Black seed oil contains thymoquinone, which may support weight management, improve certain skin conditions, and help with wound healing, among other benefits.

However, it is important to note that there are few large, high-quality studies on black seed oil in humans. This makes it difficult to draw firm conclusions.

A person can use black seed oil topically or orally. Severe side affects are rare, though they may occur. This includes a possible allergic reaction.

In this article, we look at the science behind black seed oil’s benefits and explore the possible side effects and risks.

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Black seeds come from Nigella sativa, a small plant with pale purple, blue, or white flowers that grows in Eastern Europe, Western Asia, and the Middle East.

People have used the tiny black seeds of N. sativa fruits as a natural remedy for thousands of years. The seeds can also flavor curries, pickles, and bread. They are also known as black caraway, black cumin, kalonji, and black onion seeds.

Black seed oil contains thymoquinone, which is an antioxidant and anti-inflammatory compound. People can ingest black seed oil in the form of capsules or apply it topically to benefit the skin. It is also possible to add the oil to massage oils, shampoos, and homemade skincare products.

Scientists with a range of specialties have researched the possible benefits of black seed oil.

However, it is important to note that many studies to date have used cells or animals as models. There is limited research available on the effects of black seed oil in humans.

Weight management

A review of 11 studies has shown that black seed supplementation may help lower people’s body mass index (BMI) and waist circumference. The study participants did not report any severe side effects from taking this supplement.

A 2021 study on rats fed a high fat diet also found that black seed oil may be able to help significantly decrease body weight and insulin resistance.

However, in the review, there were a limited number of high-quality studies to examine, and the 2021 study involved animals rather than humans. More research is necessary to confirm these effects in humans.

Skin health

A 2022 review of previous studies found evidence that black seed oil may be helpful for managing a range of skin conditions due to its anti-inflammatory properties. These included:

  • eczema
  • psoriasis
  • acne
  • warts

However, the authors advise interpreting the results with caution, as there was some variation in the study results.

Wound healing

A 2017 review of past research notes there are animal and laboratory studies that suggest black seed oil may help with wound healing.

The exact science of how this works is not clear, but researchers theorize it may also be connected to the antioxidant and anti-inflammatory properties of thymoquinone. It is possible black seed oil may also increase collagen formation.


A 2022 study showed that has shown that the thymoquinone in black seed oil can stop cancerous cells from proliferating, and may also induce death in those cells.

A 2021 review and meta-analysis also found that thymoquinone may enhance the effects of chemotherapy and radiation treatments.

However, much of the research on the effects of black seed oil on cancer uses cells rather than live humans, so clinical trials are necessary to determine how it effects people.

Kidney health

Research from 2021 has suggests that black seed oil can have a protective effect on the kidneys.

There are several mechanisms by which this may work. In one of the key processes, thymoquinone appears to reduce the level of oxidative stress, which is an imbalance of free radicals and antioxidants in the body. It is also anti-inflammatory.

A 2019 study also shows that black seed oil may be helpful in reducing the size of kidney stones and eliminating kidney stones from the body.


An older 2016 meta-analysis found that black seed oil can help reduce high blood pressure.

In this analysis of 10 randomized controlled trials, administering the supplement showed a reduction in both the systolic and diastolic blood pressure among participants.

On the other hand, a 2017 clinical trial focusing on older adults with high blood pressure found that the reduction in blood pressure among participants who received the supplement was not significant when compared with the placebo group.

It is important to note that it is possible in some cases to experience low blood pressure as a result of using black seed oil. Speak with a doctor before using it to reduce blood pressure.


Black seed oil may have antidiabetic properties. A 2019 review of studies shows that the oil may help reduce a person’s blood glucose, hemoglobin, and insulin resistance.

This research suggests that it could be used as a treatment for type 2 diabetes along with conventional treatments.


An older 2014 clinical trial of males with infertility found that black seed oil may improve sperm movement, increase sperm count, and semen volume.

The findings of a more recent 2018 study on male mice confirm that the key ingredient thymoquinone can help boost the quality, motility, viability, and count of sperm cells. However, more research in humans is necessary to confirm these results.

Although black seed oil seems to offer certain health benefits, this supplement does not replace medication, and may cause drug interactions.

Thymoquinone may inhibit certain drug-metabolizing enzymes, making them less effective. For this reason, people should talk with a doctor before using any herbal supplement.

The doctor can advise on possible interactions, the potential benefits, and the side effects.

As with any supplement, pregnant or breastfeeding people should talk with a doctor to see if black seed oil is right for them before using it.

Serious side effects from black seed oil are rare. Taking it as an oral supplement may cause:

There is a case report from 2018 of three people who experienced a severe rash after applying black seed oil to the skin. Therefore, it is vital to test it on a small patch of skin first to ensure that it does not trigger a reaction. People must also take care to keep the oil away from the eyes, nostrils, and other sensitive body parts.

To get the safest black seed oil, always choose high quality, organic black seed oil that is 100% pure, therapeutic grade, and U.S. Department of Agriculture (USDA) certified.

The Food and Drug Administration (FDA) labels black seed oil as “Generally Recognized as Safe”. However, the FDA also does not test supplements for safety or effectiveness. For this reason, looking for a product from a reputable provider is important.

A person can search the database of the USDA for certified companies that produce or sell black seed oil. Other resources to find high quality products include ConsumerLabs, the U.S. Pharmacopeia, and NSF International.

The dosage a person should use may depend on the type of inflammation, condition, or issue they have. A person should speak with a doctor to make sure that using black seed oil is safe for them and to determine the right dose.

One 2021 study on the safe levels of the component of thymoquinone shows that adults should limit usage to a maximum of 900 milligrams (mg) of the oil or 48.6 mg of thymoquinone daily in order to reduce the risk of side effects.

People have used black seed oil for its therapeutic benefits for thousands of years.

Some studies have shown that it may have health and cosmetic benefits for various medical and skin conditions, although these studies often use animal or cell models rather than humans. More research into the effects of N. sativa in humans is necessary to confirm its benefits.

A person should always talk with a doctor before taking black seed oil and choose 100% pure, therapeutic grade, USDA-certified organic black seed oil.

The FDA does not monitor herbs and supplements for quality and purity, so it is vital to be selective when purchasing these products.