Egypt or Ethiopia: the question arises as soon as you search for black seed oil. A 2024 study compared cold-pressed oils from Egyptian, Ethiopian, and Syrian seeds: thymoquinone, the most studied compound in black seed, represented 34.8% of the volatile fraction of Ethiopian oil, compared to 27.4% for Egyptian oil. But ten oils sold in the same country showed differences of 1 to 27 between them, and 64 Ethiopian varieties varied almost threefold in their essential oil.
This guide brings together what studies identified via PubMed show: what we really know about differences between origins, the impact of batch, pressing, heat, light and time, the benefits and limitations of oil in bottles, capsules and powder form, what matters according to clinical trials, and how to read a label.
Origin : only one study identified via PubMed directly compares oils from Egypt and Ethiopia. On a batch from each origin, the Ethiopian sample showed a higher proportion of thymoquinone in its volatile fraction, more polyphenols and vitamin E, and resisted oxidation better; Egyptian oil inhibited certain fungi more effectively in the laboratory. Fatty acids were nearly identical. No human trials compared the two origins.
What matters : variety, seed maturity, extraction, heat, light and storage duration vary the composition, and thymoquinone in commercial products ranges from 1 to 27. Trials used 200 mg to 4.6 g per day, 1 to 3 g in several trials cited here, in oil or powder form: trials varied the dose and duration, never the origin.
- Egypt, Ethiopia: the same plant, different oils
- The only study comparing Egypt and Ethiopia
- Within the same country, significant differences
- Commercial oils: a difference of 1 to 27
- Cold pressing, heat, extraction: what changes in production
- Light, heat and time: storage
- Oil, capsules or powder: advantages and limitations
- What really matters according to trials: dose and consistency
- Reading a black seed oil label
- Our two oils, side by side
- Frequently asked questions
Egypt, Ethiopia: the same plant, different oils
Whether it comes from Egypt, Ethiopia, Syria or India, black seed oil is derived from the seeds of the same plant, Nigella sativa. These are batches cultivated in different regions, from different local varieties, under different climates: it is this combination, more than the country's name, that varies the composition.
Pressed oil, called fixed oil, is first and foremost an oil rich in unsaturated fatty acids, especially linoleic acid. It also contains a small volatile, aromatic fraction, in which we find thymoquinone, p-cymene, carvacrol or alpha-thujene. Thymoquinone is the most studied compound of black seed, the one often used as a quality benchmark, as detailed in our article on black seed thymoquinone.
The composition is determined at the plant level. According to a study conducted in Israel, these aromatic compounds accumulate almost exclusively in the seed coat, and their profile evolves during maturation: alpha-thujene and gamma-terpinene, dominant in immature seeds, are progressively replaced by p-cymene, carvacrol, thymohydroquinone and thymoquinone. A seed harvested too early does not produce the same oil as a mature seed, regardless of its origin.
An Austrian analysis compared the essential oil of six seed samples and one commercial oil: the compounds were almost identical everywhere, and the differences related mainly to their proportions. This is the heart of the Egypt or Ethiopia question: different dosages of the same molecules.
Thymoquinone is expressed in two ways in studies. As a percentage of the volatile fraction (or essential oil), values of approximately 15 to 42% are obtained. As a percentage of the total weight of the oil, values measured in commercial oils range from less than 0.1% to nearly 2%. Both figures are correct, but they cannot be compared to each other.
The only study comparing Egypt and Ethiopia
Among studies indexed in PubMed, only one directly compares oils from Egypt and Ethiopia. Published in 2024 by an Egyptian-Polish team, it analyzed three cold-pressed oils, Egyptian, Ethiopian and Syrian, supplied by the same exporting company. According to the authors, nothing had yet been published on the volatile fraction of Ethiopian oil.
On three bottles of each origin, Ethiopian oil presented the highest share of thymoquinone in its volatile fraction (34.8%), ahead of Egyptian (27.4%) and Syrian (22.6%). It also contained the most polyphenols, flavonoids, phytosterols and vitamin E, and resisted oxidation longest under accelerated conditions. Fatty acids and triglycerides were similar in all three oils. In the laboratory, Ethiopian oil most inhibited the bacteria tested, Egyptian oil most inhibited the fungi producing aflatoxins.
