What You Need to Know About Collagen Supplements

Collagen supplements come in many forms — including powders, pills, lotions, potions, smoothies and broths — and are purportedly good for everything from skin to joints. But how do they work? Here are some answers, from the daily dosage to whether they have any side effects.

Read more: Are Collagen Supplements Safe?

Collagen is big business, with global sales expected to grow to $6.5 billion by 2025, according to Grand View Research. It is made of amino acids, which are the building blocks of protein, says Cleveland Clinic. It is the most abundant protein found in your connective tissues and skin.

There are actually 16 types of collagen, but the majority in the body are type I, II or III. Types I and III are plentiful in skin, tendons, organs and bones, while Type II is found in the cartilage lining joints, according to the Arthritis Foundation.

In skin, collagen is responsible for the supple, elastic properties associated with youth, but your natural supply of collagen dwindles with advancing age, explains Dendy Engelman, MD, a dermatologic surgeon in New York City. "This means that our protein support is less and we lose the ability to retain moisture," she says. "To combat anti-aging, increasing collagen production is vital."

There are essentially three types of collagen supplements available today: gelatin, hydrolyzed and undenatured, according to the Arthritis Foundation. Gelatin and hydrolyzed collagen are broken down into smaller bits and pieces. Undenatured collagen, by contrast, is not broken into smaller parts nor used to build collagen. Instead, this form of collagen helps teach your immune system not to attack its own collagen stores in the hopes of reducing joint pain.

"For oral supplements, hydrolyzed collagen is easiest to digest as it is broken down into the smallest forms of peptides and amino acids," says Dr. Engelman. There are many sources of collagen. "The most impressive research studies collagen sourced from fish scales, and bovine collagen also has been proven effective," she says.

In a review of 11 studies published in January 2019 in the Journal of Drugs in Dermatology, researchers found that collagen supplements improve wound healing and skin aging. What's more, collagen increased skin elasticity, hydration and collagen density, with no reported side effects. The studies were small, however, and additional research is needed to identify the proper doses of collagen supplements, the researchers concluded.

When ConsumerLab.com, a nationally recognized independent testing company that verifies ingredients in supplements, ran a test of popular collagen supplements, it found that collagen can "modestly reduce" wrinkling and cellulite and may benefit joint pain and improve flexibility after two to six months of daily use.

Collagen supplements can be taken any time of day, Dr. Engelman says. Follow the dosing instructions on the label of the product you choose. But she also suggests asking your doctor about the best collagen supplements for you, depending on whether you want to focus on skin quality and texture or the health of your joints.

Mild side effects such as gastrointestinal symptoms, headache, dizziness and rash are possibilities. In addition, if you have allergies to specific sources of collagen, such as fish, it's wise to avoid collagen products derived from these sources.

It's also important to choose supplements labeled as "plant-based collagen builder" if you are a vegan or vegetarian, the Arthritis Foundation notes. These plant-based products do not actually contain collagen but reportedly support collagen production, although the science has not fully supported these claims.

If you're looking for collagen to plump and firm your skin, avoid collagen-based creams and other topical agents. "Collagen is a large molecule, which makes it hard to be absorbed by the skin when applied topically," Dr. Engelman explains. Different topicals may help.

"The best way to boost collagen is applying actives that increase your body's own production," she says. "The gold standard is retinol." There are also devices that use heat, ultrasound and radiofrequency to boost collagen production under the skin, she adds.

Read more: Collagen-Rich Foods to Help You Look and Feel Younger