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Herb library · Spice · Laurus nobilis

Bay Leaf

The dried leaf of the bay laurel tree, simmered in soups and stews and taken out before serving. A few small trials have tested it for blood sugar, cholesterol and stress. Doctors have reported a swallowed whole leaf perforating the bowel.

Traditional use

The bay tree is an old European remedy: Culpeper lists the leaves and berries for wind, coughs, the bladder and aching joints, and an oil of the berries rubbed on sore limbs. Today the leaf is mainly a kitchen herb, sometimes made into a tea.

Traditional energetics

What studies show

  • Limited

    Blood sugar and cholesterol in type 2 diabetes: a 2009 trial in Pakistan gave 40 people 1 to 3 g of ground bay leaf a day in capsules, or a placebo, for 30 days; glucose and cholesterol fell in the bay-leaf groups. It is one small, short study that has not been repeated at scale.

  • Limited

    Blood sugar after a meal: in a 2017 crossover study of 20 healthy people, cookies with 6% bay-leaf powder lowered blood sugar at 30 and 45 minutes, but the total rise over two hours was no different from plain cookies.

  • Insufficient

    Cholesterol and stress in healthy people: in a Tunisian study, 30 volunteers drank bay-leaf tea (5 g of leaves) daily for 10 days; HDL cholesterol rose, and cortisol and stress scores fell. There was no comparison group, and the authors call for larger, longer studies.

Be careful of

Cautions

  • NoteTake whole leaves out before eating. A swallowed bay leaf perforated part of the bowel in a case reported in the Canadian Journal of Surgery (1997), and the British Medical Journal published a note titled “Beware of bay leaf” (1980).
  • AllergyBay leaves contain costunolide, a strong contact allergen. A 2017 review found that some people sensitized to it can react when they eat bay leaves, and bay leaf has caused skin reactions on contact (2021 report).
  • AmountThe studies used 1 to 5 g of dried leaf a day for 10 to 30 days. Long-term safety of amounts larger than cooking uses has not been studied.
  • PregnancyNo pregnancy or breastfeeding safety information was found in the sources used here. Keep to cooking amounts.
  • InteractionIf you take medicine for diabetes, talk with your clinician before taking bay leaf as a supplement: the small studies suggest it may lower blood sugar.
  • Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.

From the old books

What herbals and dispensaries of the past printed. History, in their words.

“This is so well known that it needs no description: I shall therefore only write the virtues thereof, which are many.”
Nicholas Culpeper, Culpeper's Complete Herbal (1814), p. 18. See the page of Culpeper's Complete Herbal, p. 18 (opens in a new tab) · Read the full passage from Culpeper's Complete Herbal, p. 18
“seven of them given to a woman in sore travail of child-birth, do cause a speedy delivery, and expel the after birth, and therefore not to be taken by such as have not gone out their time, lest they procure abortion, or cause labour too soon.”
Nicholas Culpeper, Culpeper's Complete Herbal (1814), p. 18. See the page of Culpeper's Complete Herbal, p. 18 (opens in a new tab) · Read the full passage from Culpeper's Complete Herbal, p. 18

Sources

  1. Bay leaves improve glucose and lipid profile of people with type 2 diabetes (J Clin Biochem Nutr, 2009) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  2. Effect of incorporating bay leaves in cookies on postprandial glycemia, appetite, palatability, and gastrointestinal well-being (J Am Coll Nutr, 2017) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  3. Evaluation of daily Laurus nobilis tea consumption on lipid profile biomarkers in healthy volunteers (J Am Coll Nutr, 2020) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  4. Evaluation of daily Laurus nobilis tea consumption on anxiety and stress biomarkers in healthy volunteers (Arch Ital Biol, 2022) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  5. Bay leaf perforation of Meckel's diverticulum (Can J Surg, 1997) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  6. Beware of bay leaf (Br Med J, 1980) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  7. Systemic allergic dermatitis caused by sesquiterpene lactones (Contact Dermatitis, 2017) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  8. Bay leaf phytodermatitis (Contact Dermatitis, 2021) — PubMed record (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.