Abdel-Razek AG, Hassanein MMM, Moawad S, et al. Molecules 2024;29(21):4985. DOI: 10.3390/molecules29214985
| Measured parameter | Egyptian oil | Ethiopian oil |
|---|---|---|
| Thymoquinone, share of the volatile fraction | 27.4% | 34.8% |
| Total polyphenols | 127.17 µg gallic acid equivalent per gram | 163.50 µg gallic acid equivalent per gram |
| Vitamin E and related compounds (tocopherols and tocotrienols) | 26.13 mg per 100 g | 40.35 mg per 100 g |
| Plant sterols | 1.84 mg per gram | 2.88 mg per gram |
| Resistance to oxidation, accelerated test at 120 °C | 2.5 hours | 7.89 hours |
| Fatty acids | Linoleic 61 to 62%, oleic 21 to 22%, palmitic 12% | Similar profile |
| Laboratory activity | Strongest against tested fungi; aflatoxin reduction close to Ethiopian oil | Strongest against tested bacteria |
These results are real, but their scope is limited. Each origin is represented by a single commercial batch, from a single supplier: it says nothing about other harvests or other producers in the same country. For volatile compounds, the authors mention possible effects of genetics, season, or variety—factors that vary from one batch to another. And antimicrobial activities were measured in culture dishes, not in the body.
This study therefore does not show that all Ethiopian oil would be richer than Egyptian oil, much less that it would have greater effects on health: no clinical trial has compared the two origins. None of these analyses covered our oils: these figures apply neither to our Ethiopian oil nor to our Egyptian capsules.
Within the same country, significant variations
Ethiopia has cultivated black seed for approximately 3,000 years, in several regions, using many local varieties. Ethiopian researchers have analyzed this diversity in detail, and their results put into perspective any idea of a single "Ethiopian oil."
In the essential oil of 64 black seeds cultivated in Ethiopia, 8 improved varieties and 56 local varieties, thymoquinone ranged from 14.81% to 42.44% depending on the variety, with an average of 31.08%, and p-cymene from 23.93% to 45.61%. The two compounds evolved in opposite directions: the more p-cymene a variety contained, the less thymoquinone it contained. The varieties split into two profiles, 56 rich in thymoquinone and 8 dominated by p-cymene.
Degu B, Tesfaye B, Abebe W, Assefa K. Biochem Res Int 2025;2025:2065593. DOI: 10.1155/bri/2065593
From one Ethiopian variety to another, the proportion of thymoquinone thus varies by nearly threefold; these values, obtained by distillation, are not directly comparable to those of the previous study. On the same 64 varieties, cultivated at two sites in 2021, an Ethiopian team also measured significant differences in oil yield per hectare. These analyses concern an essential oil obtained by distillation, not the pressed oil sold in bottles: they describe the diversity of the seeds.
Origin indicates a genetic and climatic starting point; it does not guarantee the composition of a given bottle.
Commercial oils: a range of 1 to 27
Two teams purchased commercial black seed oils and measured their thymoquinone by liquid chromatography.
In ten black seed oils sold in Malaysia, in bottles or capsules, thymoquinone ranged from 0.07% to 1.88% of the oil's weight, a difference of approximately 27 times. Bottles ranged from 0.14% to 1.88%, capsules from 0.07% to 1.86%: content was not related to packaging. The five products labeled "cold-pressed" were distributed across the entire range, from 0.07% to 1.88%.
Alkhatib H, Mawazi SM, Al-Mahmood SMA, et al. J Pharm Bioallied Sci 2020;12(3):284-288. DOI: 10.4103/jpbs.JPBS_208_20
A German team conducted the same exercise on the Swiss market, with six oils in bottles and five capsule products: from 3.08 to 809.4 mg of thymoquinone per 100 g, or at most approximately 0.8% of the oil's weight, with a gap close to 18 times for bottles and 31 times for capsules. All oils analyzed, except one Indian, were of Egyptian origin: the same origin produced oils that were both very poor and very rich.
