Black Seed Oil (Nigella sativa)

Nigella sativa · thymoquinone · black cumin · kalonji · black caraway

Snapshot

Indications	Contraindications
Type 2 diabetes glycemia^1–7 Dyslipidemia⁸ Blood pressure^9–11 Body weight^{1, 5, 11–13} Inflammatory and oxidative markers¹⁴ Oral lichen planus¹⁵	Pregnancy or breastfeeding¹⁶ Prior hypersensitivity¹⁶

Black seed oil is pressed from Nigella sativa seed and carries thymoquinone as its main active constituent, acting largely through antioxidant and anti-inflammatory effects¹⁷. Supplementation is used for cardiometabolic risk: glycemic control in type 2 diabetes, lipids, blood pressure, and body weight. It is also used for inflammatory conditions such as rheumatoid arthritis and ulcerative colitis, and for non-restorative sleep. The typical patient is an adult with type 2 diabetes, prediabetes, or elevated cardiometabolic risk⁵.

Meta-analyses of randomized trials consistently show lower fasting glucose, glycated hemoglobin, total cholesterol, and low-density lipoprotein cholesterol in type 2 diabetes^{1, 18}. Oil appears more effective than powder for fasting glucose¹⁹. An overview of systematic reviews graded most outcomes as low or very low quality, so confirmation in large trials is still needed²⁰. In women with polycystic ovary syndrome, a 2026 randomized placebo-controlled trial found lower interleukin-6 and fasting glucose, with no difference in insulin resistance or hormonal measures²¹. Products listing black seed oil are numerous, sold mainly as softgels, liquids, capsules, and powders; see Form comparison.

LiverTox rates black cumin an unlikely cause of clinically apparent liver injury²². Health Canada lists pregnancy and breastfeeding as grounds not to use licensed products¹⁶. A hepatitis C trial reported occasional hypoglycemia, which is relevant where glucose-lowering medication is used²³.

Last updated October 15, 2026. Read how we make monographs.

In the full monograph

73 sources, 57 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources