IngredientesYerba santa, most commonly identified as Eriodictyon californicum (Hook. & Arn.) Torr., is a species in the family Namaceae. It is a perennial evergreen shrub native to California and Oregon. The common name "yerba santa" is applied to several species within the genus Eriodictyon; the three most abundant and commonly used are E. californicum, E. angustifolium, and additional narrowly distributed species. The genus name Eriodictyon derives from Greek, meaning "woolly net," referring to the fuzzy underside of the leaves.
The taxonomic placement of this genus has shifted over time. It belongs in the Hydrophyllaceae, or Waterleaf family; however, with taxonomic changes, this family may be subsumed into the Boraginaceae, or Borage family. Some sources now place it in the family Namaceae. Other investigated species in the genus include E. trichocalyx, E. crassifolium, E. tomentosum, E. traskiae, and E. capitatum.
Synonyms encountered in older pharmacological and botanical literature include Eriodictyon glutinosum Benth. and Wigandia californicum Hook. & Arn.
Recognized common names include Bear Plant, Bear's Weed, Consumptive's Weed, Gum Bush, Holy Weed, Mountain Balm, Tarweed, and Yerba Santa. The name "Santa Herba" (or "Herba Santa") is also used, particularly in European commercial contexts. In French, the plant is sometimes referred to as Herbe Sacrée, Herbe Sainte, or Herbe des Montagnes.
Yerba santa is an evergreen aromatic shrub with woody rhizomes, typically found in clonal stands growing to a height of 3 to 4 feet (0.91 to 1.22 m). The dark green, leathery leaves are narrow, oblong to lanceolate, and up to 15 centimeters (5.9 in) in length. Foliage and twigs are covered with shiny resin and are often dusted with black fungi, Heterosporium californicum. The leaves are tough and leathery, simple, long (3 to 4 inches), and slender (lanceolate), often sticky with resin, with alternate arrangement along the stem. The flowers are white to lavender or purple, and shaped somewhat like little trumpets.
Eriodictyon californicum is native to California and southwestern Oregon, where it grows in chaparral habitats of the coastal and interior mountains.
Eriodictyon californicum is ranked G4 globally and is not ranked at the federal or state level. Eriodictyon capitatum is ranked G2 globally, N2 Endangered at the federal level, and S2 at the state level; it is endemic to Santa Barbara County and is only known from three locales. Because the various species of Eriodictyon have been referred to as "yerba santa," including species that are threatened or endangered, it is important to fully characterize each species and develop basic standards for ensuring the identity, quality, and consistency of yerba santa raw material and finished products.
The leaf is the primary part used medicinally. Preparations reported include:
Various parts, and primarily the leaves, of yerba santa have traditional medicinal use among the Atsugewi, Coahuilla, Coastanoan (Ohlone), Karok, Kawaiisu, Mahuna, Mendocino, Miwok, Pomo, Round Valley, Yokut, and Yuki Indigenous groups of the western United States. The Indian tribes of south coastal California, including the Kumeyaay of San Diego and northern Baja California, and the Chumash of the Santa Barbara area, used several species of yerba santa extensively for respiratory ailments and general aches and pains.
Several California Native American tribes used the plant to treat colds, upper respiratory infections (including whooping cough, pneumonia, and tuberculosis), asthma, rheumatism, and externally to treat sores. The Spanish came to know of its medicinal value through Native Americans, who either smoked or made infusions of yerba santa.
Native Americans made a tea or syrup of the leaves for treatment of respiratory illnesses, coughs, and fevers, or they made a poultice for external ailments. Foliage from the yerba santa plant was applied directly to the skin as a poultice, and in this manner the uses ranged to a remedy for sprains, bruises, and joint pain.
Yerba santa was traditionally brewed into a tea, eaten, or used as a poultice after it was harvested in the fall when the leaves are at their stickiest. All parts of the plant were utilized, including the leaves, flowers, and stems.