The poorest product in this analysis was a batch of capsules analyzed six months after its expiration date: the authors see this as a possible explanation. And a capsule filled with the same oil as a bottle showed a similar content: it is the oil that determines the content, not the capsule. The authors recommend that thymoquinone content be listed on all products.
An electrochemical method published in 2026, tested on commercial oils and supplements, yielded results consistent with the contents declared by the manufacturers of the analyzed products: a displayed figure can therefore be verified.
Cold pressing, heat, extraction: what manufacturing changes
Cold pressing is the traditional method: the seeds are crushed mechanically, without solvent or intentional heating. In a Lithuanian study, it extracted 26.88% of the weight of untreated Egyptian seeds. Its yield is lower than industrial processes, but it uses no solvent, which explains consumer preference.
Regarding thymoquinone content, cold pressing is not always the richest method. A Malaysian team compared, on the same seeds, cold pressing and supercritical carbon dioxide extraction: 1.56 mg of thymoquinone per milliliter of cold-pressed oil, versus 6.63 mg with the supercritical process, and 94.40 versus 160.51 mg of polyphenols per 100 ml. These figures apply to this batch and these settings: they do not say that all cold-pressed oil would be poor, but that the extraction method matters.
Heat heat gives contradictory results. In a Korean study, roasting the seeds decreased the oil's thymoquinone. In a Turkish study, it reduced thymoquinone in their volatile fraction and produced roasting compounds. Conversely, an Israeli team obtained more thymoquinone by heating the seeds between 50 and 150 °C, and neither increased thymoquinone nor effects on these cells at 200 or 250 °C; its activity measurements were conducted on mouse cells.
Filtered or unfiltered? No identified study directly compared their thymoquinone content. In the Lithuanian study, conducted on unfiltered oil, the authors attribute, without having demonstrated it, an increase in oxidation resistance after four months to compounds released by the sediment. Practical tip: slight sediment at the bottom of an unfiltered oil bottle is expected.
| Factor | What studies show | Source |
|---|---|---|
| Country of origin | Real variations between an Egyptian batch and an Ethiopian batch, similar fatty acids | Abdel-Razek, 2024 |
| Cultivated variety | Thymoquinone from 14.81 to 42.44% of essential oil depending on variety, in Ethiopia | Degu, 2025 |
| Seed maturity | Thymoquinone progressively replaces other compounds as ripening occurs | Botnick, 2012 |
| Extraction process | 6.63 mg per milliliter in supercritical versus 1.56 mg in cold pressing, on the same batch | Mohammed, 2016 |
| Seed heating | Decrease with roasting in two studies, increase between 50 and 150 °C in a third | Kiralan, 2012; Agbaria, 2015; Mashhadi Abolghasem, 2023 |
| Oil storage | Acidity +65% and polyphenols declining in 4 months at 4 °C | Tarasevičienė, 2023 |
| Commercial products | Thymoquinone from 0.07 to 1.88% of oil weight, with no link to packaging | Alkhatib, 2020 |
Light, heat and time: storage
Black seed oil contains approximately 60% linoleic acid, a polyunsaturated fatty acid sensitive to oxidation. Like any oil of this type, it evolves after opening, and even before, between pressing and the table.
A cold-pressed black seed oil from Egyptian seeds, unfiltered, stored in a dark bottle at 4 °C, saw its acidity rise from 10.26% to 16.96% in four months, an increase of 65.40%. Its polyphenols dropped from 140.19 to 107.96 mg per 100 g, its resistance to oxidation fell by 74.11% after two months, and its aromatic profile had noticeably changed by four months.
Tarasevičienė Ž, Laukagalis V, Paulauskienė A, et al. Plants 2023;12(6):1351. DOI: 10.3390/plants12061351
Other studies nuance this picture. In a 2025 Turkish study, the proportion of thymoquinone remained constant during storage, but storage temperature changed oil quality, and oil kept at −80 °C showed the best resistance to oxidation. Pure thymoquinone, however, is very sensitive to light: in aqueous solution, brief exposure was enough to degrade it significantly. This result concerns the isolated molecule in water, not the oil, but it aligns with all research teams: opaque bottle, protected from light and heat.
