Medically reviewed on June 7, 2018
What is Parsley?
Parsley is an annual herb indigenous to the Mediterranean region, but now cultivated worldwide. It has erect stems and bright green leaves. Two cultivars of parsley exist: a curly leaf type and a flat leaf type. Parsley produces an umbel of tiny flowers and characteristic ribbed seeds.
Caution must be used when gathering wild parsley because of the general similarity of its leaves and flowers to 3 common poisonous plants. The first, Aethusa cynapium (dog poison, fool's parsley, small hemlock) may be distinguished from parsley by the shiny, yellow-green underside of the leaves, which are dull in parsley, and the white flowers, which are yellowish in parsley. Similarly, collectors should be aware of Conium maculatum (poison hemlock, water hemlock, poison parsley) and Cicuta maculata (water hemlock). Poison hemlock is a much larger plant than common parsley. Poisonings have occurred when the leaves of Conium were mistaken for parsley and the seeds for anise. Symptoms of Conium and Cicuta poisoning include vomiting, diarrhea, weakness, paralysis, weak pulse, dilated pupils, convulsions, and death.
Parsley also is known as rock parsley and garden parsley.
What is it used for?
Parsley leaves and roots are popular as condiments and garnish worldwide. In Lebanon, parsley is a major ingredient in the national dish tabbouleh. An average adult may consume as much as 50 g of parsley per meal.
Parsley has been used as a source of certain vitamins and minerals. Parsley seed was used traditionally as a carminative to decrease flatulence and colic pain. The root was used as a diuretic and the juice to treat kidney ailments. Parsley oil also has been used to regulate menstrual flow in the treatment of amenorrhea and dysmenorrhea, and is purported to be an abortive. Bruised leaves have been used to treat tumors, insect bites, lice, skin parasites, and contusions. At one time, parsley tea was used to treat dysentery and gallstones. Other reported traditional uses include treatment of diseases of the prostate, liver, and spleen. Historically, parsley also has been used in the treatment of anemia, arthritis, and cancers, as an expectorant, antimicrobial, aphrodisiac, hypotensive, diuretic, and laxative. It also has been used as a scalp lotion to stimulate hair growth. However, there have been no clinical trials to confirm these uses.
What is the recommended dosage?
Parsley has been used at daily doses of 6 g. However, no clinical studies have been found that support this dose. The essential oil should not be used because of toxicity.
Contraindications have not yet been identified.
Generally recognized as safe when used as food. Safety and efficacy for dosages above those in foods are unproven and should be avoided. Emmenagogue (to stimulate menstrual flow) and abortive effects in higher doses.
None well documented.
Adverse effects from the ingestion of parsley oil include headache, giddiness, loss of balance, convulsions, and renal damage. The psoralen compounds found in parsley have been linked to a photodermatitis reaction found among parsley cutters.
While no major toxicities have been reported with the use of parsley, pregnant women should not take parsley because of possible uterotonic effects.