Campesterol is a phytosterol whose chemical structure is similar to that of cholesterol. Many vegetables, fruits, nuts and seeds contain campesterol, but in low concentrations. Banana, pomegranate, pepper, coffee, grapefruit, cucumber, onion, oat, potato, and lemon grass (citronella) are few examples of common sources containing campesterol at ~1–7 mg/100 g of the edible portion.

Being a steroid, Campesterol is a precursor of anabolic steroid boldenone. Boldenone undecylenate is commonly used in veterinary medicine to induce growth in cattle but it is also one of the most commonly abused anabolic steroids in sports. This led to suspicion that some athletes testing positive on boldenone undecylenate did not actually abuse the hormone itself but consumed food rich in Campesterol or similar phytosteroids.

Although studies in humans have shown that consumption of phytosterols may reduce LDL levels, there is insufficient evidence to recommend them as a treatment for hypercholesterolemia. Larger trials are needed to provide such evidence, and are underway. Animal studies have shown that campesterol and other phytosterols can reduce the size of atherogenic plaques, but there is no data yet to shown that consumption of phytosterols result in any clinical benefit such as a reduction in atherosclerosis, heart disease, cardiac events, or mortality.