IngredientsThe genus Ilex comprises over 570 species of flowering plants in the family Aquifoliaceae, and is the only living genus in that family. The species are evergreen or deciduous trees, shrubs, and climbers distributed from the tropics to temperate zones worldwide. When the term "holly" is used in the context of herbal medicine and dietary supplementation, it most commonly refers to three principal species:
These three species together carry an array of common names including American holly, Appalachian tea, Cassena, Christmas berry, Deer berry, English holly, Holly, Indian black drink, Indian holly, Oregon holly, and Yaupon. Additional species of medicinal interest to science include Ilex paraguariensis (yerba mate), Ilex cornuta (Chinese holly), Ilex rotunda, Ilex pubescens, and Ilex kudingcha, though these are considered distinct ethnobotanical subjects in their own right. The type species is Ilex aquifolium, the common European holly used in Christmas decorations and cards.
Ilex aquifolium is an evergreen shrub or small tree reaching up to 10β15 meters in ideal conditions. The glossy, spiny leaves β dark green and leathery β are arranged alternately, measuring 6β13 cm long with 3β5 pairs of spines. In mild climates, white to greenish-white flowers appear in clusters, followed by bright red drupes in winter. The species name aquifolium means "pointed leaf," and most of this evergreen shrub's leaves are spiny to deter grazers.
Ilex vomitoria (Yaupon holly) is an evergreen shrub or small tree reaching 5β9 m tall, with smooth, light gray bark and slender, hairy shoots. The leaves are alternate, ovate to elliptical with a rounded apex and crenate or coarsely serrated margin, 1β4.5 cm long and 1β2 cm broad, glossy dark green above, slightly paler below.
Ilex aquifolium is native to western and southern Europe, northwest Africa, and southwest Asia. It is renowned for its glossy, spiky leaves and bright red berries, which have made it a popular choice for holiday decorations. American Holly (Ilex opaca) originates from the eastern part of the United States, and it thrives in coastal and wetlands areas.
Only the leaves of certain species of holly are employed for medicinal use. Examples include Ilex vomitoria (Yaupon Holly) and Ilex aquifolium (European Holly). Ilex opaca is another kind of holly utilized for herbal supplementation, commonly called American Holly. The berries of all true holly species are toxic and not recommended for medicinal internal use (see Safety section).
Common forms and preparations include:
Holly has been known in Europe for centuries and was particularly valued in Celtic culture as a symbol of protection and eternal life. It was first documented in medicine in ancient times, where it was used to treat fever and rheumatism. Its role in folk medicine varied from region to region, and it was often used in rituals and to protect against evil spirits.
In Celtic culture, the holly tree was considered sacred and thought to possess protective qualities. It was used during rituals and celebrations, symbolizing life and rebirth. Holly was an important pagan plant of the winter season. Ivy represented the female, holly the male, at the rebirth of the year. Christians later welcomed holly as part of Christmas celebrations, finding symbolism in its pointy leaves and red berries.
The most traditional use of holly leaves in European folk medicine was as a diuretic and fever reducer (febrifuge). In British and European folk medicine, infusions made from dried holly leaves were consumed to promote urination (diuresis) and to reduce fevers associated with common infections and inflammatory conditions. The 17th-century English herbalist Nicholas Culpeper noted that the leaves "provoke urine" and were "good for the stone and gravel in the kidneys." Holly leaves were also used externally in poultices to treat joint pain and inflammation, particularly in cases suspected to be rheumatism or gout.
Holly is little used in modern herbalism. The leaves are diaphoretic, expectorant, febrifuge, and tonic. They can be used fresh at almost any time of the year or can be harvested in late spring and dried for later use. They are used in the treatment of intermittent fevers, rheumatism, catarrh, pleurisy, etc. The juice of the fresh leaves has been successfully used in the treatment of jaundice.
The berries are violently emetic and purgative. They have been used in the treatment of dropsy, and as a powder they have been used as an astringent to check bleeding. The berries are toxic, especially to children, and should not be used medicinally except under professional supervision. The root has been used as a diuretic, though more effective diuretics are available.
Maude Grieve, writing in 1931, lists several uses. According to her, "Holly leaves were formerly used as a diaphoretic and an infusion of them was given in catarrh, pleurisy and smallpox."
Holly bark was historically stripped, boiled, fermented, and pounded to make birdlime, a natural glue spread on the twigs of trees to trap birds for food.
