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Herb library · Spice · Ocimum basilicum

Basil (sweet basil)

The sweet basil of the kitchen, not holy basil (tulsi). A few small trials from Iran have tested basil oil on the skin for migraine and knee arthritis and a basil syrup for anxiety. Its oil is rich in estragole, which Europe's medicines agency asks makers of herbal medicines to keep low.

Traditional use

Grown in gardens from Europe to India and China. In China the seeds were prescribed for eye complaints and the plant for vomiting and hiccough; in India, Dymock's 1890s survey records, the whole seeds (sabja) were much valued for their mucilage; in Persian medicine basil is still widely used. Europe's old herbalists argued about whether it should be taken at all, as Culpeper records.

Traditional energetics

What studies show

  • Limited

    Migraine: in a 2020 trial, 144 people with migraine rubbed on basil essential oil (2%, 4% or 6%) or a placebo every 8 hours for 3 months, alongside acetaminophen. Pain and attack frequency fell more with the higher basil doses. It is one trial.

  • Limited

    Knee osteoarthritis: in a 2024 trial, 100 people used a traditional basil oil or diclofenac gel on the knee for 4 weeks. Both groups improved and there was no difference between them; there was no placebo group.

  • Limited

    Anxiety in depression: in a 2025 single-blind trial, 60 people with major depression took basil syrup or placebo for 4 weeks; anxiety and depression scores fell more with basil. The authors say larger and longer studies are needed.

Be careful of

Cautions

  • AmountBasil contains estragole, and basil essential oil is 20–89% estragole. EMA calls estragole a genotoxic carcinogen in rodents and says the risk to people from low, food-level amounts has not been worked out. European advisers have told consumers to limit estragole-containing herbs beyond occasional kitchen use, and EMA asks that herbal medicines keep it as low as possible and be used for no more than 14 days. Concentrated oils carry far more than a seasoning does.
  • PregnancyEMA does not recommend estragole-containing herbal medicines in pregnancy or breastfeeding when they give more than 0.05 mg of estragole a day. Basil as a seasoning is not what this addresses.
  • ConditionChildren: EMA does not recommend estragole-containing herbal medicines for children up to 11 when they exceed 1 microgram of estragole per kilogram of body weight a day. On the skin, EMA advises intact skin only and no more than 2 weeks, because absorption through skin is unknown.
  • NoteSweet basil is a different plant from holy basil (tulsi); supplements and research for one do not apply to the other.
  • 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 the herb which all authors are together by the ears about, and rail at one another (like lawyers.) Galen and Dioscorides hold it not fit to be taken inwardly; and Chrysippus rails at it with downright Billingsgate rhetoric; Pliny, and the Arabian physicians, defend it.”
Nicholas Culpeper, Culpeper's Complete Herbal (1814), p. 17. See the page of Culpeper's Complete Herbal, p. 17 (opens in a new tab) · Read the full passage from Culpeper's Complete Herbal, p. 17
“The plant is recommended to be extensively sown in gardens to overcome the bad odors due to the use of fertilizers.”
G. A. Stuart, Chinese Materia Medica: Vegetable Kingdom (1911), p. 289. See the page of Chinese Materia Medica: Vegetable Kingdom, p. 289 (opens in a new tab) · Read the full passage from Chinese Materia Medica: Vegetable Kingdom, p. 289

Sources

  1. Public statement on the use of herbal medicinal products containing estragole (EMA/HMPC/137212/2005 Rev 1 Corr 1) (opens in a new tab) · EMA · read September 25, 2026
  2. Use of herbal medicinal products containing estragole - Scientific guideline (opens in a new tab) · EMA · read September 25, 2026
  3. The efficacy of topical basil essential oil on relieving migraine headaches: a randomized triple-blind study (Complement Med Res, 2020) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  4. A randomized double-blind active-controlled clinical trial on the efficacy of topical basil (Ocimum basilicum) oil in knee osteoarthritis (Front Pharmacol, 2024) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
  5. Basil (Ocimum basilicum) to alleviate anxiety in patients with major depressive disorder: a randomized placebo-controlled clinical trial (Brain Behav, 2025) — PubMed record (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.