Exosomes are tiny vesicles that act as messengers, delivering molecules between cells. Because plant exosomes are biomimetic—i.e., composed of a phospholipid bilayer similar to the skin’s—they can effectively deliver active ingredients deeper into the skin, at optimal potency. The exosomes in goop Beauty’s Exosome Hydration Therapy Serum—there are over 3 million of them per bottle—are derived from cica leaf, a plant that’s traditionally been used to soothe and hydrate skin. These exosomes also increase skin penetration for faster, more effective results. The serum contains a high-performance complex of carefully chosen ingredients: Hyaluronic acid and polyglutamic acid work synergistically to attract and retain moisture. Antioxidant snow mushroom and red sea moss work together to form a protective barrier on skin to defend against the external aggressors that can prematurely age skin’s appearance, while also moisturizing and reducing transepidermal water loss. And acetyl glucosamine helps stimulate hyaluronic acid production in the skin. Formulated without fragrance, the clear gel has a rich, viscous texture that feels silky, cooling, and protective on skin. And the clinical results are compelling: After just one week of use, 100% of the subjects showed significant improvement not just in hydration and barrier function—but also in skin’s plumpness, radiance, elasticity, smoothness, and texture.* *Clinical measurements taken after single application on 30 women ages 30 to 55 .