The chemical makeup of Nigella sativa is mainly shaped by its rich volatile and fixed oils, which contain many active compounds. The most important of these is thymoquinone, a powerful substance found in high levels in the essential oil and well known for its antioxidant and anti-inflammatory benefits. Other key volatile components include p-cymene, carvacrol, thymol, nigellone (dithymoquinone), and alpha-pinene. The seeds also contain a high level of fixed oil, which is rich in essential fatty acids such as linoleic acid (omega-6) and oleic acid. In addition, Nigella sativa provides unique alkaloids like nigellidine, nigellicine, and nigellimine. The presence of saponins, especially alpha-hederin, along with various phenolic compounds, further adds to the plant’s wide range of biological activities.