肝糖(英語：glycogen，又稱糖原、動物澱粉)是人類等動物和真菌儲存醣類的主要形式；是多醣的一種，由葡萄糖脫水縮合作用而成。主要生物學功能是作為動物和真菌的能量儲存物質。

在人體中，肝糖主要由肝臟和肌肉(主要為骨骼肌)的細胞產生與儲存，並且作為長期儲存的次級能量(還有作為儲存的主要能量是在脂肪組織積累的油脂)。肝糖可以由肝臟細胞和肌肉細胞合成。由肝糖轉化的葡萄糖會給全身各處使用，包括中樞神經系統。

在肝臟細胞(肝細胞)，肝糖可以在飯後不久構成。只有儲存在肝臟的肝糖可以由其他器官使用。在肌肉，肝糖的濃度較低(約肌肉質量的1-2％)。人體的肝糖主要儲存在肝臟、肌肉和紅血球。

來源：https://zh.wikipedia.org/zh-tw/%E7%B3%96%E5%8E%9F

【Glycogen】
Rating: Good
Benefits: Hydration
Categories: Humectant

Glycogen is a polysaccharide of glucose, a sugar that’s naturally present in the body, including the skin. Although its cell-energizing and signaling roles in the body has been known for decades, only recently has its role in skin been elucidated.

As it turns out, glycogen naturally occurring in skin and applied topically has been shown to help maintain and replenish ceramides, a type of sphingolipid in skin’s moisture barrier. Along with barrier maintenance, glycogen helps provide antioxidant defense from various types of airborne particulate pollutants shown to prematurely age skin.

Glycogen in skin care is often made enzymatically from breaking down natural foods such as corn, grains, or starchy vegetables. It may also be made from bacterial fermentation or animal-derived, the latter being a form Paula’s Choice Skincare doesn’t use. The usage level of glycogen in skin care is typically 0.05–0.3%, with the higher levels achieving greater anti-aging and hydrating benefits. Levels below 0.3% still offer efficacy when combined with similar ingredients. Glycogen is considered safe as used in cosmetics since it occurs naturally in the body and within skin.

https://www.paulaschoice.com/ingredient-dictionary/ingredient-glycogen.html?srsltid=AfmBOoq8b3IbSV-s0VapbrzX88XsfPFQeI0xqZdBDbsiRZ2cFvZGkEd3