A historical essay published in the early 19th century documented the advantages reaped from use of the leaves of the common holly (Ilex aquifolium) in the treatment of intermittent fever, noting "the unjust neglect which this indigenous shrub has experienced by its omission in the modern materiae medicae." The author proposed the holly as "a febrifuge and succedaneum for cinchona bark," indicating that holly leaves were investigated as a potential substitute for quinine-containing bark in the treatment of malarial fevers.
Yaupon holly is the only plant native to North America that contains caffeine. Archaeological evidence shows that Native Americans were using the yaupon holly to make a drink as early as 1,000 A.D. By the time Europeans made contact, the Indigenous peoples were using it to make a strong concoction known as the Black Drink, which was an important part of ceremonies.
For groups such as the Cherokee, Timucua, Choctaw, Muscogee, and Yugi, the Black Drink was an integral part of ceremonial life. Research suggests the Black Drink was used for special rituals including debates, religious engagements, and even in preparation for battle.
During the 16th and 17th centuries, European explorers and colonists documented the use of black drink by some southeastern indigenous cultures, including the local Timucua and Seminole chiefdoms. Black drink recipes varied from group to group, and may have included other species of holly or other herbal substances.
The various Native groups also used yaupon drinks outside of ritual ceremonial contexts. They drank it daily as a social drink, especially among men in council meetings. They also drank it as an energizing brew before combat or work. They used it as medicine to heal wounds, calm nerves, suppress appetite, and regulate menstrual cycles. They even used it to induce dreams.
Some Native American tribes, particularly in the Southeast, brewed the leaves and stems of Yaupon to make a ceremonial beverage known as the "black drink." These rituals often involved vomiting as a form of spiritual or physical purification β not because the plant itself was emetic. Early European observers misunderstood this practice and mistakenly concluded that Yaupon caused vomiting, hence the Latin name Ilex vomitoria. In reality, the active compounds in Yaupon β caffeine, theobromine, and theophylline β are the same as those found in its South American relatives, yerba mate and guayusa. Any vomiting likely resulted from the ceremonial context, which involved drinking large volumes while fasting, rather than from the plant's inherent properties.
There is strong evidence that I. vomitoria was transplanted and cultivated by Native American populations to create this drink. A second holly, Ilex cassine L. (known as Dahoon), might also have been used to prepare such drinks. Chemical analyses of organic residues in fragments of pottery from Cahokia and surrounding smaller sites in Illinois reveal theobromine, caffeine, and ursolic acid β biomarkers for Ilex vomitoria-based beverages, establishing use at major pre-Columbian Mississippian sites.
The Apalachee, Creek, Seminole, and Muskogee peoples referred to the beverage as the "white drink" because of its association with cultural practices related to peace and purity. Spanish colonists in the 16th century began calling this drink tΓ© del indio, or more commonly cacina or cassina (a word borrowed from the Timucua language). Later, English colonists began calling it the "black drink" because of the dark color produced when the leaves were brewed.
Use of Ilex vomitoria by colonists for tea-making and for medicinal uses in the Carolinas is documented by the early 18th century. During the Civil War, Southerners substituted yaupon holly tea for coffee and black tea.
The Chinese Pharmacopoeia (2025 edition) states that Ilex cornuta leaves are primarily used to treat liver and kidney-related conditions, with functions of clearing heat, nourishing yin, and alleviating symptoms such as hemoptysis caused by pulmonary tuberculosis, tidal fever with night sweats, and dizziness and vertigo. In folk medicine, the leaves of I. cornuta are used for treatment of several disorders, including weakness of the waist and knees, arthrodynia, headache, acute conjunctivitis, toothache, urticaria, rheumatic arthralgia, and cardiovascular diseases.
The genus Ilex has been utilized in traditional medicine and food for thousands of years, containing various bioactive compounds such as terpenoids, saponins, polyphenols, and glycosides.
In homeopathic practice, Ilex aquifolium is typically administered in low potencies. It is primarily indicated for conditions such as intermittent fevers, eye symptoms including corneal infiltration and staphyloma, and spleen pain. The homeopathic product marketed under this name is an unapproved homeopathic preparation; the FDA is not aware of scientific evidence to support homeopathy as effective.
Analyses of the leaves of I. aquifolium found tannic acid, a bitter glycoside (ilicin), ilexanthin (rutin), and ilicic acid. Some members of the genus, such as I. paraguayensis, contain xanthine alkaloids, such as caffeine, in levels as high as 2%.
