What Is Black Seed Oil?

Black seed oil is extracted from the seeds of Nigella sativa, a plant native to southwest Asia. Some people use it for the treatment of certain health conditions, including:

• Asthma
• Diabetes
• Hypertension (high blood pressure)
• Weight loss

Black seed oil contains the antioxidant thymoquinone. Antioxidants detoxify harmful chemicals in the body called free radicals. These unstable molecules that the body produces in response to exposure to toxins can damage DNA and lead to cancer.

Black seed oil has a long history dating back over 2000 years. In fact, according to some sources, it was discovered in the tomb of King Tut. Nigella sativa seeds are sometimes used in Middle Eastern and Indian cuisine and have a slightly bitter taste. People also take it in supplement form.

There is scientific evidence to support some but not all uses for black seed oil. This article explains black seed oil uses, possible side effects, and preparation.

Black Seed Oil Uses

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

Rheumatoid Arthritis

According to a small study published in Immunological Investigations in 2016, black seed oil may treat rheumatoid arthritis.

For the study, 43 women with mild-to-moderate rheumatoid arthritis took black seed oil capsules or a placebo every day for one month. Compared to the placebo group, treatment with black seed oil reduced the following:

• Arthritis symptoms (as assessed by a clinical rating scale)
• Blood levels of inflammatory markers
• The number of swollen joints

Nasal Inflammation

Black seed oil shows promise for treating allergies. For instance, in a 2011 study published in the American Journal of Otolaryngology, when participants used black seed oil for two weeks, it reduced nasal symptoms, including:

• Nasal congestion
• Itchy nose
• Runny nose
• Sneezing

Another report published in 2018 analyzed data to determine if black seed oil could help treat sinusitis. Study authors concluded that the oil has multiple therapeutic effects, including:

• Anti-inflammatory
• Antioxidant
• Antihistaminic
• Immune-modulator
• Antimicrobial
• Analgesic

Diabetes

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

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

Another 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 2017 study published in Phytotherapy Research found that people with asthma who took black seed oil capsules significantly improved asthma control compared with those who took a placebo. Specific findings included:

• Improved mean asthma control test score by 21.1 for the black seed oil group and 19.6 for the placebo group
• Reduction in blood eosinophils (a type of white blood cell) by -50 cells/μL in the black seed oil group and 15 cells/μL in the placebo group
• Improved forced expiratory volume (how much air participants could exhale with a forced breath) in one second as a percentage of predicted value by four in the black seed oil group and one in the placebo group.

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, the following levels had decreased by more in the group that took the Nigella sativa oil:

• Weight
• Waist circumference
• Triglyceride

Another eight-week study sedentary women with excess weight combined aerobic exercise with black seed oil supplementation. In the study, one group took black seed oil, and another took a placebo; both used aerobic exercise.

Researchers found that this treatment combination provided benefits, including lower cholesterol levels and body mass index (BMI) compared to the placebo group. Still, the authors concluded that further studies with a larger sample size and diet assessment are needed.

Other Uses

Some people also use black seed oil as a remedy for other conditions, including:

• Allergies
• Headaches
• High blood pressure
• Digestive disorders

Proponents of black seed oil say its health benefits include:

• Boosting the immune system
• Reducing inflammation
• Fighting infections

People sometimes use the oil topically for skin and hair concerns, including:

• Acne
• Dry hair
• Psoriasis
• Hair growth
• Dry skin

Possible Side Effects

Very little is known about the long-term safety of black seed oil or how safe it is in amounts higher than what's typically found in food. However, some studies have found risks associated with black seed oil, including:

• Toxicity: A component of black seed oil known as melanthin may be toxic in larger amounts.
• Organ damage: There's some concern that taking too much black seed oil could harm the liver and kidneys.
• Allergic reaction: 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. However, she also ingested the oil, so it's possible that the blisters were part of a systemic reaction (such as toxic epidermal necrolysis).
• Bleeding risk: Black seed oil may slow blood clotting and increase the risk of bleeding. Therefore, if you have a bleeding disorder or take medication that affects blood clotting, you shouldn't take black seed oil. In addition, stop taking black seed oil at least two weeks before a scheduled surgery.
• Interaction with medications: It's also possible that black seed oil may interact with many common drugs, such as beta-blockers.

For these reasons, be sure to talk with your healthcare provider if you're considering taking black seed oil. In addition, remember that black seed oil is not a replacement for conventional medical care, so avoid stopping any of your medications without speaking with your healthcare provider.

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

Dosage and Preparation

There is not enough scientific evidence to establish a recommended dose for black seed oil. The right dose for you may depend on your age, health, and other factors, so it's essential to work with a qualified practitioner familiar with your circumstance.

Studies have examined various doses of black seed oil, including:

• For breast pain: In studies investigating the effects of black seed oil on people with breast pain, a gel containing 30% black seed oil was applied to the breasts every day for two menstrual cycles.
• For sperm function: 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.

What to Look For

You can purchase black seed oil in many places, including:

• Online
• Natural foods stores
• Stores specializing in dietary supplements

Dietary supplements are largely unregulated by the U.S. Food and Drug Administration (FDA). Therefore, it is illegal to market a dietary supplement product as a treatment or cure for a specific disease or claim that it will alleviate the symptoms of a disease. In addition, the FDA does not test products for safety or effectiveness.

So, when choosing an oil, keep the following in mind:

• Choose cold-pressed: Many consumers prefer to buy a product that is cold-pressed and organic to ensure 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.
• Look for certified products: 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 provide a certain level of testing for quality.

Summary

Some people use black seed oil supplements to treat certain health conditions, including arthritis, allergies, asthma, diabetes, and maintain a healthy weight. While some studies support health claims, most are small and more research is needed.

As a supplement, the FDA does not regulate black seed oil. So you should use caution and work with your healthcare provider to determine if it is right for you and at what dosage.