Marjoram

The dried leaf and flowering top are taken as an infusion. Marjoram is given as a carminative for gas, bloating and digestive cramps, as a mild nervine for tension and sleeplessness, as an antispasmodic for menstrual and muscle cramps, and as a warming remedy for coughs and colds.

In English folk use the leaves were taken for colds, bronchial coughs and whooping cough ^{1Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →}.

In traditional Iranian medicine the leaves are used as a carminative, an antitussive, an antiseptic and an antidote. They are also taken for digestive disorders, headache, epilepsy, melancholy with flatulence, facial paralysis, ear pain, shortness of breath, heart pain and irregular heartbeat, and to bring on menstruation ^{1Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →}.

In Morocco marjoram is used for infant colic, abdominal discomfort and diarrhoea, and the leaves as a remedy for high blood pressure ^{1,21Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →Reference 21Makrane et al. · 2019In vitroOriganum majorana L. extract exhibits positive cooperative effects on the main mechanisms involved in acute infectious diarrhea — in vitro / ex vivoView study →}. In Egypt it is a common remedy for abdominal colic, and the leaves are taken for colds and chills and against intestinal parasites ^{1,12,29Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →Reference 12Taha et al. · 2023AnimalPhytochemical analysis of Origanum majorana L. extract and its antioxidant, anti-inflammatory and immunomodulatory effects against experimentally induced colitis, downregulating Th17 cells — animal modelView study →Reference 29Méabed et al. · 2018In vitroChemical analysis of aqueous extracts of Origanum majorana and Foeniculum vulgare and their efficacy on Blastocystis spp. cysts — in vitroView study →}.

It is reputed in local folk medicine to restore hormonal balance and regulate the menstrual cycle ^{5,9Reference 5Haj-Husein et al. · 2016RCTThe effect of marjoram (Origanum majorana) tea on the hormonal profile of women with polycystic ovary syndrome: a randomised controlled pilot study — randomised controlled trialView study →Reference 9Rababa’h et al. · 2020AnimalThe ameliorative effects of marjoram in dehydroepiandrosterone-induced polycystic ovary syndrome in rats — animal modelView study →}.

In Turkey the essential oil is used for asthma, indigestion, headache and rheumatism, and in Azerbaijan for flatulence and nervousness and as a diuretic and sedative ^{1Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →}.

In India marjoram essential oil is used for toothache and to soothe sore joints and muscles ^{1Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →}.

In a randomised, double-blind, placebo-controlled pilot trial in people with Parkinson’s disease, 30 drank rosmarinic acid-rich marjoram tea and 25 a placebo tea once daily for 30 days. The tea group had higher superoxide dismutase and catalase and lower carbonylated (oxidatively damaged) proteins than the placebo group at the end ^{4Reference 4Chbili et al. · 2025RCTEffect of Origanum majorana tea on oxidative stress biomarkers in Parkinson’s disease: a randomised placebo-controlled pilot study — randomised controlled trialView study →}.

Methanolic and aqueous leaf extracts show strong free-radical scavenging in DPPH, ABTS and FRAP assays ^{1Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →}. The same antioxidant effect appears in marjoram’s protection against cisplatin- and ciprofloxacin-induced kidney damage ^{15,16Reference 15Soliman et al. · 2016AnimalOriganum majorana attenuates nephrotoxicity of cisplatin anticancer drug through ameliorating oxidative stress — animal modelView study →Reference 16Hussein et al. · 2022AnimalOriganum majorana attenuates ciprofloxacin-induced nephropathy in rats — animal modelView study →} and isoproterenol-induced heart injury ^{14Reference 14Rababa’h et al. · 2021AnimalOriganum majorana L. extract protects against isoproterenol-induced cardiotoxicity in rats — animal modelView study →} in rats, where it restored glutathione, SOD and catalase and lowered markers of lipid peroxidation.

Gap: The human trial was a small pilot (n = 55) in one disease population; there is no dose-ranging or general-population antioxidant trial.

In a randomised, double-blind, placebo-controlled pilot trial, 25 women with polycystic ovary syndrome drank marjoram tea (14) or a placebo tea (11) twice daily for one month. The tea lowered DHEA-S, an adrenal androgen, compared with placebo (P = 0.05). Fasting insulin fell within the tea group, but not significantly against placebo (P = 0.08), and HOMA-IR insulin resistance improved against placebo without a significant fall within the group ^{5Reference 5Haj-Husein et al. · 2016RCTThe effect of marjoram (Origanum majorana) tea on the hormonal profile of women with polycystic ovary syndrome: a randomised controlled pilot study — randomised controlled trialView study →}.