The plant was encountered by Spanish missionaries who came to California, and legend has it that it was introduced to Spanish priests at Mission San Antonio de Padua by the Salinan tribe. It was so revered for its medicinal properties and ability to treat respiratory illnesses that Spanish missionaries deemed it a "holy herb."
By 1875, yerba santa was included in the Eclectic Medical Journal, and it was listed in the Pharmacopoeia of the United States in 1894. In the United States and Britain, yerba santa was formally used for conditions including influenza, bacterial pneumonia, asthma, bronchitis, and tuberculosis starting in the late 1800s until the 1960s, when drug regulations became more stringent around proof of efficacy.
Subsequently, the extracts remained on the GRAS ("Generally Regarded as Safe") list as a flavor for foods, beers, and pharmaceuticals, such as to hide the bitterness of quinine. In Germany, the herbal drug is solely a substance for homeopathic preparations.
The traditional preparation that became widely adopted in mainstream American herbal practice mirrored Indigenous methods: the thick sticky leaves, used either fresh or dried, were boiled to make tea or taken as treatment for coughs, colds, asthma, and tuberculosis. Yerba santa was also applied directly to the skin in a warm dressing (poultice) to treat bruises, sprains, wounds, insect bites, and to relieve joint pain (rheumatism).
In foods and beverages, a fluid extract of yerba santa is used as a flavoring component. This application predates modern research into its taste-modifying properties.
The most pharmacologically significant chemical class in yerba santa is the flavanones. Identified pharmacologically active flavanones include eriodictyol, homoeriodictyol, pinocembrin, sakuranetin, naringenin 4′-methyl ether, and 7-methoxy-3′,4′,5-trihydroxyflavanone (also known as sterubin).
Sterubin (7-methoxy-3′,4′,5-trihydroxyflavanone) is now recognized as the major bioactive compound of the genus. The neuroprotective properties of extracts prepared from Eriodictyon taxa leaves correlated with the amount of sterubin, but not with eriodictyol or homoeriodictyol, indicating that sterubin is the major active compound across Eriodictyon species. The Californian plant Eriodictyon californicum produces the flavanone sterubin as its pure (S)-enantiomer.
Homoeriodictyol (3′-methoxy-4′,5,7-trihydroxyflavanone) is notable for its taste-modifying properties. Homoeriodictyol is a bitter-masking flavanone extracted from yerba santa (E. californicum). It is one of four flavanones identified in this plant eliciting taste-modifying properties.
Eriodictyol (3′,4′,5,7-tetrahydroxyflavanone) is structurally very close to sterubin, differing by a single methoxy group, and exhibits somewhat lesser neuroprotective activity but retains antioxidant and anti-inflammatory properties.
Four active flavones have also been isolated from E. californicum: cirsimaritin, chrysoeriol, hispidulin, and chrysin.
Several biologically active phytochemical constituents have been isolated from leaf extracts of E. californicum and identified, including the polyphenolics rosmarinic acid, salvianolic acid H, melitric acid A, and eriolic acids A–D.
A 2010 study using sensory-guided fractionation identified a series of novel bisprenylated benzoic acids: erionic acids A, B, C, D, E, and F, and eriolic acids A, B, C, and D, along with the known flavonoids eriodictyol, homoeriodictyol, hesperetin, and chrysoeriol.
The major essential oil components in E. californicum were identified as 1,8-cineole (0.6–35.5%), (Z)-β-ocimene (6.8–15.7%), terpinen-4-ol (8.3–16.1%), α-pinene (2.6–13.6%), β-phellandrene (1.9–11.7%), γ-terpinene (4.6–7.9%), ethyl (E)-cinnamate (0.2–8.9%), α-terpineol (1.5–5.2%), p-cymene (2.0–5.3%), and β-pinene (0.6–6.8%). The presence of 1,8-cineole (also known as eucalyptol) at high concentrations is consistent with the plant's traditional use as a respiratory herb.
Qualitative studies have confirmed the presence of saponins, phlobatannins, phenols, tannins, terpenoids, cardiac glycosides, steroids, and flavonoids in yerba santa. The leaves were found to be rich in phenol content (78.58 ± 0.016 μg GAE/mg) and flavonoid content (6.76 ± 0.003 μg QE/mg).
