Black seed oil — also known as N. sativa oil and black cumin oil — is championed by natural healers for its variety of health benefits. The oil is extracted from the seeds of the Nigella sativa plant, also called kalonji.

Both the oil and the seeds are used in Indian and Middle Eastern cooking.

Diabetes is a common disease that affects the body’s ability to produce and respond to insulin. Among other things, this condition results in elevated blood sugar (glucose). Treatment often includes medication to help manage blood sugar. There are two main kinds of diabetes: Type 1 and Type 2.

Research is ongoing to find alternative and complementary medicines that can help the correction of blood sugar levels. Black seed oil is the focus of some of that research. It has shown some positive results including:

  • A 2016 overview in the British Journal of Pharmaceutical Research, indicated that the role of N. sativa seeds in treating diabetes is substantially important (enhancing insulin production, glucose tolerance, and beta cell proliferation). The overview concluded that the seeds also can play a significant role in the treatment of diabetes complications such as nephropathy, neuropathy, and atherosclerosis.
  • A 2013 study concluded that high doses of N. sativa oil significantly elevated serum insulin levels in diabetic rats, providing a therapeutic effect.
  • A 2017 study concluded that black cumin seed oil over time reduced HbA1c — the average blood glucose levels — by increasing insulin production, decreasing insulin resistance, stimulating cellular activity, and decreasing intestinal insulin absorption.
  • A 2014 study concluded that adding turmeric and black seed to the diet of diabetic rats reduced blood glucose, water, and food intake.
  • A 2017 review of clinical trials concluded that along with other effects, the hypoglycemic effect of N. sativa has been sufficiently studied and understood to allow for the next phase of clinical trials or drug development.

According to a 2015 medical journal review, thymoquinone might be one of the most potent parts of black seed oil’s hypoglycemic effect. The review called for molecular and toxicological studies to identify effective and safe ingredients of the seed for use on diabetic patients in clinical trials.

Among active ingredients of black seed oil are the antioxidants:

  • thymoquinone
  • beta-sisterol
  • nigellone

The oil also contains amino acids such as:

  • linoleic
  • oleic
  • palmitic
  • stearic

Also found in black seed oil are:

Studies have shown promising results on black seed oil as a potential treatment for diabetes. However, large-scale clinical trials are still needed to fully understand its safety for people who have other health issues (in addition to diabetes), and to determine how black seed oil interacts with other medications.

If you’re considering using black seed oil to help manage your diabetes, talk with your doctor first. They can provide pros and cons for how black seed oil will impact your current health. They can also make recommendations for how often you should monitor your blood sugar as you begin.

After a conversation with your doctor, if you decide to try black seed oil, make sure that the brand you use has been tested for efficacy and safety. The Food and Drug Administration (FDA), does not monitor the sale of these supplements in the United States.