A second pilot trial gave 60 women a marjoram-and-cinnamon tea or a placebo tea twice daily for three months, and 36 completed it. FSH rose and anti-Müllerian hormone fell in the tea group, but AMH also fell in the placebo group. No major side effects were reported ^{8Reference 8Majeed et al. · 2025RCTSafety and effectiveness of marjoram and cinnamon herbal tea supplementation in managing polycystic ovary syndrome: a pilot randomised, double-blind, controlled trial — randomised controlled trialView study →}.

In rat models of PCOS induced by DHEA or letrozole, marjoram extract improved the hormonal profile, raised adiponectin (a marker of insulin sensitivity), raised ovarian antioxidant enzymes and lowered inflammation. The letrozole study traced the effect to Nrf2 activation and NF-κB suppression ^{9,10,11Reference 9Rababa’h et al. · 2020AnimalThe ameliorative effects of marjoram in dehydroepiandrosterone-induced polycystic ovary syndrome in rats — animal modelView study →Reference 10Al-Harbi et al. · 2025AnimalProtective effect of marjoram against letrozole-induced ovarian damage in rats with polycystic ovarian syndrome (Nrf2 activation, NF-κB suppression) — animal modelView study →Reference 11Elfiky et al. · 2025AnimalExploring the therapeutic potential of marjoram (Origanum majorana L.) in polycystic ovary syndrome: serum metabolomics, network pharmacology and experimental validation — animal modelView study →}.

Gap: Both human trials are small pilots, one of them testing a two-herb combination, and no trial has measured clinical endpoints such as ovulation or cycle regularity.

In acetic-acid-induced ulcerative colitis in rats, a methanolic extract suppressed NF-κB, TNF-α, IL-1β, IL-6 and COX-2, downregulated the JAK2/STAT3 axis and the Th17 response, and acted through Nrf2/HO-1. The extract and the drug sulfasalazine both improved the disease activity index ^{12Reference 12Taha et al. · 2023AnimalPhytochemical analysis of Origanum majorana L. extract and its antioxidant, anti-inflammatory and immunomodulatory effects against experimentally induced colitis, downregulating Th17 cells — animal modelView study →}.

In isoproterenol cardiotoxicity in rats it lowered CRP, IL-6, IL-13 and TNF-α ^{14Reference 14Rababa’h et al. · 2021AnimalOriganum majorana L. extract protects against isoproterenol-induced cardiotoxicity in rats — animal modelView study →}, and in LPS-induced neuroinflammation in mice it reduced COX-2 in the brain ^{18Reference 18Wagdy et al. · 2023AnimalOriganum majorana L. protects against neuroinflammation-mediated cognitive impairment: a phyto-pharmacological study — animal modelView study →}. In bile-duct-ligated rats, of the inflammatory and fibrosis genes measured, it significantly reduced only TGF-β ^{13Reference 13Gheitasi et al. · 2021AnimalAntioxidant and anti-inflammatory effects of Origanum majorana L. methanolic extract on bile-duct ligation in male rats — animal modelView study →}.

Rosmarinic acid and its derivatives are the main phenolics of the extract, and rosmarinic acid on its own protected microglial cells from oxidative stress ^{18Reference 18Wagdy et al. · 2023AnimalOriganum majorana L. protects against neuroinflammation-mediated cognitive impairment: a phyto-pharmacological study — animal modelView study →}.

Every dataset is rodent or cell-based, at extract doses (often 100–500 mg/kg) far above culinary intake, with no human trial for any inflammatory condition.

In rats, an ethanol extract at 250 and 500 mg/kg reduced gastric ulcers caused by cold-restraint stress, indomethacin, ethanol, concentrated salt and sodium hydroxide. It lowered basal acid secretion, replenished protective gastric mucus and non-protein sulfhydryls, and lowered lipid peroxidation. An acute toxicity test in mice showed a wide margin of safety ^{17Reference 17Al-Howiriny et al. · 2009AnimalProtective effect of Origanum majorana L. ‘Marjoram’ on various models of gastric mucosal injury in rats — animal modelView study →}.

A methanol extract of the herb inhibited Helicobacter pylori in vitro at an MIC of 50 µg/mL ^{25Reference 25Mahady et al. · 2005In vitroIn vitro susceptibility of Helicobacter pylori to botanical extracts used traditionally for the treatment of gastrointestinal disorders — in vitroView study →}, and the essential oil was more potent, at 11.4 µg/mL ^{26Reference 26Elkousy et al. · 2022In vitroGC/MS analysis and potential synergistic effect of mandarin and marjoram oils on Helicobacter pylori — in vitroView study →}.