Other species contain saponins and triterpenes. One review of the chemistry of Ilex documented hundreds of isolated compounds. Selected examples of the various classes of chemical constituents across the genus include: phenols and phenolic acids (p-hydroxybenzoic acid, arbutin), anthocyanins (pelargondin 3-bioside, cyanidin 3-glucoside), flavonols and flavones (rutin, kaempferol), terpenoids (alpha-amyrin, ursolic acid), sterols (sitosterol, ergosterol), purine alkaloids (caffeine, theobromine), amino acids (aspartic acid, glutamic acid), miscellaneous nitrogen compounds (trigonelline, choline), fatty acids (oleic, linolenic), alkanes and alcohols (nonacosane, mellisyl alcohol), and carbohydrates (sugar alcohols, sucrose).
Research on methanolic extracts from the fruits and leaves of Algerian Ilex aquifolium for enzyme inhibition studies identified chlorogenic acid, rosmarinic acid, hesperidin, and quercetin as predominant phenolic components by HPLC-DAD analysis.
The genus has been known for its numerous biological activities like antioxidant, antimicrobial, cytotoxic, anti-platelet aggregation, and anti-inflammatory effects. Most of the plants of this genus are rich sources of triterpenoids and saponins. Besides, these plants also contain flavonoids, alkaloids, anthocyanins, and other phenolics in minor quantities.
The plant contains ilicin (a bitter principle), ilexanthin, ilicic acid, theobromine, caffeine, and caffeic acid. Ilexanthin, also known as syringin, was first isolated from the bark of lilac (Syringa vulgaris). It contains a glucose group attached to a sinapyl alcohol; when taken orally, sinapyl alcohol β which has anti-inflammatory properties and is antinociceptive (i.e., reduces sensitivity to pain) β is formed. Ilicic acid is phytotoxic, meaning it is toxic to plants and may be present to deter competitors from growing nearby.
Ilex aquifolium contains a distinctive blend of bioactives, particularly triterpene saponins. Triterpenoids found in English holly have anti-inflammatory properties and may contribute to the plant's traditional use in treating various ailments. Saponins found in English Holly have potential cardiovascular benefits and may help lower cholesterol levels.
The European species Ilex aquifolium shows similarities in its terpenoid, sugar, and phenolic acid profiles to the more studied South American species.
Ilex vomitoria leaves contain active ingredients such as caffeine, theobromine, ursolic acid, and theophylline, just like the related yerba mate and guayusa hollies. Three species of Ilex were subjected to tests for caffeine. Results were obtained for Ilex paraguariensis (4.15β11.86 mg/g), Amazonian Ilex guayusa (19.11β26.94 mg/g), and Ilex vomitoria (0.004β8.44 mg/g). The alkaloid theobromine is also found in cocoa, tea, and cola and is used to treat asthma.
Tannins are astringent compounds found in the leaves and bark of the plant. They have been used historically for their antiseptic properties.
Holly contains a variety of potentially injurious substances within the leaves and berries, including saponins, triterpenes, polyphenols, methylxanthines, and cyanogens.
Important note on evidence quality: The overwhelming majority of scientific research on Ilex aquifolium specifically β as opposed to the genus Ilex broadly β consists of in vitro (cell culture) studies and animal models. As of the time of writing, no robust controlled human clinical trials have been conducted specifically on I. aquifolium leaf preparations. Evidence described below must be understood in that context.
The European species Ilex aquifolium shows similarities in its terpenoid, sugar, and phenolic acid profiles to I. paraguariensis. Using aqueous extracts of Ilex aquifolium as a supplement in Wistar rats showed that, despite the lack of caffeine, it had strong hypocholesterolemic effects. In addition, a reduction in oxidative lipid degradation and a decrease in hepatic steatosis in histopathological studies were observed. The results of this study suggest that extracts from the European species Ilex aquifolium may have potential as an alternative treatment for hyperlipidemia.
This evidence is limited to a preclinical animal (rat) model. No human clinical trial data on I. aquifolium and lipid levels has been identified in the peer-reviewed literature to date.
A 2024 study published in PMC evaluated chemical profiling of I. aquifolium Silver Queen, chosen as the source of terpenoid and saponin fractions and polyphenol extracts. The most substantial inhibition of cancer cell growth was observed with saponin in the case of the MCF7 (human breast cancer) cell line, while for LoVo and L929 cell lines (human colorectal cancer and reference mouse fibroblasts), it was slightly weaker. The authors noted that these results should be analyzed further as a promising chemoprevention strategy. Saponin and polyphenolic extracts exhibited similar activities against HSV-1 and HAdV-5, with a 4-log reduction in virus titres. This study focuses attention on the field of potential antiviral formulations derived from European holly.
These results are in vitro only and do not constitute clinical evidence of antiviral efficacy in humans.
