Nigella sativa: might not be a testosterone booster, but is an effective slimming supplement

The seeds of Nigella sativa – perhaps better known as black cumin – contain substances that have been shown to boost the secretion of testosterone in animal studies. Whether they have the same effect in humans is not yet known. When Indonesian researchers gave Nigella sativa to overweight human subjects they observed no effect on testosterone levels, but the supplement did cause significant weight loss.

Nigella sativa
Nigella sativa is an Asian plant. The dried seeds are a spice that you might know under the name of black cumin. These contain compounds that researchers are finding increasingly interesting.

Thymoquinone [first structural formula on the right] for example, a compound that interacts with opioid receptors and may help reduce allergic reactions [WO 2010133574 A1]] and also has an anti-epileptic effect. [Epilepsy Res. 2011 Jan;93(1):39-43.]

Or anethole [second structural formula], a compound with a sedative and analgesic effect. [WHO Food Additives Series 14 (466)]

Nigella sativa also contains nigellone, melanthin, nigilline and damascenine.

Nigella sativa & testosterone
Athletes are showing increasing interest in supplements that contain extracts of Nigella sativa or oil from the seeds: Black Seed Oil. One of the reasons for this is that animal studies have shown that Nigella sativa boosts testosterone levels. [J. Pharm. Sci. & Res. Vol. 7(4), 2015, 234-237.] [International Journal of Pharmacology, 3: 27-33.] [Egyptian Journal of Sheep and Goat Sciences, Vol. 8 (1), P: 47-56, 2013.] The figure below comes from a comparable study. [Iran J Reprod Med. 2012 Jul;10(4):355-62.]


The animals in the experimental group were given an alcohol extract of Nigella sativa seed every day. The human equivalent of the dose they used would be 4-10 mg per day. That’s on the high side, and may not be a safe dose.

Nigella sativa & weight loss
Indonesian researchers at Sam Ratulangi University School of Medicine published a human study in 2010 in which they gave 39 overweight subjects aged between 35 and 45 a supplement containing Nigella sativa. [Acta Med Indones. 2010 Jul;42(3):130-4.] The Indonesians didn’t use an extract, but gave their subjects ground dried Nigella sativa seeds.

They gave half of their subjects 1500 mg Nigella sativa twice a day for three months. The powder was in capsules, each of which contained 750 mg extract. The other half of the subjects were given a placebo.

Nigella sativa had no effect on the men’s testosterone level. But the supplementation did cause the subjects to lose 4.5 kg weight and a reduction in waist circumference of 1.4 cm. Moreover, the supplement reduced systolic blood pressure.


“It is suggested that larger dose and longer duration of Nigella sativa consumption will give better results”, the researchers wrote.

Interesting stuff, this Nigella sativa. Watch this space.

Efficacy of Nigella sativa on serum free testosterone and metabolic disturbances in central obese male.


to study the efficacy of Nigella sativa in central obese men on serum free testosterone, body weight, waist circumference, blood sugar, lipid, uric acid, adiponectin, hs-CRP, and side effects in the treatment group compare to control.

an experimental, clinical test, double blinded with placebo control, pre-test and post-test design. Subjects are 30-45 years old, divided into the treatment and control groups, and evaluated weekly for 3 months. Data obtained were subjective complaints, body weight, waist circumference, and blood pressure, serum free testosterone, fasting blood sugar, triglyceride, HDL-Cholesterol, uric acid, creatinin, SGOT and SGPT, adiponectin, and hs-CRP. Data collected from March 2007 to June 2007 at Prof.Dr.RD Kandou General Hospital, Manado, North Sulawesi, Indonesia. Statistical analysis was performed using descriptive for subjects characteristic and drug’s side effect, t independent to compare between two parametric independent variables, Mann-Whitney U to compare between two non-parametric independent variables, and Wilcoxon Signed Ranks test to compare between two non-parametric dependent variables.

in the treatment group, complaints related to central obesity disappear in first week, very significant reduction of body weight, waist circumference, and systolic blood pressure, insignificant reduction in serum free testosterone, diastolic blood pressure, fasting blood sugar, triglyceride and cholesterol-HDL, uric acid, hs-CRP, and insignificant increase of adiponectin. On comparison between both groups, we found a very significant reduction on body weight and waist circumference, but the insignificant reduction on serum free testosterone, systolic and diastolic blood pressure, and the unsignificant increase of adiponectin, meanwhile the reduction of serum free testosterone in the treatment group was smaller than the control group, that means Nigella sativa could inhibit the decreasing of serum free testosterone. No side effects were detected in the treatment group.

although the other variables in the treatment group were not significantly different, we found them better than the control group, which can be a good sign for metabolic restoration in COM. It is suggested that larger dose and longer duration of NS consumption will give better results.

PMID: 20724766 [PubMed – indexed for MEDLINE]


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