Marjoram: a kitchen herb tested only as a tea

Marjoram has been tested in people only as a medicinal tea, never in the amounts you sprinkle on food. In one of four small randomized trials, 25 women with polycystic ovary syndrome drank marjoram tea twice a day for a month. DHEA-S fell by 1.4 µmol/L, a change that reached significance against placebo only at P = 0.05, and the fall in fasting insulin was not significant against placebo (P = 0.08). The pilot had 14 women on tea and 11 on placebo, and the abstract does not give the amount of tea. The composition numbers look large. Dried marjoram lists 82.7 mg iron and 622 mcg vitamin K per 3.5 oz (100 g), from one US record that the UK table repeats exactly. A 0.6 g teaspoon gives about 0.5 mg iron and 3.7 mcg vitamin K.

The numbers, per 3.5 oz (100 g)

How much is actually in it

• Dried marjoram lists 82.7 mg iron, 1,990 mg calcium and 622 ug vitamin K per 3.5 oz (100 g), but a 0.6 g teaspoon supplies only about 0.5 mg iron and 3.7 ug vitamin K. — US food composition, one record Evidence C source
  Per 100 g: iron 82.71 mg, calcium 1990 mg, vitamin K 621.7 ug, fiber 40.3 g, 271 calories; per 1 tsp (0.6 g): iron 0.50 mg, calcium 11.9 mg, vitamin K 3.7 ug

What a real portion looks like

• In a survey of 270 Polish adults, marjoram was among the five most often eaten herbs in omnivores, with all herbs and spices together averaging 22.4 g a day. — 270 adults aged 19 to 67 (208 omnivores, 62 vegans), Poland (n = 270) Evidence C source
  Marjoram in top 5 for omnivores, not for vegans; total condiments 22.4 +/- 18.4 g/day omnivores

What it does to your health

• In a 1-month randomized placebo-controlled pilot in 25 women with PCOS, marjoram tea twice daily lowered DHEA-S by 1.4 umol/L, significant against placebo only at P = 0.05. — Twenty-five women with polycystic ovary syndrome, 1 month (n = 25) Evidence B source
  DHEA-S -1.4 (SD 0.5) umol/L, fasting insulin -1.9 (0.8) uU/mL within group; vs placebo DHEA-S P = 0.05, insulin P = 0.08
• In a 30-day randomized double-blind trial in 60 people with Parkinson's disease, marjoram tea did not improve motor scores but improved non-motor and depression scores. — Sixty patients with idiopathic Parkinson's disease on conventional medication, 30 days (n = 60) Evidence B source
  UPDRS-III 18.76 to 16.52, p = 0.069; NMSS and BDI improved, p < 0.0001; no side effects; 51 completed
• In a 30-day randomized placebo-controlled trial in 55 people, daily marjoram tea raised blood antioxidant enzymes, with SOD up 19.28 U/mg from baseline. — 55 volunteers (30 marjoram tea, 25 placebo tea), 30 days (n = 55) Evidence B source
  SOD +19.28 U/mg, catalase +130.1 umol/L, carbonylated protein -0.18 nmol/mg vs Day 1; higher than control at Day 31

Safety, limits and interactions

• In a 3-month randomized placebo-controlled trial of marjoram and cinnamon tea in 60 women with PCOS, no major side effects were reported, only mild colicky pain and bitter taste. — Sixty women aged 16-36 with untreated PCOS; 36 completed (21 herbal, 15 placebo) (n = 60) Evidence B source
  No major adverse effects; minor: mild colicky abdominal pain, bitter taste; AMH fell in both arms
• The EU herbal monograph does not recommend marjoram as a medicine in pregnancy or breastfeeding because safety has not been established. — pregnant and breastfeeding women (medicinal use) Evidence E source
  Use in pregnancy and lactation not recommended; no fertility data
• One case report describes systemic allergic reactions to oregano and thyme with positive skin tests to marjoram and other mint-family herbs except basil and lavender. — one patient, ten controls (n = 1) Evidence D source
  Positive prick-by-prick tests to Labiatae herbs except basil and lavender; specific IgE to all herbs tested

What people believe that the data does not support

• The EU monograph supports marjoram tea only as a traditional remedy for mild bloating and wind, at 2 to 8 g a day, and rules it out for people allergic to the mint family. — adults and elderly (medicinal tea) Evidence E source
  Traditional use only; daily dose 2-8 g; contraindicated in Lamiaceae hypersensitivity

What is still unknown

• The UK food table gives dried marjoram the same 82.7 mg iron and 1,990 mg calcium per 3.5 oz (100 g) as the US record, so there is no independent second measurement. — UK food composition Evidence C source
  CoFID 13-835: iron 82.70 mg, calcium 1990 mg, potassium 1520 mg, 271 calories per 3.5 oz (100 g)

The bottom line

In 60 people with Parkinson's disease on their usual medication, 30 days of marjoram tea did not significantly improve motor scores (18.76 to 16.52, p = 0.069). Non-motor symptom and depression scores improved (p < 0.0001), and the abstract does not report how they compared with placebo. A 30-day trial in 55 volunteers found blood antioxidant enzymes rose, with SOD up 19.28 U/mg from baseline. That is a biomarker, and the abstract is unclear about who the volunteers were. All three trials are small and short, and none used culinary amounts. In a survey of 270 Polish adults, marjoram was among the five herbs omnivores ate most often, with all herbs and spices together averaging 22.4 g a day. The abstract gives no grams for marjoram itself. The EU herbal monograph accepts marjoram tea only as a traditional remedy for mild bloating and wind, at 2 to 8 g of herb a day, based on long-standing use with no clinical efficacy data behind it. The same monograph rules marjoram tea out for anyone allergic to plants of the mint family. It does not recommend it in pregnancy or breastfeeding, because safety has not been established. Both points are written for medicinal tea doses, and the monograph does not address seasoning amounts. One case report describes a patient with systemic reactions to oregano and thyme who also tested positive to marjoram on a skin test. That is a single case. In a 3-month trial of marjoram and cinnamon tea in 60 women with PCOS, nobody reported major side effects. Minor ones were mild colicky pain and a bitter taste, only 36 of the 60 women finished, and the cinnamon means the result cannot be pinned on marjoram alone.

