Black Cumin (Thymoquinone): 10 Benefits & How to Use
Written by 
Dr. Michael Ruscio, DC on
May 19, 2025
Written by
Dr. Michael Ruscio, DC on May 19, 2025
—
Reviewed by 
Hilary Watts
Although most of us have a few go-to natural products for minor ailments, I’m betting that black cumin seed oil isn’t among them. Despite a 3,000-year legacy, this ancient essential oil is not well known—yet its key compound, thymoquinone (TQ), is gaining attention for a wide range of health benefits and low toxicity.
Curious about the full potential of black cumin, I asked our clinical team to research this medicinal plant and its active constituent. Overall, I was impressed by what we found.
In this article, I’ll walk you through the therapeutic potential of black cumin seed oil and what TQ might offer.
What Is Black Cumin Seed Oil?
Black cumin seed oil, also known as black seed oil, comes from the seeds of Nigella sativa, a plant native to the Middle East, South Asia, and North Africa.
Nigella sativa oil use stretches back over three millennia—Nigella sativa seeds were found in King Tut’s tomb. Cleopatra is said to have used the oil for skin care, and Hippocrates recommended it for digestion 1 2 3.
The oil contains over 100 active compounds, but thymoquinone is the standout active ingredient 1 2 3.
Studies suggest TQ has effects that are 1:
- Antioxidant
- Antimicrobial
- Anti-inflammatory
- Immunomodulatory
- Anti-cancer—for example, a lab study found that TQ induced apoptosis (programmed cell death) of cancer cells in the liver, suggesting it may be hepatoprotective (specifically helpful for the liver) 4
A 2021 review stated that the “health benefits of black cumin and its bioactive TQ cover almost every physiological system” 1. That’s big talk, so let’s examine the viability of these health promises in more detail.
10 Potential Benefits of Thymoquinone
Research points to these 10 potential positive effects of Nigella sativa (black cumin seed) oil and its active ingredient, thymoquinone:
- Reducing Joint Pain
Black seed oil may help joint pain by decreasing the inflammatory markers CRP and TNF-alpha 5. It also causes inhibition of COX-2 enzymes, having a similar effect as non-steroidal anti-inflammatories like ibuprofen 6.
In a randomized controlled trial (gold-standard study), 116 patients with knee osteoarthritis took either a placebo or black seed oil for a month 7. The black cumin seed oil group had much better results, including:
- A 34% decrease in pain (vs 9% in the placebo group)
- A 28% increase in physical function (vs 1% in the placebo group)
- Reduced painkiller use
In another randomized controlled trial, 40 women with rheumatoid arthritis took either standard therapy plus a placebo or standard therapy plus black seed oil for one month. In this study, the black seed oil group had 8:
- Decreased disease activity
- Improved joint swelling & stiffness
Key Takeaway: These results suggest that black cumin seed oil may offer a protective effect for inflammatory joint conditions. However, with only a couple month-long studies, follow-up research is needed to confirm any lasting effects.
- Combating Infections
There are various ways that black seed oil may be able to fight microbial infections:
- It increases levels of T helper cells (a type of immune cell), which help mobilize other immune cells to fight infections 9.
- It disrupts bacterial cell membranes and prevents harmful microorganisms from building protective biofilms around themselves 10.
- It can induce oxidation processes (lipid peroxidation) within parasites, damaging their DNA 11.
- It may bind to and damage fungal membranes 11.
For parasitic and fungal infections, animal models and studies of cell lines show that black seed oil can act as an inhibitor of organisms like Babesia and Candida 10 12.
For bacterial and viral infections, we also have some in vivo studies in humans:
- A 2024 meta-analysis (a study of studies) of over 1,000 hospitalized COVID-19 patients found that black cumin seed oil cut their risk of death by 78% 13.
- Three small randomized controlled trials suggest the oil can also help eliminate H. pylori infections. In one of these clinical trials, 51 H. pylori patients received standard antibiotic therapy plus either black seed oil or a placebo for 8 weeks. At the end of the trial, 88% of the black seed oil group were cleared of H. pylori, versus only 55% of the placebo group 14.
Key Takeaway: The antimicrobial scope of black cumin seed oil is impressive. Specifically for H. pylori, we’ve had good results using probiotics, so black cumin could be a useful add-on. However, there are still gaps in data for parasitic and fungal infections, as in vitro (test-tube) and animal studies don’t always translate to clinical benefits for humans.
