Effect of Nigella sativa Oil on Early Menopausal Symptoms and Serum Levels of Oxidative Markers in Menopausal Women: A Randomized, Triple‑Blind Clinical Trial

Background: The declining levels of estrogen during menopause are linked with numerous somatic and psychological complications. Objectives: This study aimed to examine the effect of Nigella sativa (N. sativa) oil on early menopausal symptoms and serum levels of some oxidative markers in postmenopausal women. Methods: This randomized placebo trial was conducted on 72 menopausal women aged 45– 60 years. Participants were randomly allocated to placebo and intervention groups with an equal allocation ratio (1:1). Patients in the intervention group received one N. sativa oil capsule (1000 mg), whereas the placebo group received a placebo capsule at night for 8 weeks. Data were collected through the demographics questionnaire, the Greene’s Climacteric Scale, and a form for recording the number of daily hot flashes. Furthermore, the serum levels of total antioxidant capacity (TAC) and malondialdehyde (MDA) were measured before and 8 weeks after the intervention. Data were analyzed using the independent‑samples t, Chi‑square, Mann‑Whitney U, and Friedman tests as well as the repeated‑measures analysis of variance. Results: The participants were matched in baseline values. The mean baseline score of the Greene’s scale was 22.5 ± 9.5 in the intervention group and 20.0 ± 8.0 in the placebo group (P = 0.397). Mean scores had significantly reduced in both groups at the end of weeks 4 and 8. However, the intervention group experienced a more remarkable decrease in Greene’s score (adjusted MDLog10 = −0.16 (−0.29 to −0.05); P = 0.019). There were no significant differences between the two groups in the subscales of Greene’s scale (P 0.05). No significant difference was observed between the groups in serum levels of TAC (P = 0.250) and MDA (P = 0.444). Conclusion: N. sativa reduced the total score of menopausal symptoms and hot flashes in menopausal women; however, it had no significant effect on the serum levels of oxidative stress markers.