In the 2024 comparative study, Ethiopian oil lasted 7.89 hours in the accelerated oxidation test, compared to 2.5 hours for Egyptian oil, a difference the authors possibly attribute to its volatile compounds, polyphenols and tocopherols. This is a laboratory result on one batch; in practice, the pressing date and storage conditions matter for all oils, regardless of their origin.
Reseal the bottle after each use, keep it away from light and heat, ideally in the refrigerator after opening, and use it within the following months. A rancid or very acrid smell, different from the usual odor, signals oxidized oil. These are practical storage tips, not results from clinical studies.
Oil, capsules or powder: advantages and limitations
Three forms dominate: oil in a bottle, oil in capsules, and whole or ground seed as powder. As for composition, as we've seen, oil in capsules is neither better nor worse than oil in a bottle: in the Malaysian analysis, thymoquinone content was not related to packaging, and in the Swiss analysis, a capsule filled with oil from a bottle had content close to it. The difference mainly comes down to ease of use.
As for effects, meta-analyses of clinical trials compared oil and seed powder, with results varying depending on the parameter measured:
Cholesterol : in a meta-analysis of 17 randomized placebo-controlled trials, black seed reduced total cholesterol by 15.65 mg/dL, LDL by 14.10 mg/dL, and triglycerides by 20.64 mg/dL on average. Oil had a more pronounced effect than powder on total cholesterol and LDL, while an HDL increase appeared only with powder.
Triglycerides in people with diabetes : a meta-analysis of 7 trials found a decrease of 14.8 mg/dL with oil, but an increase of 29.4 mg/dL with powder, based on a small number of studies.
Blood glucose : in a meta-analysis of 17 randomized trials, fasting blood glucose decreased by 9.93 mg/dL on average, and oil proved more effective than powder on this parameter.
Blood pressure : conversely, in a meta-analysis of 11 trials and 860 people, the average decrease was 3.26 mmHg for systolic pressure and 2.80 mmHg for diastolic, and the powder preparation subgroup showed the most marked effect. The authors found no link between systolic decrease and preparation type in their regression analysis, however: the difference between forms remains uncertain, with moderate heterogeneity between trials (I² of 59 and 60%).
These comparisons are based on different trials, with different doses and durations: these are trends, not direct face-offs. No form has proven general superiority. Powder also has culinary interest, as explained in our guide for consuming black seeds, and our organic black seed powder is made from ground organic seeds.
| Form | Strengths | Limitations |
|---|---|---|
| Oil in a bottle | Adjustable dose by spoon, use in cooking and for skin or scalp application, more pronounced effect than powder on total cholesterol, LDL and fasting blood glucose in meta-analyses | Distinct black seed flavor, bottle must be protected from light and heat, oxidation after opening |
| Oil in capsules | Flavorless, fixed dose easy to reproduce from day to day, quick intake | Lower quantity of oil per dose, no external use, variable content from one product to another as with bottles |
| Ground seed powder | Whole seed, with its fiber and protein, easy to incorporate into meals, used in several trials at 1 to 3 g per day | Must be stored tightly sealed, air, heat and light affecting volatile compounds; distinct flavor; different results from oil depending on the parameters |
What really matters according to trials: dose and regularity
No clinical trial specifies the geographical origin of the oil or powder as a factor of efficacy, and none compared Egyptian oil to Ethiopian oil. What the trials vary, and what emerges from their analyses, is the dose and the duration.
In 94 people with type 2 diabetes, capsules of black seed at 1, 2, or 3 g per day for 12 weeks were compared. At 2 g per day, total cholesterol, triglycerides, and LDL decreased significantly; at 1 g per day, changes were not significant; increasing to 3 g provided no additional benefit over 2 g.
