Botanical name Hyssopus officinalis L
Source Leaves and Flowers
Processing Method Steam Distillation
Color/Consistency A thin, pale yellow to yellow liquid.
Aromatic Summary / Note / Strength of Aroma A top note with a medium aroma, Hyssop Essential Oil has a sweetly medicinal scent that many find appealing.
Blends With Eucalyptus, Ravensara, Niaouli, Cajeput and Myrtle.
Hyssop, both flowers and leaves, has been highly valued since ancient times for its therapeutic properties, and was one of the bitter herbs mentioned in the Old Testament (used in the Passover ritual). Hippocrates, Galen and Dioscorides favoured its bechic and pectoral properties. In pagan religious ceremonies, hyssop was sprayed on worshippers to purify them. The Romans used it medicinally and culinarily, the latter both for protection against plague and for its aphrodisiac effect in conjunction with ginger,thyme and pepper. Thomas Tusser in 500 Points of Good Husbandry (1573) recommended hyssop as a strewing herb, and by the time of the great herbals of the Middle Ages, the herb was so well known that their writers felt no need to go into too much detail about it.
It has a hairy, woody stem, small lance-shaped green leaves and purple-blue flowers. Well used in ancient times, Hyssop was referred to in the Bible for its cleansing effect in connection with disease. It was used for purifying sacred places and during the Middle Ages, as a strewing herb to ward off lice.
Under optimal weather conditions, herb hyssop is harvested twice yearly, once at the end of spring and once more at the beginning of the fall. The plants are preferably harvested when flowering in order to collect the flowering tips.
Due to the presence of pinocamphon in this oil, please consult a physician prior to use. Dilute before use; for external use only. May cause skin irritation in some individuals; a skin test is recommended prior to use. Contact with eyes should be avoided.
Myrtenyl methyl ether 0–3.9%
Hazards Neurotoxicity; may contain the carcinogen methyleugenol.
Contraindications (all routes) Pregnancy, breastfeeding, children under 2 years of age.
Contraindications Should not be taken in oral doses.
Maximum dermal use level
Tisserand & Young 0.3%
Our safety advice
We recommend a dermal maximum of 0.3%, based on 82.3% total pinocamphone, isopinocamphone and thujone content, with a dermal limit of 0.25%.
IFRA recommends that the maximum concentration of methyleugenol for leave-on products such as body lotion should be 0.0004% (IFRA 2009). The equivalent SCCNFP maximum is 0.0002%.
Adverse skin reactions Undiluted hyssop oil (pinocamphone CT) was not irritating to rabbit, pig or mouse skin; tested at 4% on 25 volunteers it was neither irritating nor sensitizing. It is non-phototoxic.
Neurotoxicity The amounts of hyssop oil used in the animal tests (see below) were generally high. However, there are three reported cases of low-dose hyssop oil ingestion resulting in epileptiform convulsions. The first case was a 6-year-old whose mother frequently gave him 2–3 drops of hyssop oil for his asthma. During one severe attack, he was given ‘half a coffee spoon’ (15–20 drops?) shortly after which he suffered a convulsion. He fully recovered after three days in hospital. The second case, an 18-year-old girl, drank 30 drops of hyssop oil to treat a cold. One hour later she lost consciousness for 10 minutes, during which she suffered generalized contractions and bit her tongue. In the third case a 26-year-old woman took 10 drops of hyssop oil on each of two consecutive days, and suffered a seizure on the second day.
Acute toxicity Hyssop oil acute oral LD50 in mice 1.4 mL/kg; acute dermal LD50 in rabbits 5 mL/kg. Intraperitoneal pinocamphone was convulsant and lethal to rats above 0.05 mL/kg and convulsions appeared for hyssop oil at doses over 130 mg/kg.
Carcinogenic/anticarcinogenic potential A hyssop oil with 0.67% methyleugenol was not mutagenic
in S. typhimurium strains T98 and T100, with or without metabolic activation. Methyleugenol is a rodent carcinogen if exposure is sufficiently high.
This chemotype is so common it is normally referred to simply as ‘hyssop oil’. Hyssop oil should be regarded as hazardous oil because of its potential to cause convulsions, especially if taken orally.