Parsley gets its Latin name, Petroselinum, from the Greek for “rock celery.” A tablespoon (3.8 g) of the fresh leaves has 1 calorie, yet it holds 62.3 µg of vitamin K, 52% of the daily value. Two tablespoons cover a whole day, which is why parsley matters to people who take warfarin.
Parsley is also unusual for the flavone apigenin. A tablespoon has 8.19 mg, against 1.14 mg in a whole celery stalk in the USDA data used on this site. In the plant, apigenin is bound to sugars as a compound called apiin. In people, only a small part of it reaches the blood.
Parsley is a garnish in most kitchens, but not in tabbouleh. Traditional Levantine versions use more parsley than bulgur. Human research on parsley is thin: the 7 trials below fed groups of 3 to 85 people for days to weeks, and a 2024 review found a big lack of clinical evidence.
Health benefits of parsley
The top findings from 14 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★Higher antioxidant enzyme activity in red blood cellsA week of parsley on a controlled diet raised two antioxidant enzymes in red blood cells in 14 adults. It measured blood markers, not illness.
- ★No change in blood clottingEating 5 g of dried parsley a day for 7 days did not change blood clotting or platelet measures in 18 healthy people.
- ★Absorption of parsley apigenin depends on the formAfter a very large serving of blanched parsley, only 0.22% of the apigenin appeared in urine. Another trial measured breakdown products differently: 11.2% of the amount eaten from a parsley drink, 0.5% from pure apigenin.
- ★No change in urine or stone-risk markersDrinking 1,200 mL of parsley leaf tea a day for 2 weeks did not change urine volume or stone-risk markers in 20 healthy people. It says little about stone prevention.
- ★Lower weight and blood fats, reversing afterwardsIn 85 obese women, 4 weeks of a low-calorie diet with parsley seed bread (seeds, not leaves) lowered weight and blood fats. There was no comparison group, so the diet may explain part of this, and values rose again afterwards.
All 14 studies, strongest evidence first
A week of parsley on a controlled diet raised two antioxidant enzymes in red blood cells in 14 adults
Randomized crossover trial in 7 men and 7 women. For 2 weeks they ate a diet low in flavones, with parsley added in one week, supplying 3.73 to 4.49 mg of apigenin per megajoule of energy. Glutathione reductase and superoxide dismutase rose, while catalase and glutathione peroxidase did not change. About 0.58% of the apigenin came out in urine. Enzyme activity drifted down over the 2 weeks, and parsley only partly offset that. It measured blood markers, not illness.
Eating 5 g of dried parsley a day did not change blood clotting or platelet measures in healthy people
Randomized crossover study in 18 healthy volunteers who ate 220 g of onions, 5 g of dried parsley providing 84 mg of apigenin, or a placebo, for 7 days each. Neither parsley nor onions changed platelet clumping, thromboxane B2, factor VII or other clotting measures, and the authors could not measure apigenin in the blood. The lab part of the paper found that only very high flavonoid levels slowed platelet clumping.
After a very large serving of blanched parsley, apigenin reached the blood but only 0.22% of it appeared in urine
Eleven healthy adults ate a single serving of blanched parsley, 2 g per kilogram of body weight, far more than a garnish. Blood apigenin peaked at 127 nmol/L about 7.2 hours later, varied a lot between people, and fell below the detection limit within 28 hours. The authors conclude that a small share of food apigenin reaches the circulation. It did not test any health effect.
From a parsley drink, apigenin breakdown products in urine equaled 11.2% of the amount eaten, against 0.5% for pure apigenin
Trial in healthy men comparing pure apigenin, a parsley drink, dried powdered parsley leaves stirred into yogurt, and chamomile tea. Apigenin on its own was poorly absorbed. The parsley drink peaked in blood after about 4 hours and the powdered leaves in yogurt after about 6 hours, and chamomile tea gave 34% in urine. This study counted breakdown products, so it is not directly comparable with the blanched-parsley study above. It measured absorption only.