Using UHPLC/ESI/Q-ToF data and protonated, deprotonated, and adduct and fragment ions in positive and negative ion modes, researchers were able to identify 53 compounds in yerba santa plant samples.
Sterubin is highly protective against multiple initiators of cell death that activate distinct death pathways, potently induces the antioxidant transcription factor Nrf2, and has strong anti-inflammatory activity. The Nrf2 pathway is a master regulator of endogenous antioxidant defenses. Moreover, in a short-term model of Alzheimer's disease, sterubin was able to prevent decreases in short- and long-term memory.
Yerba santa has long been known for its anti-inflammatory properties, and in phenotypic screens, sterubin was found to have potent anti-inflammatory activity in BV-2 microglial cells, whereas eriodictyol was less effective and homoeriodictyol had no effect at concentrations up to 10 µM.
At a concentration of 1.0 mg/mL, the leaf extract of E. californicum showed 93.39% inhibition of DPPH radicals, 57.36% inhibition of superoxide radicals, and 80.89% inhibition of hydroxyl radicals. This study reveals that E. californicum leaves are a rich source of antioxidants.
In sensory studies, the flavanones homoeriodictyol, its sodium salt (homoeriodictyol sodium salt), sterubin, and eriodictyol could significantly decrease the bitter taste of caffeine without exhibiting intrinsic strong flavors or taste characteristics. Homoeriodictyol sodium salt elicited the most potent bitter-masking activity by reducing from 10 to 40% the bitterness of salicin, amarogentin, paracetamol, and quinine.
The molecular mechanism has been partly characterized: the sodium salt of homoeriodictyol (Na-HED) is known to be an antagonist of bitter taste receptors TAS2R20, TAS2R31, TAS2R43, and TAS2R50, and an agonist of TAS2R14 and TAS2R39.
In vitro and in vivo models showed that an E. californicum extract binds to the adenosine receptor A2A (ADORA2A), stimulates Caenorhabditis elegans motility (+7.5%) and locomotion, and yields high antioxidative capacities. Binding to ADORA2A is mechanistically similar to the pathway by which caffeine exerts energizing effects, making yerba santa a possible natural adenosine receptor modulator.
Flavonoids including sterubin, eriodictyol, homoeriodictyol, hesperidin, and luteolin are recognized for their role in supporting weight management and metabolic health. Studies show that these compounds modulate lipid metabolism, inhibit fat cell differentiation, and enhance lipid breakdown, contributing to weight management and improved metabolic health.
Traditional basis: The respiratory application of yerba santa is the most historically consistent use across Indigenous, Spanish missionary, and early American pharmacological records. The plants are known for their medicinal properties and have been used by indigenous people for centuries to treat various ailments, in particular respiratory conditions.
Evidence: Yerba santa contains chemicals that might loosen mucus in the chest. The high 1,8-cineole content of the essential oil is consistent with known mechanisms of mucolysis and bronchodilation established for this terpene in other contexts. However, yerba santa has a long traditional history and interesting laboratory research behind it, but modern clinical evidence remains limited, especially for respiratory use. Clinical studies are limited, and yerba santa cannot be recommended for any indication based on current evidence.
Evidence strength: Primarily traditional and historical. No controlled clinical trials have been published specifically evaluating yerba santa for respiratory outcomes (bronchitis, asthma, cough, or expectoration) in humans. The evidence base for this application remains at the level of ethnobotanical record and mechanistic plausibility.
This is the most scientifically active area of yerba santa research. A Salk Institute discovery of a potent neuroprotective and anti-inflammatory chemical in a native California shrub may lead to a treatment for Alzheimer's disease based on a compound found in nature.
Key in vitro study (Fischer et al., 2019, Redox Biology): Analysis of one of the extracts from the plant yerba santa (Eriodictyon californicum) identified the flavanone sterubin as the active component. Surprisingly, only sterubin showed both potent neuroprotective activity against multiple insults as well as strong anti-inflammatory activity against several distinct inducers of inflammation when compared to closely related flavonoids. The study used HT22 hippocampal nerve cells and BV-2 microglial cells in multiple phenotypic assays related to aging and neurodegeneration.
