Although studies in humans have shown that consumption of phytosterols may reduce LDL levels, evidence to recommend them as a treatment for hypercholesterolemia is insufficient. 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 no data yet show that consumption of phytosterols results in any clinical benefit such as a reduction in atherosclerosis , heart disease , cardiac events, or mortality. 
Research has indicated that stigmasterol may be useful in prevention of certain cancers , including ovarian , prostate , breast , and colon cancers . Studies have also indicated that a diet high in phytoesterols may inhibit the absorption of cholesterol and lower serum cholesterol levels by competing for intestinal absorption. Studies with laboratory animals fed stigmasterol found that both cholesterol and sitosterol absorption decreased 23% and 30%, respectively, over a 6-week period. It also possesses potent antioxidant , hypoglycemic and thyroid inhibiting properties. 
Progestins are steroid hormones that are typically prescribed to postpone heat cycles or alleviate false pregnancies in female dogs and treat benign prostatic hypertrophy in male dogs. They may also be used for some types of skin problems or to modify aggressive behavior. Megestrol acetate and medroxyprogesterone are the most commonly used progestins in dogs. Potential side effects include increased thirst and appetite, behavioral changes, mammary gland enlargement, and an increased likelihood of developing diabetes mellitus, acromegaly (a hormonal disease that causes enlargement of the head), Cushing’s disease, uterine infection (pyometra), reproductive disorders, and some types of cancer.