Kaatabi H, Bamosa AO, Lebda FM, et al. J Family Community Med 2012;19(3):155-161. DOI: 10.4103/2230-8229.102311
The same team then followed 114 people with diabetes under treatment for one year, with 2 g of seeds per day or placebo: glycated hemoglobin decreased from 8.6 to 8.2% under black seed, and from 8.2 to 8.5% under placebo, in groups formed without randomization. Black seed complemented treatment there, never replacing it, as reminded in our article on elevated blood sugar.
The subgroups of recent meta-analyses provide signals on dose and duration, not always in the same direction. In 16 trials in people with type 2 diabetes, fasting blood glucose decreased especially beyond 8 weeks, and glycated hemoglobin, HOMA index, and LDL more above 1 g per day, with oil and, unexpectedly, over 8 weeks or less. In 11 trials, insulin resistance decreased in the subgroup followed for more than 8 weeks, and body mass index in that dosed above 1 g per day. The largest synthesis brings together 82 studies and 5,026 participants, with 200 to 4,600 mg per day for 1 to 48 weeks.
In a randomized double-blind trial, 80 asthmatic people took 500 mg of black seed oil in capsules twice daily, or 1 g per day, for 4 weeks, in addition to their treatment: their asthma control score was 21.1 versus 19.6 under placebo, with no significant difference in measured lung function. Our capsules of black seed oil from Egypt provide the same quantity of oil, 1 g per day in two capsules; the oil in that trial was not ours, and no trial has tested our products.
These effects remain modest. A 2026 meta-analysis of 31 trials and 2,145 participants reports modest improvements, including 1.59 kg less weight and 3.25 mmHg less systolic pressure, to be interpreted with caution given the variable quality of studies. In another, over 30 trials, heterogeneity exceeded 90% for blood glucose. Many trials are small, short, and conducted in a few countries.
In the trials cited here, black seed was taken daily, for 4 weeks to one year, at doses of 1 to 3 g of oil or powder. Occasional or irregular intake was not studied. The choice between Egypt and Ethiopia, meanwhile, has never been evaluated in humans.
Reading a black seed oil label
Without a study to distinguish origins, the label remains your best tool. Here are the benchmarks that can be drawn from the studies cited, presented as a practical method.
A percentage of isolated thymoquinone does not allow comparing two products: the method and calculation basis strongly change the figure.
Our two oils, side by side
We offer a Ethiopian black seed oil in a bottle and an Egyptian black seed oil in capsules. No study allows us to say that one would be more beneficial than the other for health, and no trial has tested our products: their difference lies in the format, usage, and taste.
| Characteristic | Ethiopian black seed oil | Egyptian black seed oil in capsules |
|---|---|---|
| Format | 100 ml bottle | Capsules |
| Process | Cold-pressed, unfiltered, 100% seed oil | Cold-pressed, with vitamin E |
| Quantity per day | 1 to 3 teaspoons | 2 capsules during meals, or 1 g of oil and 15 mg of vitamin E |
| Thymoquinone | Not documented by a cited study | Not indicated, not documented by a cited study |
| Taste | Black seed taste, unmasked | Tasteless |
| Uses | Internal, in cooking, and external on the scalp or skin | Internal only |
| Not recommended for | Children and pregnant women; medical advice during breastfeeding | Children, adolescents, pregnant or nursing women |
The oil in a bottle is suitable if you like to measure by teaspoon, cook with it, or apply it. The product sheet indicates one to three teaspoons per day, morning and evening, or in the morning on an empty stomach, in the afternoon and at bedtime; a few drops massaged on the scalp for at least 20 minutes or overnight, or on the skin 2 to 3 minutes before rinsing. These are usage recommendations, not trial results.
The capsules are suitable if you dislike the taste or are looking for a fixed dose: 1 g of oil per day in two capsules, the quantity from the 4-week trial described above, conducted on asthmatic individuals with a different oil. Their thymoquinone content is not indicated.
For either one, the thymoquinone content is not documented by any of the studies cited here. In both cases, consistency in intake and proper storage are practical reference points; no study has compared origins in humans, and precautions are the same.