All of it is preclinical at doses far above tea strength, and the H. pylori work is test-tube only.

In a screen of 139 herbs and spices, marjoram ethanol extract was the strongest acetylcholinesterase (AChE) inhibitor, and the activity was traced to ursolic acid ^{20Reference 20Chung et al. · 2001In vitroInhibitory effect of ursolic acid purified from Origanum majorana L. on the acetylcholinesterase — in vitroView study →}.

The essential oil improved memory and inhibited AChE in a scopolamine-amnesia zebrafish model ^{19Reference 19Brinza et al. · 2025AnimalNeuroprotective potential of Origanum majorana L. essential oil against scopolamine-induced memory deficits and oxidative stress in a zebrafish model — animal modelView study →}.

A hydroalcoholic extract, given by injection, protected mice against LPS-induced neuroinflammation and memory loss, reducing astrogliosis and COX-2 ^{18Reference 18Wagdy et al. · 2023AnimalOriganum majorana L. protects against neuroinflammation-mediated cognitive impairment: a phyto-pharmacological study — animal modelView study →}.

In a Parkinson’s disease pilot trial in which 51 of 60 patients completed 30 days, marjoram tea improved non-motor symptom and depression scores. The motor score did not change significantly (p = 0.07) ^{6Reference 6Chbili et al. · 2021RCTThe effect of Origanum majorana tea on motor and non-motor symptoms in patients with idiopathic Parkinson’s disease: a randomised controlled pilot study — randomised controlled trialView study →}.

Gap: The human trial improved secondary endpoints only, and the AChE and cognition work is entirely animal, in vitro or on the essential oil.

In a randomised controlled trial, 57 nurses in a COVID-19 intensive care unit inhaled 3% marjoram essential oil (29) or almond oil (28) for two hours during a shift. State anxiety and anxiety ratings did not differ between the groups after the shift. Within the marjoram group, state anxiety, anxiety ratings and stress ratings were lower after the shift than before, and heart rate rose slightly ^{7Reference 7Lee et al. · 2023RCTInhalation of Origanum majorana L. essential oil while working reduces perceived stress and anxiety levels of nurses in a COVID-19 intensive care unit — randomised controlled trialView study →}.

The trial tested inhaled essential oil, not the tea or the culinary herb.

Gap: A single small trial of essential-oil inhalation, with no difference from control; no study of the tea or oral herb for anxiety.

In bile-duct-ligation cholestasis in rats, a methanolic extract (300 mg/kg for 7 days) raised catalase and reduced the fibrosis marker TGF-β. It lowered ALT and AST, but not significantly, and had a minor effect on liver histology. The authors described the effect as moderate ^{13Reference 13Gheitasi et al. · 2021AnimalAntioxidant and anti-inflammatory effects of Origanum majorana L. methanolic extract on bile-duct ligation in male rats — animal modelView study →}.

A toxicology study reported lower ALT, AST and LDH in treated rats ^{28Reference 28Beceren et al. · 2025In vitroToxicological assessment of Origanum majorana L.: evaluation of its cytotoxicity, genotoxicity and acute oral toxicity — animal model / in vitroView study →}.

Gap: The main study was partly null on the key liver enzymes; no human data exist.

In isolated mouse and rat intestine, an aqueous marjoram extract relaxed intestinal smooth muscle, blocked forskolin-driven chloride secretion and stimulated sodium (and so water) absorption, each in a concentration-dependent way ^{21Reference 21Makrane et al. · 2019In vitroOriganum majorana L. extract exhibits positive cooperative effects on the main mechanisms involved in acute infectious diarrhea — in vitro / ex vivoView study →}. Moroccan folk medicine uses the herb for infant colic, abdominal discomfort and diarrhoea ^{21Reference 21Makrane et al. · 2019In vitroOriganum majorana L. extract exhibits positive cooperative effects on the main mechanisms involved in acute infectious diarrhea — in vitro / ex vivoView study →}.

This is tissue-bath pharmacology; no whole-animal or human antidiarrhoeal trial has been done.