Drinking 1,200 mL of parsley leaf tea a day for 2 weeks did not change urine volume or stone-risk markers in healthy people
Crossover study in 20 healthy volunteers who drank parsley leaf tea or bottled water for 2 weeks each, with a 2-week break. Urine volume, pH, sodium, potassium, citric acid, uric acid and other measures did not differ. It tested people without kidney stones, so it says little about stone prevention.
Bread with 100 g of ground parsley seed plus a low-calorie diet for 4 weeks lowered a kidney-stress marker, weight and blood fats in obese women, but the changes reversed after it stopped
Study in 85 obese women in Egypt: 4 weeks on the parsley seed bread and a low-calorie diet, then 4 weeks on ordinary bread. Weight, lipids, osteopontin, creatinine and IL-1β fell, and kidney filtration (eGFR) rose, then values returned to higher levels in the second phase. It had no separate comparison group, and the diet could explain part of the first phase. This was seed bread, not leaves.
Eating 70 g of parsley with fried salmon roughly halved the mutagenicity of urine in a bacterial test
Tiny 1987 study in 3 healthy nonsmoking men. After 150 g of fried salmon alone, 6-hour urine gave almost 5,000 revertants in the Ames bacterial test, and under 2,500 when 70 g of parsley was eaten with the fish. The test shows chemical activity in bacteria, not cancer prevention, and the authors only say it warrants more attention.
Higher apigenin intake from food went with a lower ovarian cancer risk, but only after adjusting for four other flavonoids (relative risk 0.72)
Case-control study of 1,141 women with ovarian cancer and 1,183 controls, with intake of five flavonoids estimated from food questionnaires. The raw result for apigenin was borderline (0.79, range 0.59 to 1.06), total flavonoids showed no link (1.06), and the trend test was not significant. It looked at apigenin from the whole diet, not parsley itself.
Intake of five flavonols and flavones, including apigenin from food, was not linked to cancer risk in 38,408 women over 11.5 years
Prospective cohort in the Women’s Health Study with 3,234 cancers. Total and individual flavonoid intakes, apigenin among them, showed no link with total cancer or with breast, colorectal, lung, endometrial or ovarian cancer, and neither did flavonoid-rich foods such as tea, apples, broccoli and onions. Parsley was not analyzed on its own.
Boiled parsley extract fed to rats on a high-fat diet for 8 weeks lowered body weight, total and LDL cholesterol and triglycerides and raised HDL
Rat study comparing boiling, blanching and microwaving of parsley and mallow leaves. Boiling raised phenolic content about 29% and antioxidant activity 348% more than the other methods, and the boiled extract was used in the rats. Parsley worked better than mallow. These are extracts in rats, not leaves on a plate.
An aqueous parsley seed extract increased urine output in rats by blocking a salt pump in the kidney
Rats given a parsley seed extract to drink passed more urine over 24 hours than when they drank water, and kidney perfusion tests supported this. The extract reduced the activity of the Na+-K+ ATPase pump. This is a seed extract in animals, and the human trial of leaf tea above found no change in urine volume.
Parsley extract lowered blood glucose in diabetic rats but did not regenerate insulin-producing cells
Rats with diabetes induced by streptozotocin were given parsley extract. Blood glucose fell compared with untreated diabetic rats, while the number of secretory granules and cells in the pancreatic islets did not differ. The authors suggest parsley may help glucose balance but not rebuild the cells. The abstract gives no dose in food terms.
Apiole from parsley and a parsley leaf extract cut mutagen-induced bacterial colonies by 78% and 100% and blocked liver enzymes
Lab study with rat liver enzymes, bacterial human enzymes and an Ames bacterial test. Apiole and an ethanol extract of parsley leaves inhibited CYP1A enzymes and lowered mutations from a cooked-meat compound (78% for apiole, 100% for the extract), and neither was mutagenic. The authors say the same enzyme effect could cause herb-drug interactions.
