Black seed oil has shown promise in treating some of the most common health conditions, including high blood pressure and asthma. It also shows strong antifungal activity against Candida albicans, yeast that can overgrow in the body and lead to candidiasis. Examples of other black seed oil health benefits include:

• Reducing high blood pressure: Taking black cumin seed extract for two months has been shown to reduce high blood pressure in people whose blood pressure is mildly elevated.
• Reducing high cholesterol: Taking black seed oil has been shown to reduce high cholesterol. It's high in healthy fatty acids that can help you maintain healthier cholesterol levels. Examples of these fatty acids include linoleic acids and oleic acid. The levels of the oils can vary depending on where the black seeds are grown. People may also see results when consuming the crushed seeds.
• Improving rheumatoid arthritis symptoms: Taking oral black seed oil may help to reduce inflammatory rheumatoid arthritis symptoms.
• Decreasing asthma symptoms: The anti-inflammatory effects of black seed oil may extend to improving asthma symptoms. Its effect in reducing inflammation in the airways may also help with bronchitis symptoms.
• Reducing stomach upset: Eating black seeds or taking black seed oil is associated with relieving stomach pain and cramps. The oil can help to reduce gas, stomach bloating, and the incidence of ulcers as well.

Black seed oil is also thought to have anticancer properties. It may help fight against skin cancers when applied topically.

Portions of black seed oil known as thymoquinone and other seed potions were able to reduce the growth of tumors in lab rats. The oil also may help to reduce the tissue damaging effects of radiation that is used to kill cancer cells. But these results haven't been studied in humans. Black seed oil shouldn't be used as a substitute for conventional cancer treatments.