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Black seed oil

Pooled trials report lower total cholesterol, LDL, triglycerides, fasting glucose, HbA1c and blood pressure with Nigella sativa than control. Body weight fell about 1.8 kg, with high heterogeneity. Asthma evidence rests on 4 trials. Case reports describe kidney injury with muscle breakdown and a large bruise in a patient on antiplatelet drugs.

Add to Bio HackChecked 2026-11-09
Status
Dietary supplement and food spice in the US. Not approved by the FDA as a drug for any use.
Also called
Nigella sativa, black seed, black cumin, kalonji, black caraway, nigella, thymoquinone, habbatul barakah
Taken for
cholesterol, blood sugar, blood pressure, weight loss, asthma, inflammation, immunity, liver health

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help6

Reported risks3

What people take it for, and what was found

Shown to help6

Strong

Cholesterol and triglycerides

Shown to lower LDL by about 14 mg/dL and triglycerides by about 21 mg/dL in adults. HDL did not change overall.

The numbers and sources
Effect
In 17 RCTs, Nigella sativa lowered total cholesterol by 15.65 mg/dL (95% CI -24.67 to -6.63), LDL by 14.10 mg/dL and triglycerides by 20.64 mg/dL. HDL did not change overall (0.28 mg/dL, 95% CI -1.96 to 2.53) and rose only with seed powder. Oil lowered total and LDL cholesterol more than powder [1]. A 2025 review of 82 RCTs (5,026 participants) also reported improved total cholesterol, LDL, HDL and triglycerides [2].
Population
Adults in placebo-controlled RCTs [1]. Trials of 1 to 48 weeks [2].
Sources
[1], [2]
Caveats
The 2025 abstract lists outcomes without effect sizes [2]. Neither review measured heart attacks or strokes.
Strong

Blood sugar

Shown to lower fasting glucose by about 10 mg/dL and HbA1c by about 0.6 points in adults.

The numbers and sources
Effect
In 17 RCTs, fasting glucose fell 9.93 mg/dL (95% CI -13.44 to -6.41), post-meal glucose 14.79 mg/dL and HbA1c 0.57 percentage points (95% CI -0.77 to -0.37). Oil lowered fasting glucose more than powder [3]. The 2025 review also reported improved fasting glucose, HbA1c and post-meal glucose [2].
Population
Adults in clinical trials [2][3].
Sources
[3], [2]
Caveats
The authors call for longer, stronger trials [3].
Strong

Blood pressure

Shown to lower blood pressure by about 3 mmHg systolic and 3 mmHg diastolic over about 8 weeks in adults.

The numbers and sources
Effect
In 11 RCTs (860 people with or without hypertension), systolic pressure fell 3.26 mmHg (95% CI -5.10 to -1.42, I² 59%) and diastolic 2.80 mmHg (95% CI -4.28 to -1.32) more than control over a mean 8.3 weeks. Powder lowered pressure more than oil [4]. The 2025 review also reported lower systolic and diastolic pressure [2].
Population
Hypertensive and normotensive adults [2][4].
Sources
[4], [2]
Caveats
The 2016 review included English-language trials only [4].
Moderate

Body weight

Shown to lower weight by about 1.6 to 1.8 kg in adults, with very high variation. In type 2 diabetes, weight did not change significantly.

The numbers and sources
Effect
In 10 RCTs, weight fell 1.76 kg (95% CI -3.34 to -0.17, I² 87.4%) against placebo. BMI fell 0.85 kg/m² in 11 trials. Waist size did not change significantly in 5 trials (-4.04 cm, I² 97.8%) [5]. In 31 trials (2,145 people) with metabolic diseases, weight fell 1.59 kg (95% CI -3.03 to -0.15) and BMI 0.51 kg/m², with no change in waist or hip size [6]. In 16 RCTs in type 2 diabetes, body weight and BMI did not change significantly [7].
Population
875 adults, 64% male, in 13 RCTs [5]. Adults with type 2 diabetes, obesity or other metabolic diseases [6][7].
Sources
[5], [6], [7]
Caveats
Heterogeneity was very high [5]. The reviews disagree in type 2 diabetes [7]. The 2026 authors note variable study quality [6].
Limited

Asthma control

Limited evidence: 4 trials found better asthma control scores and lung function in people with asthma. Peak flow did not change.