Pregnancy, children : the oil and capsules are not recommended during pregnancy and in children, capsules also in adolescents and during breastfeeding; for oil in a bottle, medical advice is necessary during breastfeeding. Treatments : if taking anticoagulants, antidiabetics, antihypertensives or immunosuppressants, consult your doctor. A laboratory study showed that thymoquinone slows the enzyme that transforms warfarin, and, according to modeling based on these in vitro data, an interaction would be possible beyond 1 g of oil per day; this has not been demonstrated in humans, but caution is warranted. Skin : a case of contact eczema from nigella oil has been reported, with thymoquinone identified as the allergen responsible; practical advice: test the oil on a small area before widespread application. Our article on the risks of nigella oil details all precautions.
100% oil from Ethiopian nigella seeds, cold-pressed and unfiltered, in a 100 ml bottle. One to three teaspoons per day, in cooking or plain, and a few drops for the scalp or skin: an oil for both internal and external use.
See Ethiopian nigella oilOur complete guide to nigella oil reviews its documented benefits, study by study.
Frequently asked questions
Egyptian or Ethiopian nigella oil: which one to choose?
No study can identify a better origin for health, as no human trials have compared them. A 2024 analysis, conducted on a batch from each country, found in the Ethiopian sample a higher proportion of thymoquinone in the volatile fraction and more antioxidants, but other studies find large variations within the same country. The choice can be made based on format, taste, freshness and label clarity.
Does Ethiopian nigella oil contain more thymoquinone?
The only comparative study does not allow us to say: it measured the proportion of thymoquinone in the volatile fraction, higher for the Ethiopian sample (34.8% versus 27.4%), not its content in the oil. But among 64 Ethiopian varieties, thymoquinone ranged from 14.81 to 42.44% of the essential oil. Origin does not guarantee the content of a given bottle.
What is the difference between Egyptian and Ethiopian nigella oil?
Both come from the same plant, Nigella sativa. In the 2024 comparative study, their fatty acids were similar, with 61 to 62% linoleic acid; the Ethiopian sample had a higher proportion of thymoquinone in its volatile fraction, and more polyphenols, tocopherols and tocotrienols; it resisted oxidation better, and the Egyptian sample inhibited certain fungi more effectively in the laboratory. These differences are based on one batch per country.
What is the best nigella oil?
Studies do not identify a better origin. They do show what causes quality to vary: the variety and maturity of seeds, the extraction process, heat, light and storage duration. A Nigella sativa oil alone, cold-pressed, in an opaque bottle, with a distant expiration date and, if possible, a thymoquinone content indicated with its method, combines useful benchmarks.
How do you know if nigella oil is of good quality?
Check for Nigella sativa species and absence of other oils, cold-pressing process, an opaque bottle or capsules, and a distant best-before date. A rancid smell indicates oxidized oil. The thymoquinone content, when listed, is useful if you know how it was calculated. In an analysis of ten products, the cold-pressed label ranged from 0.07 to 1.88% thymoquinone.
Should you choose cold-pressed nigella oil?
Cold-pressing extracts oil without solvent and without intentional heating, which explains consumer preference. It does not alone ensure a high thymoquinone content: on the same batch, supercritical extraction yielded 6.63 mg of thymoquinone per milliliter versus 1.56 mg for cold-pressing. It is a process benchmark, to be supplemented by freshness and storage.
Filtered or unfiltered oil: what's the difference?
No identified study has directly compared their thymoquinone content. Practical advice: unfiltered oil retains a slight sediment, which simply requires gentle stirring. In a storage study on cold-pressed unfiltered oil, the authors suggest that this sediment released compounds that increased its resistance to oxidation after four months.
Nigella oil in capsules or in a bottle: what to choose?
In terms of composition, thymoquinone content was not linked to packaging in an analysis of ten products, and a capsule filled with oil from a bottle had similar content. The bottle allows dosing by teaspoon, cooking and applying the oil; capsules are tasteless and provide a fixed dose, such as 500 mg twice daily in a 4-week trial.