- Supporting Thyroid Function
Black seed oil might be a help to folks with autoimmunity by supporting thyroid function, calming inflammation, cutting anti-TPO antibodies, and lowering VEGF—a protein tied to thyroid inflammation and cancer 15.
In one randomized controlled trial, 40 Hashimoto’s patients took either a placebo or black seed oil for two months 15. The black seed oil group saw their:
- TSH improve (reduce) by 2.29 mIU/L
- T3 improve (increase) by 0.14 nmol/L
- Anti-TPO antibodies drop by 147 IU/mL
- Weight decrease by 2.5 lbs
- VEGF levels fall—This matters because high VEGF fuels abnormal blood vessel growth and inflammation in thyroiditis—less VEGF could mean less trouble.
Key Takeaway: Current results hint that black seed oil could help manage Hashimoto’s by tweaking thyroid markers and calming inflammatory signaling pathways and mediators, such as inflammatory cytokines. That said, it’s just one small study—more evidence is needed before drawing solid conclusions.
- Reducing Asthma and Allergies
Black seed oil might ease asthma and allergies by acting like an antihistamine 16, while also dialing down the immune response that drives allergic reactions 17.
A 2020 meta-analysis of randomized controlled trials with a total of 187 asthma patients found that black cumin seed oil at various dosages improved 18:
- Asthma control scores
- Lung function, measured as forced expiratory volume
Another trial gave 65 patients with seasonal allergies either a placebo or black seed oil capsules plus black pepper extract twice daily after meals for 15 days. The black seed oil/black pepper group showed 17:
- Lower serum IgE (an antibody key to allergic reactions) and eosinophils (white blood cells linked to allergies)
- Better nasal and eye symptoms
- Far fewer severe symptoms by the end—Only 3% of the black seed oil/pepper group versus 66% of the placebo group had severe symptoms.
Given the combo of treatments, we can’t parse out which was the most effective: the black seed oil, the black pepper extract, or both.
Key Takeaway: Black seed oil looks promising for calming asthma and allergy symptoms. Still, larger and longer studies are needed to confirm these benefits and to see if they hold up over time.
- Boosting Cognition
Black cumin seed oil could support brain function by reducing neuroinflammation 19 and slowing the breakdown of acetylcholine, a key player in learning and memory 20. Some Alzheimer’s medicines, like Donepezil, Rivastigmine, and Galantamine, work the same way.
In a randomized controlled trial, 40 healthy older adults took either a placebo or black seed oil capsules for 9 weeks. The black seed oil group showed gains in 21:
- Memory
- Attention
- Processing speed
- Cognitive flexibility
That said, we don’t have studies on black seed oil in Alzheimer’s patients, so this is just healthy adults for now.
Key Takeaway: Black seed oil looks promising for sharpening cognition, especially in older folks. More research would help fill in the blanks as to whether it also helps those who already have dementia symptoms.
- Dissolving Kidney Stones
Black cumin seed oil might help with kidney stones by stopping dietary calcium oxalate from forming crystals in the kidneys and preventing the oxidative stress kidney stones cause 22.
In a randomized controlled trial, 60 patients with kidney stones larger than 5 mm took either a placebo or black seed oil mixed in honey daily for 10 weeks 22. Among the black seed oil group:
- 44% completely passed their stones
- 52% had a significant reduction in stone size
Key Takeaway: Research suggests black seed oil could aid in breaking down kidney stones and help flush them out while keeping kidneys healthier. However, it’s just one promising study—no similar research backs it up or challenges it yet.
- Balancing Female Hormones
Black seed oil might help regulate women’s hormones as it contains plant-based compounds that can mimic or interact with estrogen and estrogen receptors in the body.
A few studies back this up.
- In one trial, menopausal women applied black seed oil below the navel twice daily and experienced less urinary incontinence 23.
- Another trial that gave postmenopausal women black seed oil plus Vitex reduced hot flashes 24. However, it’s hard to separate the effects—it’s unclear whether the benefit came from Vitex, black cumin seed, or the combination.
- A different trial found that PCOS (polycystic ovary syndrome) patients taking 1,000 mg/day of black seed oil had more regular periods, plus lower testosterone and reduced facial hair growth 25.
