Juniper is an evergreen tree found in India, southwest Asia, Europe, and North America (
12230,
94060). The berries, aerial parts, and bark are all used for various medicinal purposes (
94060). There are many varieties of juniper, but Juniperus communis is the most common in North America (
12230).
LIKELY SAFE ...when used orally in amounts commonly found in foods. Juniper, juniper berry, and juniper extract have Generally Recognized as Safe (GRAS) status in the US (
4912).
POSSIBLY SAFE ...when used topically on limited areas of skin (
12230). ...when the oil is used by inhalation and appropriately as aromatherapy (
7107).
There is insufficient reliable information available about the safety of juniper when used orally in doses of less than 10 grams of berries or 100 mg of oil daily, short-term. Juniper oil and berry have a long history of traditional use (
12,
103759).
LIKELY UNSAFE ...when used orally in excessive amounts or long-term. Use of daily doses greater than 10 grams of juniper berries (about 60 berries) or 100 mg of juniper essential oil, or prolonged oral use longer than 4 weeks, have been reported to increase the risk of severe adverse effects such as convulsions or kidney damage (
8,
19,
103759).
PREGNANCY:
UNSAFE ...when used orally. Juniper can increase uterine tone, interfere with fertility and implantation, and cause abortion (
4,
19).
LACTATION: Insufficient reliable information available; avoid using.
General: Orally and topically, juniper seems to be generally well tolerated when used short-term in low doses. However, a thorough evaluation of safety outcomes has not been conducted.
Most Common Adverse Effects:
Topically: Allergies, skin irritation.
-
Topically, juniper can cause skin irritation. Signs of topical poisoning include burning, erythema, inflammation with blisters, and edema (
4). Repeated exposure to the juniper pollen can cause occupational allergies that affect the skin (
6). In a case report, a 62-year-old woman developed burn-like blistering lesions after carrying juniper in close contact to her skin. Concurrent sun exposure was thought to worsen the skin irritation caused by juniper (
103756).
-
Orally, large amounts of the juniper berry can cause purplish urine (
4).
-
Repeated exposure to the juniper pollen can cause occupational allergies that affect the respiratory tract (
6).
INSUFFICIENT RELIABLE EVIDENCE to RATEBronchitis. Although there has been interest in using inhaled juniper essential oil for bronchitis, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Cancer. Although there has been interest in using oral juniper for cancer, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Diabetes. Although there has been interest in using oral juniper for diabetes, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Dyspepsia. Although there has been interest in using oral juniper for dyspepsia, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Flatulence. Although there has been interest in using oral juniper for flatulence, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Gastroesophageal reflux disease (GERD). Although there has been interest in using oral juniper for GERD, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Kidney stones (nephrolithiasis). Although there has been interest in using oral juniper for nephrolithiasis, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Intestinal parasite infection. Although there has been interest in using oral juniper for intestinal parasite infection, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Rheumatoid arthritis (RA). Although there has been interest in using topical juniper for RA, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Urinary tract infections (UTIs). Although there has been interest in using oral juniper for UTIs, there is insufficient reliable information about the clinical effects of juniper for this purpose.
Wound healing. Although there has been interest in using topical juniper for wound healing, there is insufficient reliable information about the clinical effects of juniper for this purpose.
More evidence is needed to rate juniper for these uses.
HERBS AND SUPPLEMENTS WITH HYPOGLYCEMIC POTENTIAL: Theoretically, taking juniper berry with herbs and supplements with hypoglycemic potential might cause additive hypoglycemia.
Details
Animal research shows that juniper berry can lower blood glucose (
4,
10580,
14907). See other products with hypoglycemic potential
here.
Theoretically, juniper berry might exacerbate certain gastrointestinal conditions. Juniper berry might irritate the gastrointestinal tract (
19).
Theoretically, juniper berry might interfere with blood pressure control. Juniper berry might have effects on blood pressure (
4,
512).
Theoretically, juniper might interfere with blood glucose control during and after surgical procedures. Animal research shows that juniper berry can lower blood glucose (
4,
10580,
14907). Tell patients to discontinue juniper at least 2 weeks before elective surgical procedures.
There is insufficient reliable information available about the presentation or treatment of overdose with juniper.
There is insufficient reliable information available about the pharmacokinetics of juniper.
