Phytosterols are plant-derived compounds structurally similar to cholesterol and are commonly found in nuts, seeds, and vegetable oils. While their primary scientific validation is for cholesterol-lowering effects, there is also evidence suggesting weak estrogenic activity, as some phytosterols can bind to estrogen receptors and mildly modulate estrogenic pathways. Studies have shown that phytosterols, such as beta-sitosterol, can act as selective estrogen receptor modulators (SERMs) with very weak estrogen-like effects, potentially influencing hormonal balance in postmenopausal women or those with estrogen deficiency. However, compared to phytoestrogens (such as isoflavones from soy), phytosterols have significantly less potent estrogenic effects.

Clinical data on phytosterols specifically for supporting the "Estrogen body system" (i.e., for hormone balance, menopause symptoms, or related women's health issues) are limited and not robust. Most of the evidence comes from in vitro (cell-based) or animal studies. Human trials are rare, and those that exist usually focus on lipid metabolism rather than estrogenic endpoints. As such, while there is a plausible mechanism and some preclinical data, the evidence supporting phytosterols for estrogenic support is moderate at best. They are not considered primary agents for estrogen support but may have ancillary benefits.