Nigella oil or powder: which form is most effective?
No form is superior in all areas. In meta-analyses, oil had a more marked effect on total cholesterol, LDL and fasting blood sugar, powder on HDL and, in one analysis, on blood pressure. These comparisons are based on different trials and remain trends.
How to store nigella oil?
Well sealed, away from light and heat, ideally in the refrigerator after opening, and used in the following months. In one study, cold-pressed oil stored in the refrigerator saw its acidity increase by 65% and its polyphenols decline over four months, and pure thymoquinone degrades quickly in light.
What dose of nigella oil was used in the studies?
According to a synthesis of 82 studies, trials used 200 mg to 4.6 g per day, for 1 to 48 weeks; several trials cited here involved 1 to 3 g. In a trial of three doses of seeds in people with diabetes, 2 g per day performed better than 1 g, and 3 g provided no additional benefit. In a meta-analysis, the reduction in fasting blood sugar appeared mainly in trials lasting more than 8 weeks.
Sources
The studies cited below were identified via PubMed.
- Abdel-Razek AG, Hassanein MMM, Moawad S, et al. Evaluation of quality, bioactive compounds and antimicrobial activity of Egyptian, Ethiopian and Syrian black seed oils. Molecules, 2024;29(21):4985. DOI
- Alkhatib H, Mawazi SM, Al-Mahmood SMA, et al. Thymoquinone content of black seed oils commercialized in Malaysia. Journal of Pharmacy and Bioallied Sciences, 2020;12(3):284-288. DOI
- Degu B, Tesfaye B, Abebe W, Assefa K. Diversity of Ethiopian black seed according to its essential oil composition. Biochemistry Research International, 2025;2025:2065593. DOI
- Botnick I, Xue W, Bar E, et al. Distribution of primary and specialized metabolites in Nigella sativa seeds, a spice with extensive traditional and historical uses. Molecules, 2012;17(9):10159-10177. DOI
- Burits M, Bucar F. Antioxidant activity of Nigella sativa essential oil. Phytotherapy Research, 2000;14(5):323-328. DOI
- Gebremedin BD, Asfaw BT, Mengesha WA, Abebe KA. Biochemical characterization of Ethiopian black seed. International Journal of Food Science, 2024;2024:2746560. DOI
- Khaikin E, Chrubasik-Hausmann S, Kaya S, Zimmermann BF. Assay of thymoquinone in commercial Nigella sativa-based products to identify a promising and safe study product. Nutrients, 2022;14(17):3501. DOI
- Świderski M, Mirceski V, Guziejewski D, et al. Sustainable and label-free voltammetric assay of thymoquinone in food products based on Nigella sativa oil. Food Chemistry, 2026;508(Pt B):148442. DOI
- Tarasevičienė Ž, Laukagalis V, Paulauskienė A, et al. Evolution of quality of cold-pressed black seed, safflower and milk thistle oils during storage. Plants, 2023;12(6):1351. DOI
- Mohammed NK, Abd Manap MY, Tan CP, et al. Effects of different extraction methods on the antioxidant properties, chemical composition and thermal behavior of black seed oil. Evidence-Based Complementary and Alternative Medicine, 2016;2016:6273817. DOI
- Mashhadi Abolghasem F, Kim RH, Park SY, et al. Effects of roasting and ultrasound-assisted enzymatic treatment of Nigella sativa seeds on thymoquinone oil content and antioxidant activity of defatted meal. Journal of the Science of Food and Agriculture, 2023;103(13):6208-6218. DOI
- Kiralan M. Volatile compounds of microwave-heated and conventionally roasted nigella seeds. Journal of Food Science, 2012;77(4):C481-C484. DOI
- Agbaria R, Gabarin A, Dahan A, Ben-Shabat S. Anticancer activity of Nigella sativa and its relationship with heat treatment and seed quinone composition. Drug Design, Development and Therapy, 2015;9:3119-3124. DOI
