Basil: Sweet Basil Nutrition, Fresh vs Dried and Safety

Basil is the fragrant, soft-leaved herb behind pesto, caprese salad and many Thai and Italian dishes. The kind sold in most US stores is sweet basil (Ocimum basilicum), a member of the mint family. USDA data show fresh basil is mostly water and very low in calories, yet its leaves are a notable source of vitamin K, and dried basil packs those nutrients into a far smaller spoonful. This guide covers basil nutrition for fresh and dried leaves, how the main types differ, why people who take warfarin aim for consistent vitamin K, and what the research on estragole, a natural basil compound, actually says.

Peptide Labs does not sell basil or basil products. This article is general nutrition information, not medical advice.

What is basil?

Basil belongs to the Lamiaceae family, the same plant family as mint, rosemary, oregano and sage. A 2023 review of sweet basil lists linalool, eucalyptol, estragole and eugenol as its main aroma compounds, and the balance between them is why one basil smells sweet and floral while another smells of anise or clove. Common kitchen types include:

• Sweet or Genovese basil: large, glossy green leaves; the classic pesto and tomato herb.
• Thai basil: purple stems and a firmer leaf with a licorice-like note; it holds up better in stir-fries and curries.
• Lemon and lime basil: smaller leaves with a citrus aroma.
• Purple basil: dark leaves, used much like sweet basil.
• Holy basil (tulsi): a separate species, Ocimum tenuiflorum, with a peppery, clove-like taste. It is mostly sold as a tea or capsule; see our holy basil guide for that topic.

Basil seeds, the small black seeds that swell in water for drinks and desserts, come from basil plants too but are eaten in a very different way. Our basil seeds guide covers their nutrition.

Basil nutrition: fresh and dried

The numbers below come from USDA FoodData Central (SR Legacy). Fresh basil (FDC 172232) is about 92% water, so a typical garnish adds almost no calories, protein or fiber. Its standout is vitamin K. Dried basil (FDC 171317) has lost its water, so the same nutrients are concentrated many times over per gram; in USDA data a tablespoon of ground dried basil supplies more vitamin K than a quarter cup of fresh leaves.

Per 100 grams, USDA lists fresh basil with 414.8 micrograms of vitamin K, 264 micrograms RAE of vitamin A and 18 milligrams of vitamin C. That sounds large, but nobody eats 100 grams of basil in a sitting outside of a big batch of pesto. For comparison, fresh parsley (FDC 170416) has about four times as much vitamin K per 100 grams in USDA data; our parsley guide covers that herb.

Is basil healthy?

Basil is a healthy way to add flavor, color and aroma to food without adding salt or much energy. A 2023 review describes many lab and animal studies of basil extracts and oils, but the amounts and forms used there are not what lands on a plate, and good human trials of culinary basil are scarce. The honest summary: basil is a nutritious herb that contributes vitamin K and small amounts of other nutrients, and its main value in a diet is making vegetables, beans, grains and fish taste good.

Pesto changes the picture. A classic recipe adds olive oil, cheese and nuts, so most of its calories and fat come from those ingredients rather than the basil; check the Nutrition Facts label on jarred pesto. Our guides to olive oil, pine nuts and parmesan cover those parts, and anyone with a tree nut or milk allergy should read pesto labels closely.

Basil, vitamin K and blood thinners

Vitamin K helps make proteins involved in blood clotting, which is why it matters for people who take warfarin (Coumadin) and for their clinicians. The NIH Office of Dietary Supplements calls the vitamin K and warfarin interaction serious and potentially dangerous, and says people on warfarin need to keep their vitamin K intake from food and supplements consistent, because sudden changes can raise or lower the drug’s effect. MedlinePlus advises eating consistent amounts of vitamin K foods week to week and talking to your doctor before changing your diet.

• A few torn leaves on a pizza are a small, steady amount; a large batch of pesto eaten several days in a row is a bigger swing.
• Dried basil adds up faster than fresh because it is concentrated, so heavy-handed seasoning blends count too.
• Basil-based capsules or green powders can carry concentrated vitamin K. Tell your clinician or anticoagulation clinic before starting one.

Our guide to vitamin K in foods lists the larger sources, such as leafy greens, that matter more for consistency than a garnish of basil.

What about estragole in basil?

Estragole is a natural aroma compound in basil, and also in fennel and tarragon. In rodent studies, high amounts caused liver damage and tumors through a reactive breakdown product, which is why researchers have studied it closely. A 2002 safety review by the expert panel of the Flavor and Extract Manufacturers Association, an industry group, found that this activation depends on the amount and is minimal at levels it estimated to be roughly 100 to 1,000 times typical human exposure. The panel concluded that present exposure from food, mainly spices, does not pose a significant cancer risk, while calling for more research at low exposure levels.

The research attention has shifted to concentrated sources. A 2013 study of basil-containing plant food supplements found estragole in these products and noted that powdered basil also contains nevadensin, a compound that blocked estragole activation in lab tests, while basil essential-oil products contained little of it. For cooking, the practical message is simple: basil used as an herb is a normal part of many traditional diets, while basil essential oils and concentrated extracts are a different matter to discuss with a clinician or pharmacist, especially during pregnancy.

How to choose, store and use fresh basil

Look for bright, perky leaves with no black spots or slimy patches. A 2023 review of basil shelf life notes that the herb is cold sensitive, which is why leaves stored in a cold fridge often darken. Many cooks keep a bunch at room temperature with the stems in a glass of water, loosely covered, and use it within a few days. Rinse leaves under running water just before using them, as FDA advises for fresh produce, and pat them dry.

• Tear or slice leaves right before serving; cut basil darkens quickly.
• Add fresh basil at the end of cooking to keep its aroma; Thai basil handles heat better.
• Use dried basil in sauces, soups and spice rubs that simmer, where its flavor has time to develop.
• Freeze chopped basil in a little olive oil in an ice cube tray for winter sauces.

Basil is not one of the nine major food allergens that US labels must declare, but any herb can cause a reaction. Hives, swelling or breathing trouble needs urgent care; for unclear symptoms, see an allergist, and our elimination diet guide explains why testing should be supervised. Basil’s cousin, mint, has its own guide.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Mint: Mint Leaves Nutrition and Spearmint vs Peppermint, Holy Basil (Tulsi): Benefits, Research and Side Effects, Basil Seeds (Sabja Seeds): Nutrition, Benefits and Safety, Types of Herbs: Culinary Herbs by Plant Family, Fresh and Dried.