual desire (59 premenopausal, 20 perimenopausal, 29 postmenopausal); 55 received the blend and 53 placebo.
Compared with placebo, premenopausal women reported improved level of desire (72%, p = 0.03) and satisfaction with overall sex life (68%, p = 0.007); perimenopausal women reported more frequent intercourse (86%, p = 0.002) and better relationship satisfaction; and 51% of postmenopausal women reported more desire versus 8% on placebo (p = 0.008). Results are subgroup comparisons, and damiana was one part of the blend.
Randomized, triple-masked, placebo-controlled trial (NCT00459134) of ArginMax (L-arginine, ginseng, ginkgo, damiana, multivitamins and minerals), 3 capsules twice daily for 12 weeks; primary outcome FSFI sexual function at 12 weeks; funded by an NCI grant and The Daily Wellness Company, which supplied the product and placebo (Greven et al. 2015, J Community Support Oncol)
186 women, median age 50, at least 6 months after cancer treatment (78% breast, 12% gynecologic) reporting problems with sexual interest, satisfaction and functioning.
The primary outcome showed no benefit: at 12 weeks there were no differences between blend and placebo in sexual desire, arousal, lubrication, orgasm, satisfaction or pain. The secondary FACT-G quality of life score was higher on the blend (87.5 versus 82.9, p = 0.009). Side effects were similar in both groups.
Three parts: a placebo comparison of gastric emptying by ultrasound, a 10-day placebo comparison, and a 45-day double-blind, placebo-controlled parallel trial of three YGD capsules before each main meal, followed by 12 months of uncontrolled use; funding is not stated in the abstract (Andersen et al. 2001, J Hum Nutr Diet)
7 healthy volunteers (gastric emptying), 44 overweight patients (10 days) and 47 overweight patients (45 days) at a primary care center; 22 continued for 12 months.
Gastric emptying took 58 minutes after YGD versus 38 minutes after placebo (p = 0.025). Weight fell 0.8 kg versus 0.3 kg over 10 days and 5.1 kg versus 0.3 kg over 45 days. In the uncontrolled 12-month phase, weight held steady (73 kg to 72.5 kg). This is a three-herb blend, so damiana's part is unknown.
Double-blind, placebo-controlled crossover trial of a patented yerba mate, guarana and damiana (YGD) formulation (3 tablets) and an inulin fiber, alone or together, taken 15 minutes before an ad libitum lunch; funding is not stated in the abstract (Harrold et al. 2013, Appetite)
58 normal to slightly overweight women.
When YGD was present, food intake at lunch fell by 59.5 g (16.3%) and energy intake by 112.4 kcal (17.3%) compared with conditions without it; the lowest intake was with YGD plus fiber, which also lowered hunger ratings. These are single-meal effects of a three-herb blend, not of damiana alone.
Randomized, placebo-controlled trial of Lady 4, two capsules daily for 4 weeks, with the Menopause Rating Scale II as the outcome; the damiana dose and funding are not stated in the abstract (Yakoot et al. 2011, Forsch Komplementmed)
120 women with menopausal symptoms.
MRS-II scores improved in both groups at 2 and 4 weeks, more with Lady 4 (p < 0.001); 86.7% on Lady 4 and 56.7% on placebo rated the result much or very much improved. This is a four-ingredient product, so the result cannot be credited to damiana.
Exploratory, prospective, non-controlled observational study of Libicare, 2 tablets daily for 2 months, supplying 150 mg of dried damiana extract along with fenugreek, tribulus and ginkgo extracts; primary endpoint change in FSFI score from baseline; retrospectively registered (ISRCTN12928573); no funding obtained; Libicare is made by Procare Health, one author is a Procare Health Iberia researcher with financial ties to the company, and two others report consulting or speaker fees from it (Palacios et al. 2019, BMC Womens Health)
29 postmenopausal women aged 45 to 65 (mean 54.7) with FSFI scores below 25.83.
FSFI score rose from 20.15 to 25.03 (p = 0.0011), with the largest gain in desire. In 21 women, testosterone rose from 0.41 to 0.50 pg/mL and SHBG fell from 85 to 73 nmol/L. With no control group, these changes cannot be separated from expectation or normal variation, and they cannot be credited to damiana alone.