Collagen is our body’s most abundant protein. But the science surrounding it is still in process—especially when it comes to supplements. Preliminary research suggests that collagen supplements may improve joint and bone health; skin, hair and nail quality; and more. Here are a few of the most current findings regarding this popular nutrient.

SUPPLE SKIN

A recent study by Korean and Japanese researchers, published in Nutrients, found that a collagen supplement may lead to better skin health. For 12 weeks, 64 women were given either a daily oral collagen peptide supplement or a placebo; those who took collagen experienced improvement in markers of skin hydration, elasticity and wrinkling compared with the placebo group. None of the participants reported any adverse effects.

SWEET SLEEP

The research on this is too new to be definitive, but some evidence suggests that collagen could promote better sleep if taken about one hour before bedtime. Numerous studies show that taking 3 grams of glycine—an amino acid that tends to be abundant in collagen—before you head to bed can lead to deeper, more restful sleep. Be sure to check your supplement to see if it has enough glycine to be effective.

STABLE SOURCE

A 2018 study at the Australian Institute of Sport concluded that collagen supplements provide higher and more reliable levels of amino acids than bone broth—a popular collagen source—whether prepared commercially or at home. Home bone-broth concoctions tended to have higher amino-acid levels than store-bought versions, but both fell short of levels found in various collagen supplements.

SUGAR STABILIZER

Oral collagen supplements may help normalize fasting blood-glucose levels in people with type 2 diabetes and reduce the levels of pharmaceutical drugs they need, according to a 2018 study published in the Journal of Clinical Nutrition and Food Science. The double-blind, randomized research examined 60 participants over 12 weeks who took fish collagen peptides and found that they improved blood-sugar markers as well as or better than those taking diabetes medication.

GOOD BUY

When stocking up on collagen, the source matters. One of our top picks:

NeoCell, which has been in the collagen business since 1998. Try its Super Collagen Powder or, if you prefer tablets, opt for Super Collagen+C. The added vitamin C contributes to healthy, beautiful skin.