Juniper

Information
Application
Notes
References

Photo: Sertürner Bildarchiv

Botanical name

Juniperus communis. L.

Family

Cupressaceae

Common name

Common juniper

Information about the plant

Only two of the approximately 60 juniper species are native to Central Europe: the common juniper (Juniperus communis) and the savin juniper (J. sabina). The needles of the J. sabina tree have an unpleasant odor, which is why it is also known as the stinking juniper. Its essential oil was once used to treat menstrual disorders and was also abusively used for abortion. J. communis, the common juniper (Latin ‘communis’ = common), is highly variable in growth habit, as well as needle shape and length. It exists in three subspecies in Europe and is also cultivated in various garden forms.

The common juniper typically grows as a columnar shrub or tree on heathlands, in sparse coniferous forests, and on rough pastures. The needle-like, prickly leaves, up to 20 mm long, are arranged in whorls of three along the twigs and have a clear blue-white waxy stripe on the upper side. The female flowers stand upright, surrounded by several 3-membered whorls of pointed scale leaves, with the three apical ones concavely curved. Although the juniper is a gymnosperm (the ovules are exposed and not surrounded by carpels), it produces berries. Botanically, these are actually ‘pseudo-berries’ because, after pollination, it is not the carpels (which are absent) but the three uppermost scale leaves that grow fleshy, like a fruit around the ovules and enclose them (botanically: berry cones). When ripe, the ‘juniper berries’ are black, with a bluish tinge, spherical to ovoid, with light brown seeds.

Medicinally used parts of plants (herbal drug)

The ripe berry cones (juniper berries - Juniperi pseudofructus) are used. When crushed, they release their typical juniper aroma due to the essential oil contained in the berries. This oil is extracted from the ripe berry cones by steam distillation and is also used medicinally (juniper oil - Juniperi aetheroleum).

The commercially available drug comes from Croatia, Italy, and Albania.

In the past, juniper wood was also used in traditional medicine, but this is now obsolete.

Constituents of the herbal drug

Juniper fruits contain 0.8 to 2% essential oil with monoterpene hydrocarbons as the main components, inverted sugar, catechin tannins, leucoanthocyanins, and diterpenes.

Quality of the drug

The quality of the following drugs or drug preparations is specified in the European Pharmacopoeia (Ph. Eur.):

Juniper berries (Juniperi pseudofructus)
Juniper oil (Juniperi aetheroleum)

Medical applications

Recognised medical use

The HMPC has classified juniper berries and juniper oil as traditional herbal medicinal products (see ‘Traditional use’).

ESCOP: Juniper berries: to improve renal water excretion and for dyspeptic complaints.

Traditional use

Juniper berries and juniper oil have been classified by the HMPC as traditional herbal medicinal products (Article 16a of Directive 2001/83/EC). Based upon long-standing use, juniper berries and juniper oil can be taken internally to flush the urinary tract as a supportive treatment for minor urinary tract complaints, as well as for dyspeptic complaints and flatulence. Juniper oil is also used externally for mild muscle and joint pain, based upon long-standing use.

Herbal drug preparations in finished dosage forms

Juniper berries for chewing
Crushed juniper berries for tea preparation
Juniper oil in enteric-coated capsules for ingestion
Juniper oil in liniments
Juniperus communis siccatus homeopathic mother tincture in liquid preparations

Dosage

Finished medicinal product: See patient information leaflet.

Juniper berries for flushing the urinary tract: Starting with 5 berries per day, the dose can be increased by 1 berry per day up to 15 berries per day. Then reduce the dose down to 5 berries per day.

Tea: Drink a cup of juniper berry tea 2 to 3 times per day. Average daily dose: 4 to 6 g of the drug.

Juniper oil: Internally, daily dose of 60 to 100 mg, taken 3 times a day. Externally, as a bath additive 1 to 1.5 g per full bath, 3 to 4 times a week.

Preparation of a tea

Pour 150ml of boiling water over 2g of freshly crushed juniper berries and strain after 10 minutes.

Notes

If juniper berries or juniper oil are used for flushing therapy, ensure adequate fluid intake.

Juniper berries must not be taken in the case of kidney disease. In case of fever, urinary retention, cramps during urination, or blood in the urine occur during treatment, medical advice should be sought. A combination with synthetic diuretics is not recommended.

No safety studies are available on the use of juniper berries or juniper oil during pregnancy and lactation. The use of juniper berries in children and adolescents under the age of 18 is not recommended due to a lack of evidence.<

Side effects

Allergic skin reactions can occasionally occur with external application. In case of overdose, the urine develops a violet-like odor, accompanied by pain in the kidney-bladder region.