Blackseed is known by many names such as Nigella sativa, kalonji, and black cumin seed. The oil is extracted from the seeds of the Nigella sativa plant, which grows in the Mediterranean region and in southwest Asia.
While black seeds taste slightly bitter, it is used as a flavouring or spice in various dishes worldwide. Aside from its culinary purposes, the oil from black seed has the capacity to treat a wide range of medical maladies. Its medicinal properties are thought to be can be attributed to thymoquinone (TQ), a compound known to possess potent antioxidant properties.
Blackseed has a long history as a therapeutic option for a wide range of diseases.
In fact, the Assyrians in ancient Egypt used this beneficial herb for the treatment of gastrointestinal problems, skin diseases, and various inflammatory conditions.
Interestingly, black seed oil was found in the tomb of the Egyptian Pharaoh Tutankhamen, suggesting that it was used by the elite people of ancient Egypt. In biblical times, it was referred to as "curative black cumin." The great Greek physicians Hippocrates and Dioscorides also described black seed as "Melanthion" while the Romans called it “Greek Coriander.”
Health Benefits of Black Seed Oil
There is a large body of evidence suggesting that the health benefits of black seed oil can be attributed to its potent anti-inflammatory and antioxidant properties.
1. Improves Arthritis Symptoms
Blackseed oil can help provide long-lasting pain relief in people with arthritis. A study of patients with rheumatoid arthritis found that the group who took black seed oil 500mg twice daily for 1 month had a significant improvement in the number of swollen joints and the duration of morning stiffness, compared with the placebo-controlled group. 
In a similar study of patients with rheumatoid arthritis, it was found that the group who received 1000mg black seed oil daily for 8 weeks had lower blood levels of malondialdehyde (a marker of oxidative stress and inflammation) compared with control subjects. 
In a study of elderly patients with knee osteoarthritis, it was found that topical application of black seed oil rubbed into the affected knee joint every 8 hours for 3 weeks provided greater relief than the control group taking acetaminophen. 
2. Improves Cholesterol Levels
Blackseed oil can also help bring down cholesterol levels.
A recent review of several studies found that black seed oil has a greater effect in reducing total cholesterol, low-density lipoprotein (bad cholesterol), and triglyceride levels than black seed powder. 
A study of type 2 diabetic patients found that the group who consumed black seed oil at 2 grams per day had a significant decline in total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels, and a significant elevation in high-density lipoprotein (good cholesterol) levels compared with the group who took black seed oil at 1 gram per day and the group who consumed black seed oil at 3 grams per day. 
3. Reduces High Blood Pressure
Supplementation with black seed oil can benefit people with hypertension.
In a study of healthy volunteers, a significant reduction in systolic and diastolic blood pressure was observed in the group treated with 2.5 ml blackseed oil for 8 weeks compared with the placebo-treated group.
A study assessing the effects of black seed oil in patients with mild hypertension found that 100mg and 200 mg doses were effective at reducing systolic and diastolic blood pressure compared with placebo. 
4. Promotes Healthy Skin
Evidence suggests that black seed oil can help treat various skin conditions.
In a study of patients with vitiligo, a skin condition characterized by loss of skin colour in patches, it was found that skin application of black seed oil reduced more skin lesions than fish oil. 
In a rat model of psoriasis, skin application of black seed oil strongly inhibited psoriasis-like inflammation and skin changes induced by the drug imiquimod. 
5. Fights Diabetes
The anti-diabetic effect of black seed oil is also backed by a number of studies.
A 2019 review published in the International Journal of Environmental Research and Public Health found that black seed oil significantly improved laboratory parameters of hyperglycemia (high blood sugar levels) and diabetes control. 
In a study investigating the effects of black seed in patients with type 2 diabetes mellitus, it was found that consumption of black seed at a dose of 1, 2 and 3 g/day for three months significantly lowered blood sugar levels without any adverse effects. 
One review found that black seed oil can improve blood sugar levels in patients with type 2 diabetes mellitus through various important mechanisms, including its potent antioxidant properties and beneficial effects on insulin secretion and blood sugar absorption. 
Safety of Black Seed Oil
Black seed oil has been consumed for thousands of years and is a safe culinary ingredient. In larger doses, it may cause digestive upset in some people.
Black seed oil is not suitable to be used in pregnancy as more research is needed to determine its neonatal safety.
Black seed oil should be used in extreme caution in people with the following medical conditions. Always check with your GP if you have existing medical conditions or are taking medication.
Bleeding disorders: Black seed oil may interfere with the blood clotting ability of a person, thereby increasing the risk of bleeding if someone has a preexisting condition or is taking medication with a similar action such as warfarin.
Diabetes mellitus: While black seed oil can help bring down high blood sugar levels in diabetics, it should not be used together with blood-sugar-lowering medications as it may cause hypoglycemia (abnormally low blood sugar).
Hypotension(Low blood pressure): Black seed oil may cause abnormally low blood pressure in people with existing hypotension (low blood pressure). It should not be used in combination with anti-hypertensive medications as the combination may cause blood pressure to become too low.
Blackseed oil can also interact with the following medications:
Immunosuppressants: These medications work by decreasing the function of the immune system. A common example is corticosteroids. Taking black seed oil may decrease the effectiveness of immunosuppressants because of its immune-modulating properties.
Central nervous system depressants (sedative medications): Using black seed oil together with CNS depressants can increase the risk of respiratory depression.
How to Choose the Right Oil
To reap the full benefits of black seed oil, here are a few specific things to remember when choosing a product:
Choose an organic black seed oil. Organic products mean higher levels of antioxidants with no chemical fertilizer or pesticide residue. To ensure that organic products were used, look for a label that says “certified organic by the Soil Association”.
