This article was previously published July 12, 2018, and has been updated with new information.
The use of medicinal plants to help treat various diseases is a practice that's as old as mankind. For example, the Egyptian medical book known as the Ebers Papyrus, written in 1550 B.C., details the use of 700 different plant species for therapeutic purposes. Mentioned plants include pomegranate, garlic, willow, coriander, juniper and onion. During the 7th century, Slavic people used cucumber, nettle and yarrow to help fight against various insect bites.1
Another example that has stood the test of time is black seed, which comes from the Nigella sativa (N. sativa) plant. In Indian Ayurveda and Unani traditional medicine, black seed figures greatly in their practice. For Muslims, black seed is known as the "Habbatul barakah" or the blessed seed. In fact, it is believed that the prophet Mohammed considered it to be a "remedy for all diseases except death."2 One of black seed's most popular applications is as an herbal oil.
There is sometimes some confusion between the terms "black cumin," "cumin," and "black seed," and there are instances when these are used interchangeably. But these are different plants. What makes it even more confusing is that black seed oil is sometimes called "black cumin seed oil." But "black cumin" actually refers to Bunium bulbocastanum, and is not same as black seed or the N. sativa plant.
While black seed oil has a long history of use, note that it has one downside worth pointing out — it contains linoleic acid (LA). As mentioned in my other articles, excess LA intake can raise metabolic concerns in the long run, especially with its prevalence in today’s food supply. That said, the research behind black seed oil entirely remains worth understanding because its bioactive compounds have demonstrated uses. The key is knowing how to approach it.
Potential Benefits of Black Seed Oil
Plenty of research has been conducted regarding the potential benefit of black seed oil. Here are some of the most notable ones:
• Helps fight fungal infections — In a study published in the International Journal of Health Sciences, researchers studied the cytoprotective effect of black seed oil in male rats. Results show that the group of rats treated with the oil showed reduced effects of AFB1 (aflatoxin-B1), a toxin produced by the Aspergillus flavus group of fungi.3,4
• Helps manage diabetes — In a study from Universiti Teknologi MARA in Malaysia, researchers tested the ability of black seed oil to manage diabetes in rats. They discovered that upon administration of the oil, all immunological parameters (serum glucose, Pan T- and B-lymphocytes and innate cell marker) were reduced while simultaneously increasing serum insulin levels.5
• Controls inflammation — Black seed oil contains anti-inflammatory compounds that may help manage certain conditions, an observation exhibited in a study published in the American Journal of Otolaryngology. Researchers noted that the oil was able to reduce the symptoms of allergic rhinitis in test subjects.6
• Helps reduce cancer risk — Various studies have been conducted regarding the potential anticancer benefits of black seed oil. Researchers have found that it may be helpful against these cancers:7
◦Colon
◦Pancreatic
◦Fibrosarcoma
Regular black seeds may also be helpful in preventing certain cancers. Studies have found that they may help reduce your risk of the following cancers:8
◦Liver
◦Lung
◦Breast
◦Blood
◦Cervical
• Promotes healthy blood pressure — N. sativa seeds have been traditionally used for helping relieve hypertension, and this hypothesis was tested out in a study published in Phytotherapy Research. In a double-blind, randomized experiment, results showed that test subjects who were treated with black seed oil showed a decrease in systolic and diastolic blood pressure compared to those who only took placebos.9
• Helps ease skin infections — Research has shown that N. sativa seeds contain strong antibacterial properties that may help fight Staphylococcus aureus, a common bacteria that can cause a variety of topical infections.10
Historical and Culinary Uses of Black Seed Oil
The N. sativa plant has been used for medicinal purposes for centuries. According to the Asian Pacific Journal of Tropical Biomedicine, its seeds and the oil were historically used to treat various disorders pertaining to the following areas:11
- Respiratory system
- Digestive tract
- Kidney function
- Liver health
- Cardiovascular system
- Immune system
Culinary uses of black seed oil include drizzling over salads and adding to juices or shakes. It’s sometimes taken on its own by the teaspoon. Because heat can damage its volatile compounds, it has typically been used unheated rather than cooked.12
Black seed oil has also been studied in respiratory contexts. A study published in the Saudi Pharmaceutical Journal notes that black seeds contain anti-inflammatory properties that showed promising results against asthma inflammation.13
The Composition of Black Seed Oil
Scientists have been able to isolate the various active compounds that make up black seed oil. Chief among them include:14
- Thymoquinone
- Thymohydroquinone
- Dithymoquinone
- P-cymene
- Carvacrol
- 4-terpineol
- T-anethol
- Sesquiterpene longifolene
- Thymol
Much of the research interest in black seed centers on thymoquinone (TQ), the primary bioactive compound in its volatile oil fraction. TQ makes up less than 1% of the total oil, but despite the minute amount, a study in Drug and Chemical Toxicology notes that it may be helpful in managing superoxide anions.15
In one study published in BMC Complementary and Alternative Medicine, TQ was tested against 11 human pathogenic bacteria strains. Researchers observed that TQ exhibited significant antibacterial activity, especially against Staphylococcus aureus ATCC 25923.16 In another study, TQ showed antifungal activity against the Candida albicans strain.17
Researchers have also examined TQ's effects on cancer cells. One study found that it induced growth inhibition and apoptosis in human osteosarcoma cells,18 while another reported cytotoxicity in human cervical squamous carcinoma cells.19
Potential Side Effects of Black Seed Oil
While black seed oil may potentially benefit your health, it is not without its own side effects. A study published in Phytotherapy Research notes that topical application caused contact dermatitis in two persons.20
The bigger concern, though, is its LA content. Black seed oil is 50% to 62% LA by weight. For context, LA is an omega-6 polyunsaturated fat (PUF) that your body needs in only small amounts. Consumed in excess, it can embed in your cell and mitochondrial membranes, where it can drive oxidative stress, impair energy production, and possibly contribute to the chronic metabolic dysfunction.
A single teaspoon of black seed oil delivers roughly 2.5 grams of LA, adding to a modern diet where LA already takes up between 15% and 25% of a typical American’s daily caloric intake. Because TQ makes up less than 1% of the oil, a standardized extract (5%, 10%, or 20%) can be a safer way to get the compound without the LA load. For a more in-depth explanation on this topic, read “Black Cumin Oil’s Benefits Come with a Linoleic Acid Tradeoff.”
Frequently Asked Questions About Black Seed Oil
Q: Does the linoleic acid content in black seed oil cause problems?
A: Yes. Black seed oil is 50% to 62% linoleic acid (LA) by weight, which means a single teaspoon delivers roughly 2.5 grams of LA — already past the 2 grams per day that better reflects what humans have historically consumed.
Since most modern diets are already overloaded with LA from seed oils and processed foods, adding black seed oil pushes intake further into a range associated with mitochondrial dysfunction, oxidative stress, and long-term metabolic harm. For those interested in thymoquinone, the compound behind black seed's researched benefits, standardized extracts deliver it without the LA load.
Q: What is black seed oil good for?
A: Based on numerous studies, black seed oil may help in various ways such as fighting microbes, managing inflammation promoting healthy blood pressure.
Q: Where can you buy black seed oil?
A: Black seed oil can be purchased online. However, what's more important is to thoroughly review the product you're buying and make sure it's made from high-quality ingredients by a reputable company.