Black Seed (Nigella sativa) Oil: Evidence, Safety and Medicine Cautions

If you take medicines for blood sugar, blood pressure or blood thinning, or you are having surgery, talk to your prescriber or pharmacist before using black seed oil. Trials of black seed lowered blood sugar and blood pressure on average, and one case report describes a large bruise (hematoma) in a man who took black seed oil together with other drugs that affect bleeding. [1][2][3] Skin reactions to the oil, including serious ones in case reports, are also described. [4][5]

What black seed oil is

Black seed oil is pressed from the seeds of Nigella sativa L., a plant in the family Ranunculaceae. Its accepted name is confirmed in the GBIF taxonomy. [6] The seeds are also known as black cumin or black caraway. [7] The oil is a product of the seed. A result for the ground seed, a capsule or a seed extract does not automatically carry over to the oil, and the reverse is also true. For the plant itself, see Black seed (Nigella). For the tradition around it, see Black seed in Islamic and other traditions.

Traditional use

The seed has a long history as a food ingredient in Middle Eastern and Far Eastern cuisines. [7] The U.S. LactMed database notes that black seed and a related species have been used by mouth to support milk supply in India, Türkiye and the Middle East. LactMed also says no scientifically valid clinical trials support that use in humans. [4] This is traditional use. It is not proof that the oil works for any condition.

What research shows

Most human research combines seed powder, seed oil and extracts in one pool. Look at the "form" column before drawing conclusions.

Proper evidence not found in the sources we read (we searched PubMed for black seed oil trials and reviews) for black seed oil as a treatment for any disease outcome such as heart attack, stroke or diabetes complications, or for a safe amount for any person.

Safety and who should ask first

• Blood sugar and blood pressure medicines: because trials found lower blood sugar and blood pressure, ask the prescriber or pharmacist how black seed oil fits with these medicines. Do not change a prescribed medicine on your own. [8][2] See interactions by drug class and how interactions work.
• Blood thinners, antiplatelet drugs and chemotherapy: a 2026 case report describes a man on dual antiplatelet therapy and chemotherapy who developed a large hematoma and a low platelet count during a trial of black seed oil. The authors rated the link as a possible adverse drug reaction and urged clinicians to ask about herbal use. [3] One case cannot show cause, but it is a reason to tell the care team.
• Skin: LactMed states that black seed oil can cause allergic contact dermatitis. [4] A published report describes a severe drug rash with organ involvement (DRESS) after topical use. [5] See patch testing natural ingredients.
• Breastfeeding: LactMed found no data on black seed components in breast milk or on safety in infants, and says limited information indicates black seed is generally well tolerated. [4]
• Pregnancy, liver and kidney disease, and surgery: these were not described for the oil in the sources we read, so we make no claim. Lack of evidence is not proof of safety. Tell the surgical team about any oil or supplement you use. See pregnancy and breastfeeding and supplements before surgery.
• Allergic reaction: swelling of the face or throat or trouble breathing needs 911.

Quality

One toxicology assessment notes wide reported variability in the active compounds in black seed products. [7] Labels do not guarantee content. See quality testing and certifications and medicine interactions with natural ingredients.