###### Abstract  
It has been previously demonstrated in light microscopic and immunohistochemical studies that ovariectomized rats receiving young coconut juice at 100 mL/kg BW showed much better wound healing and improved skin complexion. Nevertheless, it was found that young coconut juice at 100 mL/kg BW/day caused unfavorable side effects, such as glycogen deposition in the liver. Therefore, in the current study, 3 lower doses (10, 20, and 40 mL/kg BW/day) were optimized, and the ultrastructure was further investigated. Compared to normal rats, all the parameters regarding skin changes, including epidermal and dermal thickness, the number of hair follicles, the diameters of collagen fibrils, perimeters, and nuclei of fibroblast and keratinocyte cells, and ultrastructural changes in keratinocyte and fibroblast cells were significantly reduced in ovariectomized rats. Those parameters in the ovariectomized rats were restored to normal by injecting estradiol benzoate or by feeding young coconut juice to the rats, where the effect was found to be dose-related but not in the case of all the parameters. In most cases, a dose of young coconut juice of 40 mL/kg BW/day was the optimal dose. The results suggest that young coconut juice may be as effective as estradiol benzoate in reducing skin atrophy/aging, probably as a selective estrogen receptor moderator.  
y 2022 2  
Estrogen replacement therapy can improve keratinocyte proliferation, epidermal thickness, skin supplements, collagen content and quality, and vascularization, and reduce wrinkles, all of which effects can help to reverse these skin changes [8; 11; 12]. Hormone replacement therapy (HRT) can help protect the skin as one becomes older, especially if one is going through menopause (the period when estrogen levels drop dramatically). Despite this, HRT increases the risk of a variety of cancers, including invasive breast cancer [13] and uterine cancer [14; 15], as well as cardiovascular illness, including an increased risk of heart attack, stroke, and blood clots [13]. Phytoestrogens are naturally occurring selective estrogen receptor modulators (SERMs) that can provide a natural estrogen replacement for postmenopausal women.  
This research team discovered in 2006 that ovariectomized (ovx) rats given young coconut juice (YCJ) demonstrated considerably improved wound healing (including reduced scarring), brighter skin, and shorter hair than controls [16]. The phytoestrogenic properties of YCJ [17], binding with ER\(\alpha\) and ER\(\beta\)[18] and downregulated the macrophage migratory inhibitory factor (MIF) [19], were later discovered to be responsible for the favorable effects of YCJ on accelerating cutaneous wound healing. At 100 mL/kg BW/day, the YCJ supplement had adverse side effects, such as glycogen accumulation in the liver [18]. As a result, three lower dosages of YCJ (10, 20, and 40 mL/kg body weight, respectively) were used in the current investigation. Using ovariectomized rats as a model for postmenopausal women, the current study aimed to determine the optimal dose of YCJ, with the fewest adverse effects on cutaneous alterations, to alleviate skin problems in aging/menopausal women using light microscopy (LM) and transmission electron microscopy (TEM).