The numbers and sources
Effect
In 4 RCTs, Nigella sativa raised asthma control test scores (SMD 0.50, 95% CI 0.11 to 0.88) and FEV1 (SMD 1.84, 95% CI 0.07 to 3.60). Peak flow, IL-4 and interferon gamma did not change significantly [8].
Population
People with asthma in 4 RCTs [8].
Sources
[8]
Caveats
Four trials, with a wide interval for FEV1.
LimitedStudied in women

Inflammation markers

One small trial found 1,000 mg a day lowered IL-6 in 60 women with PCOS. Trials of other inflammation markers conflicted.

The numbers and sources
Effect
In 60 women with polycystic ovary syndrome, 1,000 mg a day of oil for 12 weeks lowered serum IL-6 against placebo (adjusted mean difference -4.21, 95% CI -6.34 to -2.08) and fasting glucose by 8.16 mg/dL. Fasting insulin and HOMA-IR did not differ [9]. A review of 4 human trials found conflicting results for the adhesion molecules VCAM-1 and ICAM-1 [10].
Population
60 women with PCOS [9]. Patients with coronary artery disease, type 2 diabetes, Hashimoto's thyroiditis or cardiovascular risk factors [10].
Sources
[9], [10]
Caveats
One small trial for IL-6 [9]. The adhesion molecule review also included 15 animal and in vitro studies, which are not counted here [10].

Doses studied

Trials in the 2025 review used 200 to 4,600 mg a day for 1 to 48 weeks [2]. Blood pressure trials averaged 8.3 weeks [4]. In the liver and kidney review, 1,100 to 1,500 mg a day was the range linked to lower ALP, and more than 2,000 mg a day was linked to a BUN change [11]. A safety trial used 200 mg a day of a 5% thymoquinone oil for 90 days [12].

Risks

Reported risks2

LimitedHow often is not known

Kidney injury and muscle breakdown

Case reports: one person had acute kidney injury, muscle breakdown and liver toxicity after drinking black seed oil.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
A 2024 case report describes acute kidney injury, rhabdomyolysis and liver toxicity after a person drank black seed oil [14].
Population
One case [14].
Sources
[14]
Caveats
A single case report cannot give a rate.
LimitedHow often is not known

Bleeding with antiplatelet drugs and chemotherapy

Case reports: a man on antiplatelet drugs and chemotherapy developed a large hematoma at 2,000 mg a day of oil, which cleared after stopping.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
A 51-year-old man on dual antiplatelet therapy and oxaliplatin chemotherapy developed a large subcutaneous hematoma after his trial dose of Nigella sativa oil rose to 2,000 mg a day. His platelet count was 52 × 10³/µL. The hematoma resolved within 10 days after the suspected agents were stopped, and did not recur at 1,000 mg a day. The Naranjo score rated it a possible adverse drug reaction [15].
Population
One case in a clinical trial [15].
Sources
[15]
Caveats
He had several other bleeding risk factors [15].

Mixed results1

ModerateHow often is not known

Liver and kidney markers in trials

Liver and kidney markers did not worsen in most trials. Creatinine rose slightly in 3 trials, and doses above 2,000 mg a day were linked to a BUN change.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
In 19 trials (1,295 participants), Nigella sativa lowered ALP by 10.8 U/L and BUN by 1.016. Creatinine rose by 0.070 in 3 trials with covariate-adjusted analyses, and doses above 2,000 mg a day were linked to a BUN change in 2 trials [11]. In 70 healthy adults given 200 mg a day of a thymoquinone-rich oil for 90 days, liver and kidney tests did not change and no serious adverse effects were reported [12].
Population
Adults in RCTs [11]. 70 healthy adults [12].
Sources
[11], [12]
Caveats
The safety trial's corresponding author is at Akay Natural Ingredients, the maker of the tested oil [12]. Heterogeneity for ALP and BUN was high [11]. In 16 RCTs in type 2 diabetes, AST, ALT and creatinine did not change significantly [7].

Checked, no increase found1

ModerateStudied in children

Side effects in children

Side effects were not significantly more common, and none were severe, across 15 pediatric trials.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
A meta-analysis of 15 pediatric clinical trials found no statistically significant occurrence of side effects and no severe adverse effects [13].
Population
Children in trials for a range of conditions, with different doses and forms [13].
Sources
[13]
Caveats
The authors describe the pediatric studies as limited and call for more [13].

Claims tested and not found

  1. That Nigella sativa shrinks the waist. Waist circumference did not change significantly in 5 RCTs [5] or in a 31-trial meta-analysis in metabolic diseases [6].
  2. That Nigella sativa improves peak airflow in asthma. Peak expiratory flow did not change significantly in 4 RCTs [8].