Sources

1. mjr-daily-r7-09 · food composition data
   Spices, marjoram, dried | Iron 82.71 MG per 100 g | Calcium 1990 MG | Vitamin K 621.7 UG | Fiber 40.3 G | Energy 271 KCAL | 1 tsp 0.6 g
   USDA SR Legacy 2019, Spices, marjoram, dried (FDC 170928, NDB 2023) · checked 2026-10-01
2. mjr-daily-r7-08 · cross-sectional study
   The study group consisted of 270 adults aged 19 to 67 years, including 205 women and 65 men. ... The five most frequently eaten herbs among omnivores were parsley, garlic, dill, marjoram and basil, while among vegans they were garlic, parsley, ginger, basil and dill. An average intake of all condiments included in the study was 22.4 ± 18.4 g/day and 25.8 ± 25.9 g/day for both omnivores and vegans, respectively (p = 0.007).
   Nutrients, 2020 · checked 2026-10-01
3. mjr-daily-r7-01 · randomized controlled trial
   Twenty-five patients were assigned to receive marjoram tea or a placebo tea twice daily for 1 month (intervention group: n = 14; placebo group: n = 11). ... Marjoram tea significantly reduced DHEA-S and fasting insulin levels (P < 0.05) by a mean (SD) of 1.4 (0.5) μmol L(-1) and 1.9 (0.8) μU mL(-1) , respectively. In comparison to the placebo group, the change was only significant for DHEA-S (P = 0.05) but not for insulin (P = 0.08).
   Journal of Human Nutrition and Dietetics, 2016 · checked 2026-10-01
4. mjr-daily-r7-02 · randomized controlled trial
   Sixty patients with idiopathic Parkinson's disease and under conventional medication were enrolled voluntarily in the study. All participants were randomized on double-blind to placebo or Origanum majorana. ... Upon completion of 30 days of treatment, Origanum majorana tea consumption did not decrease the UPDRSIII score ([UPDRSIII] D0 = 18.76 ± 8.58, D30 = 16.52 ± 7.96, p = 0.069) at the p value was 0.07. However, a statistically significant improvement was noted in NMSS and BDI scores (p < 0.0001 and p < 0.0001, respectively).
   Parkinsonism and Related Disorders, 2021 · checked 2026-10-01
5. mjr-daily-r7-03 · randomized controlled trial
   Participants were randomly assigned to receive either Omt (experimental group, n = 30) or a placebo tea (control group, n = 25) once daily for 30 consecutive days. ... In the experimental group, Day31 measurements showed a significant increase in SOD (19.28 U/mg) and catalase (130.1 µmol/L) compared to Day1, while carbonylated protein levels decreased by 0.18 nmol/mg protein.
   Neuroscience, 2025 · checked 2026-10-01
6. mjr-daily-r7-04 · randomized controlled trial
   The pilot study was set as randomized, double-blind, placebo-controlled clinical trial. The gynecologists, and the patients were blinded to the study group category. Of eighty women, only Sixty with untreated PCOS were enrolled in the study and randomly allocated to either the intervention (n = 30) or placebo group (n = 30) using Random Allocation Software, version 1.0.0. ... None of the participants reported any major side effects. In the intervention group, minor side effects included mild colicky abdominal pain and bitter and bad taste.
   Annals of Medicine and Surgery, 2025 · checked 2026-10-01
7. mjr-daily-r7-05 · agency guidance
   Safety during pregnancy and lactation has not been established. In the absence of sufficient data, the use during pregnancy and lactation is not recommended.
   EMA/HMPC, European Union herbal monograph on Origanum majorana L., herba, 2016 · checked 2026-10-01
8. mjr-daily-r7-07 · case report
   These herbs belong to the Lamiaceae (Labiatae) family which comprises other plants such as hyssop (Hyssopus officinalis), basil (Ocimum basilicum), marjoram (Origanum majorana), mint (Mentha piperita), sage (Salvia officinalis) and lavender (Lavandula officinalis). ... tests were negative with basil and lavender, and positive with all the others when we used the prick by prick technique.
   Ann Allergy Asthma Immunol, 1996 · checked 2026-10-01
9. mjr-daily-r7-06 · agency guidance
   Traditional herbal medicinal product used for the symptomatic relief of mild spasmodic gastro-intestinal complaints such as bloating and flatulence. ... Daily dose: 2-8 g ... Hypersensitivity to the active substance or to other plants of the Lamiaceae family.
   EMA/HMPC, European Union herbal monograph on Origanum majorana L., herba, 2016 · checked 2026-10-01
10. mjr-daily-r7-10 · food composition data
    13-835 Marjoram, dried | Iron (mg) 82.70 | Calcium (mg) 1990 | Potassium (mg) 1520 | Energy (kcal) 271
    CoFID 2021 (Public Health England, OGL v3.0), code 13-835 Marjoram, dried · checked 2026-10-01