Marjoram essential oil reduced the viability and colony growth of two human non-small-cell lung cancer lines, partly through caspase-dependent cell death and survivin downregulation. It slowed xenograft tumour growth and lymph-node metastasis in mice, and three months of treatment did not affect blood, liver or kidney function ^{22Reference 22Arafat et al. · 2022In vitroOriganum majorana essential oil decreases lung tumor growth and metastasis in vitro and in vivo — animal modelView study →}.

In colorectal cancer cells the oil triggered p38-MAPK-mediated apoptosis and protective autophagy ^{23Reference 23Athamneh et al. · 2020In vitroOriganum majorana essential oil triggers p38-MAPK-mediated protective autophagy, apoptosis and caspase-dependent cleavage of P70S6K in colorectal cancer cells — in vitroView study →}.

Gap: All data are from cell lines and mice using the essential oil, not the tea or culinary herb, and there is no human evidence.

A methanol leaf extract inhibited a panel of bacteria and fungi ^{27Reference 27Leeja et al. · 2007In vitroAntimicrobial activity of methanol extract of Origanum majorana L. (Sweet marjoram) — in vitroView study →}.

Isolated phenolics including arbutin and rosmarinic acid inhibited biofilm formation and efflux pumps in MRSA and E. coli ^{24Reference 24Kincses et al. · 2025In vitroPhenolic compounds from Origanum majorana with biofilm-inhibitory activity against methicillin-resistant Staphylococcus aureus and Escherichia coli strains — in vitroView study →}.

The herb and its oil inhibited H. pylori ^{25,26Reference 25Mahady et al. · 2005In vitroIn vitro susceptibility of Helicobacter pylori to botanical extracts used traditionally for the treatment of gastrointestinal disorders — in vitroView study →Reference 26Elkousy et al. · 2022In vitroGC/MS analysis and potential synergistic effect of mandarin and marjoram oils on Helicobacter pylori — in vitroView study →}. An aqueous extract at 400 µg/mL cleared 96% of Blastocystis cysts after 48 hours and all of them after 72 hours, close to the drug nitazoxanide at 500 µg/mL ^{29Reference 29Méabed et al. · 2018In vitroChemical analysis of aqueous extracts of Origanum majorana and Foeniculum vulgare and their efficacy on Blastocystis spp. cysts — in vitroView study →}.

The essential oil is consistently more potent than the water-soluble herb. The work is in vitro, with no infection model and no clinical data.

The culinary herb and tea. Marjoram is very low-risk as a food and a dried-leaf tea. No serious side effects were reported in the small human trials of the tea ^{4,5,6,8Reference 4Chbili et al. · 2025RCTEffect of Origanum majorana tea on oxidative stress biomarkers in Parkinson’s disease: a randomised placebo-controlled pilot study — randomised controlled trialView study →Reference 5Haj-Husein et al. · 2016RCTThe effect of marjoram (Origanum majorana) tea on the hormonal profile of women with polycystic ovary syndrome: a randomised controlled pilot study — randomised controlled trialView study →Reference 6Chbili et al. · 2021RCTThe effect of Origanum majorana tea on motor and non-motor symptoms in patients with idiopathic Parkinson’s disease: a randomised controlled pilot study — randomised controlled trialView study →Reference 8Majeed et al. · 2025RCTSafety and effectiveness of marjoram and cinnamon herbal tea supplementation in managing polycystic ovary syndrome: a pilot randomised, double-blind, controlled trial — randomised controlled trialView study →}.

Concentrated extracts. In an OECD-guideline acute oral toxicity study, a methanolic leaf extract caused no deaths or visible toxicity in rats at up to 2,000 mg/kg, with liver and kidney function preserved. This places it in GHS Category 5, the lowest acute-hazard class. In the same study, comet and micronucleus tests on fibroblast cells showed dose-dependent DNA damage, and the authors placed the extract in GHS Category 2 for germ-cell mutagenicity ^{28Reference 28Beceren et al. · 2025In vitroToxicological assessment of Origanum majorana L.: evaluation of its cytotoxicity, genotoxicity and acute oral toxicity — animal model / in vitroView study →}. This applies to concentrated extracts at high doses, not to cooking or tea.

The essential oil. The oil is far more concentrated than the herb. Use it diluted in a carrier oil or by inhalation, and do not take it internally.

Blood thinners. Marjoram extracts inhibited platelet adhesion and aggregation in laboratory tests ^{1Reference 1Bina et al. · 2017ReviewSweet Marjoram: A Review of Ethnopharmacology, Phytochemistry, and Biological Activities — reviewView study →}. No study has looked at the herb alongside anticoagulant drugs, and no clinical drug-interaction study of marjoram exists.