Sources

  1. Sahebkar A, Beccuti G, Simental-Mendía LE, et al. Nigella sativa (black seed) effects on plasma lipid concentrations in humans: A systematic review and meta-analysis of randomized placebo-controlled trials. Pharmacological Research. 2016. https://doi.org/10.1016/j.phrs.2016.02.008
  2. Jafari A, Mardani H, Faghfouri AH, et al. Does Nigella sativa supplementation improve cardiovascular disease risk factors? A comprehensive GRADE-assessed systematic review and dose-response meta-analysis of 82 randomized controlled trials. Pharmacological Research. 2025. https://doi.org/10.1016/j.phrs.2025.107882
  3. Askari G, Rouhani MH, Ghaedi E, et al. Effect of Nigella sativa (black seed) supplementation on glycemic control: A systematic review and meta-analysis of clinical trials. Phytotherapy Research. 2019. https://doi.org/10.1002/ptr.6337
  4. Sahebkar A, Soranna D, Liu X, et al. A systematic review and meta-analysis of randomized controlled trials investigating the effects of supplementation with Nigella sativa (black seed) on blood pressure. Journal of Hypertension. 2016. https://doi.org/10.1097/HJH.0000000000001049
  5. Mousavi SM, Sheikhi A, Varkaneh HK, et al. Effect of Nigella sativa supplementation on obesity indices: A systematic review and meta-analysis of randomized controlled trials. Complementary Therapies in Medicine. 2018. https://doi.org/10.1016/j.ctim.2018.04.003
  6. Musazadeh V, Jahangir M, Mahmoudinezhad M, et al. The Effect of Nigella sativa Supplementation on Cardiometabolic Health in Patients With Metabolic Diseases: A GRADE-Assessed Systematic Review and Meta-Analysis. Endocrinology, Diabetes & Metabolism. 2026. https://doi.org/10.1002/edm2.70207
  7. Karimi M, Pirzad S, Pourfaraji SMA, et al. Effects of black seed (Nigella sativa L.) on cardiometabolic indices in type 2 diabetic patients: A systematic review and meta-analysis of RCTs. Complementary Therapies in Medicine. 2025. https://doi.org/10.1016/j.ctim.2025.103174
  8. He T, Xu X. The influence of Nigella sativa for asthma control: A meta-analysis. The American Journal of Emergency Medicine. 2020. https://doi.org/10.1016/j.ajem.2019.11.036
  9. Jamshidian S, Jalilvand F. Nigella sativa (Black Seed) Oil Alleviates the Serum Levels of IL-6 and Insulin in Patients With Polycystic Ovary Syndrome. Journal of Obstetrics and Gynaecology Research. 2026. https://doi.org/10.1111/jog.70442
  10. Faghfoori Z, Javadivala Z, Malek Mahdavi A. Effects of Nigella sativa on VCAM-1 and ICAM-1: A systematic review of preclinical and clinical studies. Journal of Cardiovascular and Thoracic Research. 2025. https://doi.org/10.34172/jcvtr.025.33343
  11. Razmpoosh E, Safi S, Abdollahi N, et al. The effect of Nigella sativa on the measures of liver and kidney parameters: A systematic review and meta-analysis of randomized-controlled trials. Pharmacological Research. 2020. https://doi.org/10.1016/j.phrs.2020.104767
  12. Thomas JV, Mohan M, Prabhakaran P, et al. A phase I clinical trial to evaluate the safety of thymoquinone-rich black cumin oil (BlaQmax) on healthy subjects: Randomized, double-blinded, placebo-controlled prospective study. Toxicology Reports. 2022. https://doi.org/10.1016/j.toxrep.2022.04.020
  13. Abumadini MM, Ahmad S, AlYahya W, et al. Clinical Uses of Nigella Sativa in Pediatrics: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. The Journal of Pediatric Pharmacology and Therapeutics. 2025. https://doi.org/10.5863/jppt-24-00044
  14. Sener K, Cakir A, Yesiloglu O, et al. Rhabdomyolysis and acute kidney injury after consumption of black seed oil. Toxicon. 2024. https://doi.org/10.1016/j.toxicon.2024.107787
  15. Arab A, Ramezaninejad S, Salehifar E. Extensive Subcutaneous Hematoma in a Patient Receiving Nigella sativa Oil, Dual Antiplatelet Therapy, and Oxaliplatin-Based Chemotherapy: A Case Report. Hospital Pharmacy. 2026. https://doi.org/10.1177/00185787261482136

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