Пхитостеролису природни биљни молекули слични холестеролу. Фитостероли се налазе у разним биљкама, али су посебно богати у орашастим плодовима, пасуљу, сунцокрету, сојином зрну и биљним уљима, укључујући конопљу, кикирики и репицу. Фитостероли се промовишу због многих својстава која ублажавају упале, а чак су и повезани са стимулацијом раста косе и смањењем холестерола. Долазе у облику оралних додатака и такође се користе за прављење хидратантних крема и лосиона.
Several studies have examined the effects of phytosterols on the skin. A study in Germany had 10 subjects apply different types of moisturizers to their skin, including vitamins, ceramides and phytosterols. Researchers have found that using a moisturizer containing phytosterols and ceramides can prevent the breakdown of collagen in the skin, which occurs when the skin is exposed to sunlight. As you can imagine, years of exposure to the sun's UV rays can cause the skin to lose collagen; therefore, having a moisturizer that reduces this breakdown process can help slow aging. They also found that moisturizers containing phytosterols even had some stimulating effect on collagen production.
Another study found that phytosterols increased collagen and hyaluronic acid production in human fibroblasts; these cells are part of the skin's connective tissue and help repair damaged skin. This is important, why? Hyaluronic acid is a primary humectant, and moisturizing means helping the skin retain moisture.