Phytosterols are bioactive compounds that are naturally present in plant cell membranes with chemical structure similar to the mammalian cell- derived cholesterol. They are highly present in lipid-rich plant foods such as nuts, seed, legumes and olive oil. Among various phytosterols, β-sitosterol (SIT) is the major compound, found plentiful in plants. It has been evidenced in many in-vitro and in-vivo studies that SIT possesses various biological actions such as anxiolytic & sedative effects, analgesic, immunomodulatory, antimicrobial, anticancer, anti – inflammatory, lipid lowering effect, hepatoprotective, protective effect against NAFLD and respiratory diseases, wound healing effect, antioxidant and anti-diabetic activities. In this review, in order to compile the sources, characterization, biosynthesis, pharmacokinetics, antioxidant and anti-diabetic activities of SIT, classical and online-literature were studied which includes the electronic search (Sci Finder, Pubmed, Google Scholar, Scopus, and Web of Science etc) and books on photochemistry. The experimental studies on SIT gives a clear evidence that the potential phytosterol can be used as supplements to fight against life threatening diseases. High potential of this compound, classifies it as the notable drug of the future. Therefore, immense researches regarding its action at molecular level on life threatening diseases in humans are highly endorsed.