General: Juniper berries and leaves contain flavonoids including apigenin, rutin, and luteolin (
12230,
57203,
57215,
94060). Juniper berry oil is mostly composed of monoterpenes including alpha-pinene (51.4%), myrcene (8.3%), sabinene (5.8%), limonene (5.1%), and beta-pinene (5.0%) (
94060). The seeds and fruit also contain glycolic acid, formic acid, malic acid, acetic acid, ascorbic acid, and camphor (
94060). Various extracts of juniper made from dried stems showed differing amounts of constituents including flavonoids, volatile oil, and coumarins (
94060). Juniper extracts also contain flavonoids, tannins, alkaloids, diterpenes, sesquiterpenes, and neolignan glycosides (
12230,
57208,
94060).
Abortifacient effects: Abortions have been induced in cattle fed juniper (
57211). Isocrupressic acid has been identified as an active abortifacient compound in juniper.
Analgesic effects: Juniper seems to have some antinociceptive activity and likely acts both peripherally and centrally. In animal research, a methanolic extract of juniper exhibited a dose dependent effect on the writhing response (
94060). Additionally, in mice, intravenous administration of a lyophilized aqueous extract of juniper produced an analgesic response of 178% as measured by thermal stimuli (
57219).
Antibacterial effects: Juniper berry has demonstrated antibacterial effects in vitro (
4,
10939,
103755). Juniper berries showed activity against Escerichia coli, Staphylococcus aureus, and Hafnia alvei. A hexane extract of juniper leaf appears to have more antibacterial activity compared to ethanol, methanol, and chloroform extracts (
94060). Volatile oils of Juniperus communis have higher activity against S. aureus when compared with other juniper species (
103755).
Antidiabetic effects: In animals, juniper berry seems to reduce blood glucose levels and decrease polydipsia. It appears to work primarily by increasing peripheral glucose uptake (
10580,
14907,
94060).
Antifungal effects: Juniper berry oil has demonstrated antifungal effects in vitro (
4,
10939).Oil from the aerial parts of juniper has shown some activity against Rhizoctonia solani and Rhizopus stolonifer. This activity is thought to be due to the monoterpenes found in juniper (
94060).
Anti-inflammatory effects: Juniper fruit has demonstrated inhibition of prostaglandin and platelet activating factor exocytosis in vitro (
94060). Oral administration of an ethanolic extract of juniper reduced carrageenan-induced rat paw edema by 60% compared to 45% for indomethacin (
13466).
Antimalarial effects: Essential oil from juniper has shown some activity against Plasmodium falciparum in vitro (
94060).
Antioxidant effects: In vitro research shows that juniper can block the oxidation process and increase the activity of antioxidant enzymes (
94060).
Cardiac effects: Intravenous administration of a lyophilized aqueous extract of juniper, 25 mg/kg body weight, to normotensive rats produced an initial transient rise in arterial pressure followed by a reduction of 27% (
57219). The mechanism of these effects is unclear.
Diuretic effects: The diuretic action of juniper has been attributed to terpinen-4-ol (
57207). However, some animal research suggests that the diuretic effect is partly due to the essential oil and partly to hydrophilic constituents (
57218). The magnitude of juniper's diuretic effects is unclear, as some animal research shows that aqueous juniper extract is no more effective than water at increasing urine volume while other animal research shows significant effects only at higher concentrations (
57218,
57219).
Hepatoprotective effects: Juniper has demonstrated hepatoprotective effects in animal research. Compared with rats receiving placebo, rats receiving juniper and then exposed to CCl4 had less pronounced increases in serum SGPT, SGOT, ALP, and bilirubin. Ethanol and aqueous extracts of juniper may be more effective (
94060). The mechanism of these effects is unclear.
Lipid effects: Animal research shows that juniper methanolic extract and oil can increase high-density lipoprotein (HDL) cholesterol and decrease low-density lipoprotein (LDL) cholesterol, respectively, in diabetic rats (
94060). The mechanism of these effects is unclear.
Neurologic effects: A methanolic extract of juniper has been shown to reduce reserpine induced catalepsy compared with reserpine alone in rats. (
94060). Juniper has also shown some neuroprotective activity in a chlorpromazine induced Parkinson's model in rats (
94060). The mechanism of these effects is unclear.
Monographs are reviewed on a regular schedule. See our
for details. The literature evaluated in this monograph is current through 10/3/2024. This monograph was last modified on 7/26/2024. If you have comments or suggestions, please