Studies on Algerian Ilex aquifolium found that leaf extracts possessed moderate antibacterial and antifungal activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacter aerogenes, Proteus vulgaris, Salmonella typhimurium, and Candida albicans, with activity varying from 62.5 Β΅g/mL. A significant amount of hydroxycinnamic acid esters of quinic acid in Ilex species, as well as reported antimicrobial activity of I. paraguariensis water extract and antibiofilm properties of I. guayusa, make holly species candidates for antibacterial research.
All current evidence is from in vitro studies. No human clinical data exist for this indication.
Flavonoids are antioxidants found in Ilex aquifolium that play a role in reducing oxidative stress in the body. Research on Ilex species broadly has explored antioxidant activity through DPPH, ABTS, CUPRAC, and FRAP assays, with identification of chlorogenic acid, rosmarinic acid, hesperidin, and quercetin as predominant phenolic components. Studies using aqueous extracts of Ilex aquifolium as a supplement in Wistar rats also observed a reduction in oxidative lipid degradation. This is preclinical data only; human data are lacking.
In a study on the holly species Ilex rotunda, isolated phenolic compounds exhibited significantly high antioxidative effects in both free radical scavenging and ROS assays. These isolates also markedly altered interleukin (IL)-2 production in CD3/CD28-stimulated Jurkat T cells. Western blotting assays suggested that these active compounds might decrease IL-2 production by blocking the activation of NF-ΞΊB and MAPK signaling pathways by downregulating the phosphorylation of p38 and p65 proteins as well as ERK and JNK kinases.
Research on Ilex terpenoid fractions found that they inhibit the production of pro-inflammatory cytokines such as IL-2, IL-3, and TNF-Ξ±. These mechanisms have been demonstrated in cell-based and animal studies; human clinical evidence is absent for I. aquifolium specifically.
The most substantial inhibition of cancer cell growth in I. aquifolium Silver Queen extracts was observed with saponin fractions in the case of the MCF7 (human breast cancer) cell line, while for LoVo and L929 cell lines (human colorectal cancer and reference mouse fibroblasts), it was slightly weaker. The researchers noted these results should be analyzed further as a promising chemoprevention strategy for colorectal and gastrointestinal cancers.
Many of the Ilex species are known for their contributions in anticancer, antinociceptive, and anti-inflammatory effects according to preclinical data. However, all such findings remain at the laboratory (in vitro) stage and have not been evaluated in human clinical trials.
The active compounds in yaupon β caffeine, theobromine, and theophylline β are the same as those found in its South American relatives, yerba mate and guayusa. Native Americans carried dried yaupon leaves with them to make a caffeine-loaded tea that made them less susceptible to thirst, hunger, and exhaustion. The stimulant properties attributed to I. vomitoria are pharmacologically plausible given its methylxanthine content, which is well-characterized in the literature, but modern controlled clinical studies specifically on this species as a supplement have not been identified in peer-reviewed sources.
Holly has been traditionally used to reduce fever by promoting sweating, contributing to the body's natural cooling mechanisms during illnesses. The 19th-century clinical observations of holly as a "succedaneum for cinchona bark" in intermittent fevers (proposing holly as "a febrifuge and succedaneum for cinchona bark") represent historical case-based claims rather than controlled clinical evidence. No modern randomized controlled trials on this application have been identified.
There are no standardized, regulatory-approved dosages for Ilex aquifolium leaf preparations in human supplementation. Reported doses in the literature are largely from traditional use descriptions and animal studies, not from human clinical trials.
Holly exposure accounts for the 3rd highest rate of genus-specific human plant exposure calls in the United States (877 calls in 2010). The berries containing the toxin saponin are poisonous; the leaves are not. The primary potential biological effect of saponin is a negative interaction with cellular membranes.
Berries contain the saponin ilicin, which is a potent gastrointestinal irritant. In humans and companion mammalian species, the most common sign is upset of the digestive tract. No antidote exists, and treatment is symptomatic.
The ingestion of fruits, because of their content in ilicin, is very poisonous for the digestive tract and can produce very irritating effects in the stomach or intestines. Their principles can attack the nervous system and heart. Their high content in resins can produce intestinal obstructions. Symptoms include vomiting, swallowing difficulty, blurred vision, irregular heartbeat, respiratory difficulty, convulsions, and in more extreme cases, death.
Ethanol leaf extracts of holly were lethal when injected into mice, but fruit extracts caused no toxic effects in mice by the same route. The primary toxic effects of holly ingestion are owing to gastrointestinal irritation from the saponins. Ingestion of holly in small animals generally causes no more than mild to moderate gastrointestinal upset.
