What Is Black Seed Oil?

Black seed oil is extracted from the seeds of Nigella sativa, a plant native to southwest Asia. It is used by some for the treatment of asthma, diabetes, hypertension, weight loss, and other conditions. One of its key components is thymoquinone, a compound with antioxidant properties. There is scientific evidence to support some, but not all uses for black seed oil.

Black seed oil has a long history of use dating back over 2000 years. In fact, according to some sources, it was discovered in the tomb of King Tut. The oil is sold by supplement retailers for topical use and in capsule form for oral consumption. Nigella sativa seeds are sometimes used in Middle Eastern and Indian cuisine, and have a slightly bitter taste.

What Is Black Seed Oil Used For?

Although research on the health effects of black seed oil is fairly limited, there's some evidence that it may offer certain potential benefits. Here's a look at several key findings from available studies.

Rheumatoid Arthritis

Black seed oil may aid in the treatment of rheumatoid arthritis, according to a small study published in Immunological Investigations in 2016.

For the study, 43 women with mild-to-moderate rheumatoid arthritis took black seed oil capsules or a placebo every day for one month. Treatment with black seed oil led to a reduction in arthritis symptoms (as assessed by a clinical rating scale), blood levels of inflammatory markers, and the number of swollen joints.

Nasal Inflammation

Black seed oil shows promise in the treatment of allergies. In a 2011 study published in the American Journal of Otolaryngology, for instance, black seed oil was found to reduce the presence of nasal congestion and itching, runny nose, and sneezing after two weeks.

Another report published in 2018 analyzed data to determine if black seed oil could help in the treatment of sinusitis. Study authors concluded that the oil has therapeutic potential in the treatment of the condition due to its anti-inflammatory, antioxidant, antihistaminic, immune-modulator, antimicrobial, and analgesic effects.

Diabetes

Black seed oil may be of some benefit to people with diabetes, according to a review published in Complementary Therapies in Medicine in 2015.

Researchers analyzed previously published studies on the use of Nigella sativa for diabetes and concluded that it could improve blood sugar and cholesterol levels in diabetes models but noted that clinical trials are necessary to clarify the effects.

Another research review published in 2017 confirmed these findings.

Asthma

Preliminary research suggests that black seed oil may offer benefits to people with asthma.

For example, a study published in Phytotherapy Research in 2017 found that people with asthma who took black seed oil capsules had a significant improvement in asthma control compared with those who took a placebo.

Obesity

Black seed oil may reduce risk factors in women who are obese, according to a study.

For the study, women consumed Nigella sativa oil or a placebo while following a low-calorie diet for eight weeks. At the study's end, weight, waist circumference, and triglyceride levels had decreased by more in the group that took the Nigella sativa oil.

Another eight-week study combined the use of aerobic exercise with black seed oil supplementation in a trial with overweight sedentary women. Researchers found that this treatment combination provided benefits including lower cholesterol levels.

Other Uses

Black seed oil is also used as a remedy for conditions such as allergies, asthma, diabetes, headaches, high blood pressure, and digestive disorders.

In addition, black seed oil is said to boost the immune system, reduce inflammation, and fight infections.

The oil is used topically for skin and hair concerns, such as acne, dry hair, psoriasis, hair growth, and dry skin.

Possible Side Effects

Very little is known about the safety of using black seed oil long-term or in amounts higher than what's normally found in food. However, according to a report, a component of black seed oil known as melanthin may be toxic in larger amounts.

In particular, there's some concern that taking too much black seed oil may harm your liver and kidneys.

There's also some evidence that applying black seed oil directly to the skin may cause an allergic skin rash known as allergic contact dermatitis in some individuals.

In a case report, a woman developed fluid-filled skin blisters after applying Nigella sativa oil to the skin. She also ingested the oil and the report's authors state it is possible that the blisters were part of a systemic reaction (such as toxic epidermal necrolysis).

It's also possible that black seed oil may interact with many common medications, such as beta-blockers.

For this and other reasons, be sure to talk with your healthcare provider if you're considering taking black seed oil. You shouldn't stop any of your medications without speaking with your healthcare provider, nor should you delay or avoid conventional treatment.

Pregnant women (or women trying to become pregnant) and those breastfeeding shouldn't use black seed oil.

Dosage and Preparation

There is not enough scientific evidence to establish a recommended dose of black seed oil. The right dose for you may depend on your age, health, and other factors.

Various doses of black seed oil have been studied in research.

For example, in studies investigating the effects of black seed oil on patients with breast pain, a gel containing 30% black seed oil was applied to the breasts every day for two menstrual cycles.

In studies investigating whether or not black seed oil can improve sperm function, a dose of 2.5 mL of black seed oil was used twice daily for two months.

To get advice regarding the best dose for you, speak to your healthcare provider.

What to Look For

Widely available for purchase online, black seed oil is sold in many natural-foods stores and in stores specializing in dietary supplements.

When choosing an oil, many consumers prefer to buy a product that is cold-pressed and organic to make sure that the oil is in its most natural state. Read labels carefully to make sure that other ingredients haven't been added to the product you choose.

Also, it's important to keep in mind that dietary supplements are largely unregulated by the U.S. Food and Drug Administration (FDA). It is illegal to market a dietary supplement product as a treatment or cure for a specific disease or to alleviate the symptoms of a disease. The FDA does not test products for safety or effectiveness.

You may choose to look for familiar brands or products that have been certified by ConsumerLabs, The U.S. Pharmacopeial Convention, or NSF International. These organizations don't guarantee that a product is safe or effective, but they do provide a certain level of testing for quality.

A Word From Verywell

While using black seeds in small amounts in cooking can be a tasty way of incorporating the seeds in your diet, large-scale clinical trials are needed before the oil can be recommended as a treatment for any condition.

If you're still thinking of using black seed oil for health purposes, be sure to speak with your healthcare provider first to weigh the pros and cons and discuss whether it's right for you.