Maybe you’ve seen collagen advertised in food, skin cream, pills, or powders. The word is spreading about this nutrient important for a healthy, vibrant body.

But that isn’t anything new. You’ve been making it your whole life. Collagen is a type of protein that makes up most of the protein in your body, found in your muscles, bones, tendons, ligaments, organs, blood vessels, skin, intestinal lining, and other connective tissues.

So, why the need to promote collagen on store shelves? Is it something you should be buying? First, consider if your body is already making enough on its own.

When Your Collagen Levels Decrease

There is no blood test or another way to measure the amount of collagen in your body, but you can tell when your body doesn’t have enough.

As you age, your body naturally makes less. The slow-down can start in your mid-to-late 20s. That causes a variety of conditions that we usually accept as part of getting older:

• Skin loses elasticity. You form wrinkles and your wounds heal more slowly.
• Tendons and ligaments are stiffer. You lose flexibility.
• Muscle mass decreases. You become weaker.
• Cartilage wears down. You develop joint pain or osteoarthritis.
• Intestinal lining gets thinner. You may have more digestion problems.

To make collagen—or any protein—your body combines amino acids. You can get amino acids by eating and digesting protein-rich foods, like meat, beans, and dairy products. Then your body can repurpose the amino acids into collagen.

The Best Foods for Building Collagen

The best way to replenish the nutrients your body needs to make it is through your diet. Eating animal products, like beef, chicken, fish, and eggs will provide amino acids. So will beans and legumes, but one of the best foods for building collagen is bone broth. You can buy it in grocery stores or make it yourself.

Gelatin is another great food to boost your body’s ability to make collagen. Gelatin comes from collagen, so it naturally has what your body needs to turn it back into collagen form.

When to Take Collagen Supplements

Getting nutrients from eating fresh, organic foods is best. It’s what your body is made to consume and digest naturally. But collagen supplements are second best and still a good source if you’re traveling, eating on the run, or otherwise concerned that your diet isn’t as nutritious as it could be.

If you want to take a collagen supplement, opt for the powder form. Hydrolyzed (or “collagen peptide”) powder usually has no flavor and dissolves easily in beverages, smoothies, soups, and sauces.

Nourishing Your Skin

Some skin creams claim to contain synthetic collagen to help revitalize your skin. They may work by adding a film-like layer to your skin to reduce water loss and protect your skin from environmental elements. But don’t forget that your skin is your body’s largest organ. And a proven way to keep your organs healthy is with good nutrition.

Your skin is an outer reflection of your inner health, so it makes sense that the same way you nourish collagen stores throughout your body will nourish your skin too.

Note, however, that the number one cause of skin damage isn’t lack of collagen. It’s sun exposure. Replenishing it may not be able to undo years of sun damage.

It’s Easy as One Cup a Day

If your body has ample stores, then you are increasing your likelihood of having firmer skin, smoother-moving joints, and other signs of a healthy, youthful body.

The surest way to help your body produce collagen is by feeding it enough protein and other nutrients. It can be as easy as drinking one cup a day of bone broth or another beverage mixed with hydrolyzed collagen powder.