Sunflower oil is pressed from the seeds of the sunflower. In foods, sunflower oil is used as a cooking oil. Sunflower oil is also used as medicine.

Sunflower oil is most commonly used for high cholesterol and preventing heart disease.

How does it work ?
Sunflower oil is used as a source of unsaturated fat in the diet to replace saturated fats

Possibly Effective for
Heart disease. There is some evidence that using sunflower oil that contains high amounts of oleic acid in place of dietary fats with higher amounts of saturated fat might reduce the risk of heart disease. The suggested amount of high-oleic acid sunflower oil is about 20 grams (1.5 tbsp) per day in place of other fats and oils. Sunflower oil that contains lower amounts of oleic acid does not seem to be beneficial.
High cholesterol. Most research shows that including sunflower oil in the diet lowers total cholesterol and "bad" low-density lipoprotein (LDL) cholesterol in people with high cholesterol. However, consuming sunflower oil may be less effective at reducing cholesterol compared to palm oil and flaxseed oil. Further, sunflower oil might not be effective for lowering cholesterol in people with peripheral vascular disease or those at risk for atherosclerosis.
Athlete's foot (Tinea pedis). Some research suggests that applying a specific brand of sunflower oil (Oleozon) to the foot for 6 weeks is as effective as the drug ketoconazole for curing athlete's foot.
Possibly Ineffective for
High blood pressure. Taking sunflower oil for up to one year appears to be less effective than olive oil at lowering blood pressure in people with high blood pressure.
Insufficient Evidence for
Hardening of the arteries (atherosclerosis). Some early research shows that sunflower oil might reduce the extent of atherosclerosis in the arteries and improve blood vessel health in people who are overweight or obese. But other early research suggests that sunflower oil is less effective than fish oil for reducing plaque in the arteries of people with atherosclerosis.
Dry skin. Early research suggests that applying sunflower oil to the dry skin of newborns might help with moisturization. But it might also hinder the development of normal skin barrier function that occurs during the first 4 weeks of life.
Growth and development in premature infants. Early research suggests that, when a mother massages her very small premature infant with sunflower oil, the baby puts on weight faster than when the baby is massaged without oil or not massaged at all. But massaging with sunflower oil doesn't seem to increase the length or head circumference of the infant.
Joint pain and swelling (inflammation) that is caused by an infection (reactive arthritis). Early research suggests that taking sunflower oil for 3 weeks does not improve symptoms in people with Reiter's syndrome.
Rheumatoid arthritis (RA). Early research suggests that taking sunflower oil for 3 weeks does not improve symptoms in people with rheumatoid arthritis.
Skin conditions, when applied to the skin.
Wound healing, when applied to the skin.
Other conditions.
More evidence is needed to rate the effectiveness of sunflower oil for these uses.