Not All Black Seed Oil Supplements Contain What They Claim, According to ConsumerLab

White Plains, NY, January 9, 2025 —  Black seed oil and extract supplements are promoted for controlling blood pressure, cholesterol, blood sugar, and arthritis pain, and more. However, recent ConsumerLab tests revealed that some black seed oil supplements contain far less thymoquinone, a key black seed oil compound, than listed on the label. ConsumerLab also tested products to determine their amounts of omega-6 and omega-9 fatty acids, which constitute the bulk of black seed oil. Products were additionally tested for potential contamination with heavy metals (lead, cadmium, arsenic, and mercury), and bottled oils were tested to ensure they were not rancid.
 

Key Findings:

• Some Black Seed Oils Fall Short on Key Compounds: Two out of seven black seed oils and supplements selected for testing by ConsumerLab contained far less thymoquinone than claimed, including one product that contained just 41.8% of its claimed amount. A second product was found to contain only 66.6% of its claimed amount thymoquinone and also fell short on omega-9 fatty acids, containing just 76.7% of the listed amount.
• Contamination and Spoilage: Some products contained trace amounts of lead and arsenic, but none exceeded the strict limits of California, above which a warning label is required, and none contained detectable amounts of cadmium or mercury. Both bottled black seed oils were found to be just below limits that indicate spoilage (rancidity). Rancidity may not impact the effects of the oil, but it can adversely affect the taste of a product consumed as a liquid.
• Cost Does Not Indicate Quality: The cost to obtain 20 mg of thymoquinone from products ranged from 18 to 74 cents, but testing showed that price was not an indicator of quality.

Among products that passed all tests and were Approved, ConsumerLab selected Top Picks for black seed bottled oil, black seed oil in capsules or softgels, and black seed extract based on quality and cost.
 

Access the Full Report:

ConsumerLab’s full Black Seed Oil Review can now be accessed online by ConsumerLab.com members – who now number over 100,000.

The Review includes test results and comparisons for seven bottled black seed oils and black seed oil supplements selected for testing by ConsumerLab: Amazing Herbs Black Seed, Life Extension Black Cumin Seed Oil, Maju Superfoods Cold-Pressed Black Seed Oil, Prime Natural Black Seed – Organic, Swanson Black Cumin Seed Oil, Triquetra TQ-Advanced Black Seed 4x, and Zhou Black Seed Oil.

As explained in the Review, "black seed" refers to the seeds of black cumin (Nigella sativa). It is not related to is not related to the spices cumin or black caraway, or to black currant seed, a different plant that is a source of the essential fatty acid gamma-linolenic acid (GLA). Evidence from preliminary studies suggests that black seed oil may modestly lower blood sugar, blood pressure, cholesterol, and weight, and improve asthma symptoms, osteoarthritis, and thyroid status in people with Hashimoto's disease, but more research is needed to confirm these findings. The Review also discusses safety, side effects, and drug interactions with black seed oil.

Founded in 1999, ConsumerLab.com is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Membership to ConsumerLab.com is available online and provides immediate access to continually updated reviews of nearly every popular type of dietary supplement and health food, answers to reader questions, and product recalls and warnings. ConsumerLab also provides independent product testing through its voluntary Quality Certification Program. The company is privately held and based in New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.