In vivo study (Hofmann et al., 2020, Chemistry): Previous studies described the flavanone sterubin isolated from Eriodictyon californicum as a potent neuroprotectant in several in vitro assays. Hofmann et al. resolved synthetic racemic sterubin into its two enantiomers. Both (R)-sterubin and (S)-sterubin showed comparable neuroprotection in vitro with no significant differences. Sterubin was a potent neuroprotectant in vitro and displayed significant beneficial effects on short- and long-term memory in an AD mouse model.
Herbarium screening study (Maher et al., 2020, Frontiers in Pharmacology): Dichloromethane extracts were prepared from leaves of 14 Eriodictyon taxa preserved in the San Diego Natural History Museum herbarium. The extracts were tested for neuroprotection in nerve cells against oxytosis and ferroptosis and for anti-inflammatory activity in brain microglial cells exposed to bacterial lipopolysaccharide. In parallel, the levels of the flavanones sterubin, eriodictyol, and homoeriodictyol were measured by mass spectrometry. Several Eriodictyon species presented strong neuroprotective and anti-inflammatory activities. The protective properties of the extracts correlated with the amount of sterubin, but not with eriodictyol or homoeriodictyol, indicating that sterubin is the major active compound in these species.
Structural requirements study (PMC 2022): In order to understand which key chemical functional groups are essential to the beneficial effects of sterubin, researchers compared the activity of sterubin to that of seven closely related flavonoids in phenotypic screening assays. Surprisingly, only sterubin showed both potent neuroprotective activity against multiple insults as well as strong anti-inflammatory activity against several distinct inducers of inflammation.
Evidence strength: Compelling preclinical data (in vitro, animal models) but no human clinical trials have been published testing sterubin or yerba santa extract specifically for neurodegenerative outcomes. There are currently no ongoing clinical trials testing sterubin for dementia or age-related diseases, and no NIH-funded programs are currently investigating sterubin specifically. The evidence is promising but remains at the preclinical stage.
Randomized controlled trial (Mödinger et al., 2021, Journal of Medicinal Food): In a study evaluating effects of santa herba extract on body weight and appetite-related parameters in women who were overweight (BMI 25 to less than 30 kg/m²) or obese (BMI 30 to 35 kg/m²) (N=50), participants received either 400 mg of an E. californicum extract containing at least 4% homoeriodictyol (n=25) or placebo capsules (n=25) twice daily for 12 weeks with main meals. Data indicated that 12 weeks of supplementation led to an average 2.1 kg (4.6 lbs) decrease in body weight and a 0.4% reduction in body fat (related to total body composition) for the obese participants. While a nonsignificant trend toward body weight reduction was observed in the overall study population, statistically significant effects were observed in the obese subgroup.
The study assessed the impact of santa herba on oxidative stress, energy metabolism, weight reduction, and eating behavior, combining in vitro models with clinical data. Santa herba binding of the adenosine receptor A2A (ADORA2A) was assessed using a radioligand binding assay. A Caenorhabditis elegans model was used to determine mobility-boosting effects, and santa herba oxygen radical absorbance capacity (ORAC) values were determined in comparison to other antioxidative plants.
Evidence strength: One small, industry-sponsored RCT (N=50; all female; BMI-restricted). The body of research is still limited, with most evidence stemming from in vitro studies and animal trials rather than robust clinical studies. The optimal dosage for yerba santa has not been firmly established due to the limited number of clinical studies. This single RCT is insufficient to draw firm conclusions for the general population; replication by independent groups is needed.
At a concentration of 1.0 mg/mL, the ethanolic extract of E. californicum leaves showed 93.39% inhibition of DPPH radicals, 57.36% inhibition of superoxide radicals, and 80.89% inhibition of hydroxyl radicals; this study confirms that E. californicum leaves are a rich source of antioxidants and may be used as a nutraceutical. These findings are, however, from in vitro biochemical assays and do not directly translate to bioavailability or clinical outcomes in humans.