Key Takeaway: Black seed oil shows potential for smoothing out female hormones thanks to its phytoestrogen-like action, but we’d need more research to say it’s a sure bet for everyone. Other herbals like Vitex, dong quai, and black cohosh contain higher levels of estrogen-mimicking phytochemicals, and black cumin wouldn’t necessarily be my first pick for balancing hormones.
- Improving Acne
Black seed oil could help acne, thanks to its cytotoxic (cell damaging) actions against the skin bacteria Propionibacterium acnes and Staphylococcus aureus, at least in lab tests 26.
One randomized controlled trial put this to the test in 60 acne vulgaris patients, treating their skin with either a topical placebo gel or a black seed oil gel twice daily for two months 27. The black seed oil group saw:
- A 70–80% reduction in acne lesions
- A 78% drop in acne severity
- A 63% enhancement in quality of life
Key Takeaway: From one study, black cumin seed oil looks like a solid option for tackling acne. But we’d need to see these results repeated a few times to know if it’s consistently effective for clearing pimples.
- Lowering Cholesterol & Blood Sugar
Black seed oil, with about 60% linoleic acid—an omega-6 fat, might help lower cholesterol and cut heart disease risk while boosting insulin sensitivity.
A 2024 meta-analysis of 34 studies, covering 2,300 people, found that black seed oil, especially at doses over 2,000 mg/day, improved these metabolic markers 28:
- Total, LDL, and HDL cholesterol
- Triglycerides
People with higher cholesterol saw the biggest wins.
Meanwhile, a 2019 meta-analysis showed that black seed oil dropped fasting blood sugar by 10 points and improved HbA1c (a longer-term measure of how well the body controls glucose) by 0.6% 29.
Key Takeaway: Black seed oil, particularly at higher doses, looks like a strong player for improving cholesterol, triglycerides, and blood sugar control if your numbers are off.
- Improving Sleep
Black seed oil might help you sleep better by lowering cortisol (a stress hormone) and orexin A (a brain chemical that keeps you awake) 30.
A recent study tested this in 70 adults struggling with poor sleep. They took either placebo or black seed oil softgels just before getting into bed for one week 31. Here’s what happened in the black seed oil group (but not those who took the placebo):
- A 75% jump in sleep quality scores (from a questionnaire)
- A 19% increase in total sleep time
- A 35% faster time falling asleep
However, the study was funded by the company making the supplement, so there’s a chance some bias may have crept in.
Key Takeaway: One study suggests black seed oil has real promise for boosting sleep quality. But some independent testing would be good to ensure it’s not too good to be true. And supplements should never replace more fundamental steps to improve sleep quality.
Black Seed Oil: A Practical User Guide
In the studies we looked at, black cumin seed oil had health benefits in oral doses from as little as 200 mg to as high as 6 g (6,000mg)/day.
At the clinic, we generally start clients at 1g (1,000 mg) of black cumin seed oil a day taken by mouth, working up from there if there are no problems with tolerating it. If you’re using lower dosages, it’s a good idea to look for a product that has a higher level of thymoquinone (5% or over).
Here’s a graphic of how we use black cumin seed oil in the clinic:
In our experience, you can expect to see the effects of thymoquinone-rich black cumin oil after a few weeks. If you don’t get the benefit you’d hoped for, check in with a practitioner to see if there are other things you can do to move the needle on your symptoms.
Given the gaps in data, also work with a doctor if you are pregnant or considering long-term use of thymoquinone.
Thymoquinone: Our Standpoint
Black cumin seed oil—and its key ingredient thymoquinone—has a long history and a growing body of promising research. For example, it appears to have anti-inflammatory effects and can safely deliver benefits for joint pain, infections, and thyroid support. Still, much remains to be understood about its complete mechanisms of action and the molecular mechanisms driving these effects.
Given these uncertainties, it’s wise to start low, monitor your response, and work with a qualified healthcare provider.
At the Ruscio Institute for Functional Health, we help people with a range of symptoms related to digestive health, thyroid health, immunity issues, and beyond. If you are struggling with any of these issues, you don’t need to do so alone—please reach out.
The Ruscio Institute has developed a range of high-quality formulations to help our clients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you. The information on DrRuscio.com is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.
Dr. Michael Ruscio is a DC, natural health provider, researcher, and clinician. He serves as an Adjunct Professor at the University of Bridgeport and has published numerous papers in scientific journals as well as the book Healthy Gut, Healthy You. He also founded the Ruscio Institute of Functional Health, where he helps patients with a wide range of GI conditions and serves as the Head of Research.➕ References
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