Cold Pressed .The method of preparation of black seed oil can have a significant impact on its potency. Specifically, most manufacturers of black seed products use heat to extract the oil. This method of extraction can damage thymoquinone and other beneficial compounds in black seed making it less effective.
Protective glass bottle. Aside from the method of preparation, the packaging can also affect the potency of black seed oil. It is highly recommended to opt for oil contained in an amber glass bottle to protect against ultraviolet rays from the sun. Oil should always be stored in glass as it can leach into the plastic.
1. GheitaTA, Kenawy SA. Effectiveness of Nigella sativa oil in the management of rheumatoid arthritis patients: a placebo-controlled study. Phytother Res.2012;26(8):1246-8.
2. HadiV, Kheirouri S, Alizadeh M, Khabbazi A, Hosseini H. Effects of Nigella Sativa oil extract on inflammatory cytokine response and oxidative stress status in patients with rheumatoid arthritis: a randomized, double-blind,placebo-controlled clinical trial. Avicenna J Phytomed. 2016;6(1):34–43.
3. KooshkiA, Forouzan R, Rakhshani MH, Mohammadi M. Effect of Topical Application of Nigella Sativa Oil and Oral Acetaminophen on Pain in Elderly with KneeOsteoarthritis: A Crossover Clinical Trial. Electron Physician.2016;8(11):3193–3197. Published 2016 Nov 25. DOI:10.19082/3193.
4. SahebkarA, Beccuti G, Simental-mendía LE, Nobili V, Bo S. Nigella sativa (black seed)effects on plasma lipid concentrations in humans: A systematic review and meta-analysis of randomized placebo-controlled trials. Pharmacol Res.2016;106:37-50.
5. KaatabiH, Bamosa AO, Lebda FM, Al Elq AH, Al-Sultan AI. The favourable impact of Nigellasativa seeds on lipid profile in type 2 diabetic patients. J Family CommunityMed. 2012;19(3):155–161. doi:10.4103/2230-8229.102311.
6. Fallahhuseini H, Amini M, Mohtashami R, et al. Blood pressure-lowering effect of Nigellasativa L. seed oil in healthy volunteers: a randomized, double-blind,placebo-controlled clinical trial. Phytother Res. 2013;27(12):1849-53.
7. DehkordiFR, Kamkhah AF. An antihypertensive effect of Nigella sativa seed extract in patients with mild hypertension. Fundam Clin Pharmacol. 2008;22(4):447-52.
8. GhorbanibirganiA, Khalili A, Rokhafrooz D. Comparing Nigella sativa Oil and Fish Oil in treatment of Vitiligo. Iran Red Crescent Med J. 2014;16(6):e4515.
9. OkashaEF, Bayomy NA, Abdelaziz EZ. Effect of Topical Application of Black Seed Oil on imiquimod-Induced Psoriasis-like Lesions in the Thin Skin of Adult Male albino rats. Anat Rec (Hoboken). 2018;301(1):166-174.
10. Hamdan A, Haji idrus R, Mokhtar MH. Effects of on Type-2 Diabetes Mellitus: ASystematic Review. Int J Environ Res Public Health. 2019;16(24).
11. BamosaAO, Kaatabi H, Lebdaa FM, Elq AM, Al-sultan b A. Effect of Nigella sativa seed son the glycemic control of patients with type 2 diabetes mellitus. Indian J Physiol Pharmacol. 2010;54(4):344-54.
12. HeshmatiJ, Namazi N. Effects of black seed (Nigella sativa) on metabolic parameters in diabetes mellitus: a systematic review. Complement Ther Med. 2015;23(2):275-82.
13. IkhsanM, Hiedayati N, Maeyama K, Nurwidya F. Nigella sativa as an anti-inflammatory agent in asthma. BMC Res Notes. 2018;11(1):744. Published 2018 Oct 19.doi:10.1186/s13104-018-3858-8.
14. KoshakA, Koshak E, Heinrich M. Medicinal benefits of Nigella sativa in bronchial asthma: A literature review. Saudi Pharm J. 2017;25(8):1130–1136.doi:10.1016/j.jsps.2017.07.002.
15. FarzanehE, Nia FR, Mehrtash M, Mirmoeini FS, Jalilvand M. The Effects of 8-week Nigellasativa Supplementation and Aerobic Training on Lipid Profile and VO2 max in Sedentary Overweight Females. Int J Prev Med. 2014;5(2):210–216.
16. Mahdavi R, Namazi N, Alizadeh M, Farajnia S. Effects of Nigella sativa oil with a low-calorie diet on cardiometabolic risk factors in obese women: a randomized controlled clinical trial. Food Funct. 2015;6(6):2041-8.
17. HuseiniHF, Kianbakht S, Mirshamsi MH, Zarch AB. Effectiveness of Topical Nigellasativa Seed Oil in the Treatment of Cyclic Mastalgia: A Randomized, Triple-Blind, Active, and Placebo-Controlled Clinical Trial. Planta Med.2016;82(4):285-8.
18. Shakeri F, Gholamnezhad Z, Mégarbane B, Rezaee R, Boskabady MH. Gastrointestinal effects of Nigella sativa and its main constituent, thymoquinone: a review.Avicenna J Phytomed. 2016;6(1):9–20.
19. Tavakkoli A, Mahdian V, Razavi BM, Hosseinzadeh H. Review on Clinical Trials of BlackSeed (Nigella sativa ) and Its Active Constituent, Thymoquinone. JPharmacopuncture. 2017;20(3):179-193.
20. SalariniaR, Rakhshandeh H, Oliaee D, Gul Ghasemi S, Ghorbani A. Safety evaluation ofPhytovagex, a pessary formulation of Nigella sativa, on pregnant rats. Avicenna J Phytomed. 2016;6(1):117–123.