In sensory studies, flavanones homoeriodictyol, its sodium salt, sterubin, and eriodictyol could significantly decrease the bitter taste of caffeine without exhibiting intrinsic strong flavors or taste characteristics. Further investigations showed that homoeriodictyol sodium salt elicited a broad masking activity between 10 and 40% toward different chemical classes of bitter molecules (e.g., salicin, amarogentin, paracetamol, quinine) but not toward bitter linoleic acid emulsions. This application is well-characterized in sensory science and constitutes one of the strongest evidence-supported uses of yerba santa constituents, particularly homoeriodictyol sodium salt.
The leaves of Eriodictyon californicum contain different flavonoids which are known for their anti-inflammatory and anti-microbial activities against Gram-positive bacteria. This evidence is drawn from in vitro microbiological studies and has not been evaluated in human clinical trials.
Eriodictyon angustifolium extracts, but not E. californicum extracts, have been shown to reduce human hair graying. It has been proposed that an E. angustifolium extract, which is abundant in sterubin, may be suitable as a potential cosmetic and medical agent for the prevention and improvement of hair graying. It is unclear why E. californicum, which also contains sterubin, did not have a comparable effect, though the difference is possibly explained by the difference in quantity of the flavonoid.
Clinical data are lacking to provide dosing recommendations for yerba santa. The following dosages have been reported specifically in published studies:
There are no specific timing or absorption recommendations currently available, and further research is essential to determine safe upper limits and dosage guidelines.
There are no reports of significant adverse reactions associated with topical or systemic use of yerba santa. Contraindications have not been identified, and there are no reports of significant toxicity associated with topical or systemic use of yerba santa.
Yerba santa appears on the FDA's GRAS (Generally Recognized As Safe) list, a list of food additives recognized as safe by a consensus of scientific opinion. Many herbs are listed by the FDA because of their use in liqueurs and as components of natural flavorings prior to 1958, when the food additive regulations were written.
Avoid use during pregnancy and lactation; information regarding safety and efficacy in pregnancy and lactation is lacking.
Yerba santa is likely safe in food and medicinal amounts, but it may interact with lithium. This potential interaction is based on the diuretic properties attributed to the plant traditionally, which could theoretically reduce lithium excretion and increase serum lithium levels. No documented clinical case reports of this interaction have been published. No interactions are well documented.
Allergic contact dermatitis has been reported for the related species Eriodictyon parryi (poodle-dog bush). Cross-reactivity with E. californicum has not been formally studied, though sensitivity to one species in the genus may warrant caution with others.
Yerba santa is primarily used by herbal practitioners within the regions in which the species grow. Because the various species of Eriodictyon have been referred to as "yerba santa," including species that are threatened or endangered, it is important to fully characterize each species and develop basic standards for ensuring the identity, quality, and consistency of yerba santa raw material and finished products. Prior to recent investigation, a validated method for authenticating and distinguishing Eriodictyon species was lacking and no pharmacopoeia monograph standards had been established.
Though yerba santa has been used traditionally for thousands of years, it has not been the subject of many clinical studies, and data on its safety profile is relatively scarce. People use yerba santa for respiratory infections, fever, obesity, and many other conditions, but there is no good scientific evidence to support these uses. The available evidence base is dominated by in vitro and animal studies; the number of human clinical trials is very small, and those that exist (the 2021 weight management RCT) are limited in size and scope.
Condiciones de salud que Yerba santa puede ayudar a apoyar.
Yerba santa (Eriodictyon californicum) has traditional use among Indigenous California peoples and in 19th-century American botanical medicine as an expectorant, bronchospasmolytic, and bronchial tonic for coughs, bronchitis, and asthma. EBSCO's Natural Treatments for Bronchitis lists yerba santa among herbs with traditional support for bronchial conditions. Its active flavonoids including eriodictyol provide anti-inflammatory and expectorant effects.
Sistemas corporales que Yerba santa puede ayudar a apoyar.
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