English and American holly should not be confused with South American Ilex species (I. paraguariensis and I. guayusa), which are commonly used to make teas and other drinks for their reported antioxidant properties and caffeine content. The berries containing the toxin saponin are poisonous; the toxic component of the berries is saponin, whose primary potential biological effect is a negative interaction with cellular membranes.
Holly's potentially injurious substances are present within both the leaves and berries, and include saponins, triterpenes, polyphenols, methylxanthines, and cyanogens. However, the latter two substances do not appear to contribute significantly to toxicity when holly is ingested by animals.
English Holly (Ilex aquifolium) is the most common variety associated with highly decorative, intensely red berries and sharply spined leaves, particularly during the Christmas season. Its berries contain high levels of saponins and are considered highly toxic if ingested in quantity. Winterberry Holly (Ilex verticillata), while often considered less toxic than English Holly, produces bright, persistent berries that are highly appealing.
Holly is little used in modern herbalism. The leaves of many holly species are traditionally used as emetics or laxatives, indicating dose-dependent purgative risk even with leaf preparations. The berries are toxic and not recommended for internal use.
Further investigation in terms of isolation of bioactive compounds and their toxicological evaluations are needed to validate observed pharmacological results. The gap between in vitro activity and confirmed human safety profiles for leaf extracts remains wide and unresolved in the published literature.
Holly in homeopathic preparations is classified as an unapproved homeopathic product. The FDA is not aware of scientific evidence to support homeopathy as effective.
Health conditions that Holly may help support.
A peer-reviewed in vitro study confirmed that I. aquifolium ethanolic extract inhibits non-enzymatic lipid peroxidation and scavenges hydroxyl radicals, with phenolic constituents (hyperoside, rutoside, chlorogenic acid) identified as responsible agents. Additional phytochemical analyses confirm high phenolic and flavonoid content with measurable antioxidant activity.
A preclinical study using obese Zucker rats showed that I. aquifolium saponin and terpenoid fractions reduced total cholesterol, LDL, and liver adiposity, and improved insulin sensitivity. Evidence is limited to animal models with no human clinical trials.
Ethanolic extract of I. aquifolium has been shown in vitro to inhibit leukotriene B4 biosynthesis in isolated bovine polymorphonuclear leukocytes (PMNL), indicating anti-inflammatory potential at a biochemical level. The genus Ilex is broadly recognized for anti-inflammatory activity. Evidence remains preclinical.
Joint pain and rheumatism are among the most consistently documented traditional indications for I. aquifolium leaves, both internally as infusions and externally as poultices. The anti-inflammatory triterpenoids present in the plant provide a plausible mechanism, though human clinical evidence is absent.
Reduction of high blood pressure is listed among the traditional medicinal uses of I. aquifolium leaves in multiple folk medicine sources. Other Ilex species with better-studied evidence support cardiovascular/blood pressure effects, providing biological plausibility. No human clinical trials exist for I. aquifolium.
Holly leaves have a documented tradition in European herbalism as an expectorant and for treating catarrh (mucous membrane inflammation of the airways) and chest congestion. The plant contains trace methylxanthines (theobromine, theophylline) that may provide mild bronchodilatory effects.
Holly leaf (Ilex aquifolium) has a long-documented history in European folk medicine as a febrifuge. Leaves were classified as diaphoretic and febrifuge in traditional herbal texts, and infusions were consumed to reduce intermittent fevers. No clinical trials have confirmed this use in humans.
Holly leaves and roots are documented in European traditional medicine as diuretics specifically employed for gout and dropsy, conditions associated with fluid accumulation and uric acid excess. No clinical evidence supports this use.
The juice of fresh I. aquifolium leaves has a documented traditional use for treating jaundice, suggesting a historical association between holly and liver function. The 2022 preclinical study also found reduced liver adiposity with I. aquifolium fractions.
Pleurisy is explicitly listed among the conditions treated with I. aquifolium leaf preparations in multiple traditional European herbalism sources. This use is consistent with the plant's broader role as an expectorant and anti-inflammatory herb in folk medicine.
Holly leaf preparations are documented in the traditional European herbalism as a treatment for respiratory illnesses broadly, including conditions associated with throat irritation and catarrh. The astringent tannin content may provide a rationale for topical use.
Holly leaves and roots have a well-documented traditional use as a diuretic across European herbal medicine. Infusions and decoctions of leaves were used to treat dropsy (edema), rheumatism, and gout through promotion of urination. No clinical evidence is available.
Holly leaves have a documented history of topical use in poultices for wounds and skin conditions in European folk medicine. The astringent tannin content and documented antimicrobial activity of I. aquifolium extracts provide partial biological plausibility.
Body systems that Holly may help support.
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