Apigenin from parsley-family vegetables blocked a human drug-processing enzyme (CYP1A2) in yeast and lowered a mold toxin’s mutations
Lab study of eight plant compounds from carrots, parsnips, celery and parsley on human CYP1A2 expressed in yeast. Psoralens and apigenin were potent inhibitors, and apigenin reduced aflatoxin B1 mutagenicity. These were isolated compounds in yeast, not parsley eaten by people.
Who should be careful with parsley
Most people can eat parsley freely. Take a little care if one of these applies:
- Warfarin. A tablespoon (3.8 g) has 62.3 µg of vitamin K, 52% of the daily value, and vitamin K can change how this blood thinner works. The NHS says people on warfarin can still eat vitamin K foods but should keep the amount steady, and a Cambridge hospital leaflet names parsley among them. A big bowl of tabbouleh now and then is a bigger swing than a sprinkle each day, so tell your clinic about big changes.
- Kidney transplants and other narrow-margin medicines. A case report described a kidney transplant recipient whose blood level of the immune drug sirolimus ran too high after eating a lot of parsley. It is one case, and in the lab a parsley compound, apiole, blocked drug-processing enzymes. This is a small concern for most people. The NHS advises asking your clinic or pharmacist before taking herbal remedies or supplements.
How to choose, store and eat parsley
- Fresh leaves: a tablespoon (3.8 g) has 1 calorie, 5.05 mg of vitamin C and 8.19 mg of apigenin. Tabbouleh is the way to eat it in larger amounts.
- Blanched or as a drink: in one trial 0.22% of the apigenin from a very large serving of blanched parsley appeared in urine, and in another 11.2% of a parsley drink did as breakdown products. The two measures differ, but both show low absorption.
- Dried: dried parsley is far more concentrated by weight, since the water is gone. In one trial, 5 g of dried parsley a day gave 84 mg of apigenin, against 8.19 mg in a tablespoon of fresh.
Wash the leaves, let them drip dry, then keep them in a plastic bag in the refrigerator, as University of Illinois Extension advises. The same source calls flat-leaf the preferred parsley for cooking because it has more flavor, but no study here compares the two types for nutrition.
Sources
- Anticoagulant medicines: considerations. NHS.
- Dietary advice for patients taking warfarin. Cambridge University Hospitals NHS Foundation Trust.
- Kurtaran M, Koc NS, Aksun MS, et al. Petroselinum crispum, a commonly consumed food, affects sirolimus level in a renal transplant recipient: a case report. Ther Adv Drug Saf. 2021.
- Espinosa-Aguirre JJ, Camacho-Carranza R, Hernández-Ojeda SL, et al. Apiole, an important constituent of parsley, is a mixed-type inhibitor of the CYP1A subfamily. Mutat Res. 2024.
- Meyer H, Bolarinwa A, Wolfram G, Linseisen J. Bioavailability of apigenin from apiin-rich parsley in humans. Ann Nutr Metab. 2006.
- Borges G, Fong RY, Ensunsa JL, et al. Absorption, distribution, metabolism and excretion of apigenin and its glycosides in healthy male adults. Free Radic Biol Med. 2022.
- Janssen K, Mensink RP, Cox FJ, et al. Effects of the flavonoids quercetin and apigenin on hemostasis in healthy volunteers: results from an in vitro and a dietary supplement study. Am J Clin Nutr. 1998.
- Parsley. University of Illinois Extension.
History of parsley
Parsley is native to Greece, the Balkans, Algeria and Morocco. It is believed to have first been grown in Sardinia, and it was cultivated around the 3rd century BC. The botanist Linnaeus also named Sardinia as its wild home.
The name “parsley” comes through Old French and Medieval Latin from the Latin petroselinum, which borrowed the Greek petroselinon, “rock celery.” The earliest written form of the Greek root word selinon appears in Mycenaean Greek Linear B as se-ri-no.
Historical garden sources say parsley reached England in 1548, but literary evidence suggests it was already used there in the Anglo-Saxon period.