- Doğan S, Özek T, Aytar Çelik P. Effects of different extraction conditions and storage on nigella seed oil. Food Chemistry, 2025;496(Pt 1):146701. DOI
- Salmani JMM, Asghar S, Lv H, Zhou J. Aqueous solubility and degradation kinetics of thymoquinone: effects of solvents, pH and light. Molecules, 2014;19(5):5925-5939. DOI
- Sahebkar A, Beccuti G, Simental-Mendía LE, et al. Effects of Nigella sativa on blood lipids in humans: systematic review and meta-analysis of randomized placebo-controlled trials. Pharmacological Research, 2016;106:37-50. DOI
- Daryabeygi-Khotbehsara R, Golzarand M, Ghaffari MP, Djafarian K. Nigella sativa improves glycemic balance and blood lipids in type 2 diabetes: systematic review and meta-analysis. Complementary Therapies in Medicine, 2017;35:6-13. DOI
- Askari G, Rouhani MH, Ghaedi E, et al. Effect of Nigella sativa supplementation on glycemic control: systematic review and meta-analysis of clinical trials. Phytotherapy Research, 2019;33(5):1341-1352. DOI
- Sahebkar A, Soranna D, Liu X, et al. Systematic review and meta-analysis of randomized trials on the effects of Nigella sativa supplementation on blood pressure. Journal of Hypertension, 2016;34(11):2127-2135. DOI
- Kaatabi H, Bamosa AO, Lebda FM, et al. Favorable effect of Nigella sativa seeds on the lipid profile of patients with type 2 diabetes. Journal of Family and Community Medicine, 2012;19(3):155-161. DOI
- Kaatabi H, Bamosa AO, Badar A, et al. Nigella sativa improves glycemic control and reduces oxidative stress in patients with type 2 diabetes: a single-blind placebo-controlled clinical trial. PLoS One, 2015;10(2):e0113486. DOI
- Karimi M, Pirzad S, Pourfaraji SMA, et al. Effects of nigella on cardiometabolic indices in patients with type 2 diabetes: a systematic review and meta-analysis of randomized trials. Complementary Therapies in Medicine, 2025;90:103174. DOI
- Saadati S, Naseri K, Asbaghi O, et al. Nigella sativa supplementation improves cardiometabolic indicators in prediabetes and type 2 diabetes: a systematic review and meta-analysis of randomized trials. Frontiers in Nutrition, 2022;9:977756. DOI
- Jafari A, Mardani H, Faghfouri AH, et al. Does Nigella sativa supplementation improve cardiovascular risk factors? A systematic review and dose-response meta-analysis of 82 randomized trials. Pharmacological Research, 2025;219:107882. DOI
- Koshak A, Wei L, Koshak E, et al. Nigella sativa supplementation improves asthma control and its markers: a double-blind placebo-controlled randomized trial. Phytotherapy Research, 2017;31(3):403-409. DOI
- Musazadeh V, Jahangir M, Mahmoudinezhad M, et al. Effect of Nigella sativa supplementation on cardiometabolic health in patients with metabolic diseases: a systematic review and meta-analysis. Endocrinology, Diabetes and Metabolism, 2026;9(2):e70207. DOI
- Shirvani S, Falahatzadeh M, Oveili E, et al. Effect of Nigella sativa supplementation on blood glucose in adults: an updated systematic review and meta-analysis of randomized trials. Prostaglandins and Other Lipid Mediators, 2024;174:106885. DOI
- Sumara A, Stachniuk A, Trzpil A, et al. Metabolomic profile by liquid chromatography and mass spectrometry of five cold-pressed unrefined seed oils to identify authenticity markers and detect fraud. Molecules, 2023;28(12):4754. DOI
- Wang Z, Wang Z, Wang X, et al. Potential risk of interaction between thymoquinone and warfarin. Chemico-Biological Interactions, 2022;365:110070. DOI
- Kurihara F, Soria A, Lepoittevin JP, et al. Thymoquinone, the allergen responsible for contact eczema from Nigella sativa oil, with cross-reactivity to tert-butylhydroquinone. Contact Dermatitis, 2020;83(2):132-134. DOI
