The latest in trendy beauty nutrients combines the best of nature and science for noticeable results. Collagen, keratin, and ceramides—either in the form of youth-enhancing supplements or as key ingredients in topical serums, lotions, and creams—deliver smoother skin, thicker hair, and stronger nails. And they really work. Here’s what you need to know:

Collagen—You Start Losing It After 30

Collagen, the face-plumping protein, makes up about 80 percent of your skin, and its fibers give your skin firmness and strength. Collagen naturally starts to diminish after age 30, which causes skin to decrease in thickness by about seven percent every 10 years. Fortunately, supplements of type 1, 2, and 3 collagen can help prevent the signs of aging. Since collagen also strengthens hair and nails, and is essential for healthy bones and joints, supplementation is vital, especially if you don’t eat a diet rich in animal protein.

Many dermatologists question the effectiveness of collagen applied topically in cosmetics because skin cannot easily absorb its large molecules. However, the cumulative effect of topical collagen, when combined with collagen boosters such as vitamin C, peptides, and stem cells, shows positive results.

Keratin Grows Thicker & Longer Hair

Keratin is the protein that makes up 97 percent of your hair. It helps hair grow healthier, thicker, and longer. It also fortifies brittle nails, preventing them from splitting and breaking. Keratin has been an ingredient in topical hair products for years, and has recently become available in supplements as Cynatine HNS, which can help improve the health and appearance of skin, as well as hair and nails.

Ceramides—a Must for Winter

Ceramides occur naturally in the skin’s own oil and reinforce its protective barrier. They represent some 40 percent of the intercellular “cement” that binds cells together. Levels of ceramides in your skin decline with age, and are lower during the winter months, contributing to dry and inflamed skin.

Studies show that supplemental ceramides can lower inflammation and protect against moisture loss. While ceramides are traditionally derived from animal sources, “phytoceramides” from plants such as wheat grain or rice bran are one of the most effective recent advances in the maintenance of youthful skin. You can find them in both dietary supplements and hair care products.