Cooks now use three main kinds: curly parsley, often a garnish, flat-leaf or Italian parsley, and Hamburg root parsley, which is grown for its thick roots and common in central and eastern European soups and stews. Parsley is the base of Lebanese tabbouleh, which comes from the mountains of Lebanon and Syria. Lebanon has marked a National Tabbouleh Day on the first Saturday of July since 2001. Parsley also gives falafel its green center and sits on the Passover Seder plate.
In folk medicine, parsley was used as a diuretic, a liver and stomach tonic, and for urinary stones and indigestion. Those uses rest on tradition and animal studies rather than trials. In a 2026 online survey of 100 adults with kidney stones, 52% endorsed parsley as protection against stones, and the authors list that belief among misconceptions.
Sources
- Parsley. Wikipedia.
- Tabbouleh. Wikipedia.
- Farzaei MH, Abbasabadi Z, Ardekani MR, Rahimi R, Farzaei F. Parsley: a review of ethnopharmacology, phytochemistry and biological activities. J Tradit Chin Med. 2013.
- Bahramsoltani R, Ahmadian R, Daglia M, Rahimi R. Petroselinum crispum (Mill.) Fuss (parsley): an updated review of the traditional uses, phytochemistry, and pharmacology. J Agric Food Chem. 2024.
- Raz O, Cooper A, Golomb D. Parsley, pints, and potions: unraveling patient errors in kidney stone care. World J Urol. 2026.
Frequently asked questions about parsley
Is parsley good for you?
As a food, yes, though human research on its health effects is thin. A tablespoon (3.8 g) has 1 calorie, 62.3 µg of vitamin K (52% of the daily value) and 5.05 mg of vitamin C. The best human data show that a small part of its apigenin reaches the blood, and the trials on blood clotting and urine stone markers found no effect.
Is parsley safe with warfarin?
Yes, if you keep the amount steady. A tablespoon (3.8 g) has 62.3 µg of vitamin K, so two tablespoons cover a day’s value. The NHS advises people on warfarin to keep vitamin K foods steady rather than avoid them. Tell your clinic if you plan to eat much more or less, for example a big tabbouleh each day.
Does parsley help with kidney stones?
No trial shows that it does. In 20 healthy volunteers, 1,200 mL of parsley leaf tea a day for 2 weeks changed none of the urine measures studied, including urine volume, citric acid and uric acid. A seed extract made rats pass more urine, but that is not the same as preventing stones. If you form stones, ask your doctor before relying on parsley tea.
How much parsley can you eat in a day?
No study here sets an ideal amount. Trials used 5 g of dried parsley a day for a week, 1,200 mL of leaf tea a day for 2 weeks, and a single very large serving of 2 g per kilogram of body weight. A tablespoon (3.8 g) of fresh leaves is a typical seasoning amount. If you take warfarin or a transplant drug, ask your clinic first.
Is fresh or dried parsley better?
No study compares them. The NutriScrolls figures are for fresh parsley, where a tablespoon (3.8 g) has 8.19 mg of apigenin. Dried parsley is more concentrated by weight because the water is gone: 5 g of dried parsley gave 84 mg of apigenin in one trial.
Is parsley a good source of iron?
Not in a seasoning amount. A tablespoon (3.8 g) has 0.24 mg of iron, 1% of the daily value. Eaten in larger amounts, as in tabbouleh, parsley adds more, but no study here measured how well people absorb iron from it.
How many calories are in parsley?
A tablespoon (3.8 g) of fresh parsley has 1 calorie, with 0.1 g of protein and 0.1 g of fiber. It adds flavor and some vitamins for almost no energy. No study here tested parsley for weight loss.
Is curly or flat-leaf parsley healthier?
No study here compares them. University of Illinois Extension calls flat-leaf the preferred parsley for cooking because it has more flavor, while curly parsley is often used as a garnish. The USDA record behind our figures does not split the two types.