Collagen for Weight Loss: Does it Work?

Collagen is a major structural protein, making up 25 to 30 percent of the proteins in your body. It gives structure to connective tissue like:

• skin
• cartilage
• tendons
• ligaments
• muscles
• bone
• blood vessels

Natural collagen

Collagen is made of amino acids, which are considered the building blocks of protein. The amino acids glycline, proline, and hydroxyproline account for 57 percent of the total amino acids in collagen.

Amino acids are shaped like chains. In collagen, the amino acids are tightly twisted like a rope, making collagen extremely strong and stable.

In the body, collagen is naturally produced by cells called fibroblasts. Optimal collagen formation requires getting enough high-quality protein and vitamin C in your diet. You can also get collagen directly by eating certain foods and by consuming supplements.

Collagen supplements

Collagen supplements are made from the bones and tissues of animals, like cows, horses, pigs, or fish. The goal of these supplements is to help your body rebuild collagen. Types of collagen supplements include:

• Gelatin. Gelatin, or cooked collagen, is made by heating collagen for a long time. The heat degrades collagen, forming smaller proteins.
• Hydrolyzed. If the proteins are further broken down into amino acids, it’s known as hydrolyzed collagen. This form is also called hydrolyzed gelatin, collagen peptides, or collagen hydrolysate.
• Undenatured. Undenatured collagen is intact and hasn’t been degraded.

Collagen supplements are available in several forms:

• pills
• gummies
• powders
• liquid
• in packaged foods or drinks

To date, there’s been minimal research on the direct link between collagen supplements and weight loss. Most studies are small, outdated, or involve animals.

Although more research is needed, existing studies on the broader benefits of collagen show how these supplements may indirectly help with your weight loss goals:

Promote satiety

Collagen supplements may increase satiety, or the feeling of fullness. This could aid weight loss and management by reducing hunger, and therefore, how many calories you eat in a day.

Collagen might have this effect because it’s a protein. According to a 2020 review, high-protein diets increase satiety hormones like glucagon-like peptide-1 and cholecystokinin. They also suppress ghrelin, a hunger hormone.

According to a 2008 study, increased protein intake can also increase thermogenesis, which influences satiety and energy expenditure. The study also notes that higher protein diets may stimulate muscle protein anabolism, “favoring the retention of lean muscle mass while improving metabolic profile.”

Also, in a small 2009 study, gelatin was found to reduce hunger 44 percent more than casein, the protein in milk.

It’s worth noting that gelatin is an incomplete protein, meaning it lacks all the amino acids the body needs. You can’t meet your protein needs with gelatin or collagen supplements alone. But supplements can increase your overall protein intake, potentially improving satiety.

Increase muscle mass

Building muscle is an essential component of weight loss. That’s because muscle burns more calories at rest, increasing overall calorie expenditure.

Taking collagen supplements may help your efforts by increasing muscle mass. Remember, collagen is the main structural protein in your muscles.

In a 2015 study involving older adults, participants with sarcopenia (age-related muscle loss) completed 12 weeks of weight training. Half of the participants took collagen peptide supplements, while the other half took a placebo.

Those who took collagen peptides experienced a greater improvement in muscle mass and strength. They also lost more fat mass than the placebo group.

These results suggest that collagen supplements can support loss of body fat by enhancing the effects of weight training on muscle mass.

Reduce fat accumulation

There’s some evidence that collagen may reduce the development and accumulation of adipocytes, or fat cells.

A 2019 study found that collagen from skate, a type of fish, reduces body fat in humans. The amount of fat lost was small, but suggests potential benefits for weight loss.

Similarly, in a 2018 animal study, collagen peptides from skate had an anti-obesity effect in mice. The researchers linked this effect to improved fat metabolism and reduced fat accumulation.

A 2016 animal study also found that collagen hydrolysate (also called collagen peptides) reduced fat cell size and weight gain in rats.

Relieve joint pain

Collagen supplements might indirectly help weight loss by reducing joint pain. Healthy joints are needed to move comfortably during exercise and daily activities. Engaging more regularly in physical activity could then in turn support weight management.

A 2015 study found that collagen peptides can manage osteoarthritis. Osteoarthritis happens when your joint cartilage wears down, causing joint pain and stiffness.

Also, in a 2017 study involving athletes, collagen peptides decreased knee joint pain related to physical activity.

If joint pain prevents you from working out, these benefits of collagen may help.

Collagen supplements has other potential health benefits. Collagen may:

• improve skin elasticity
• reduce appearance of skin wrinkles
• increase skin hydration
• reduce bone loss
• improve brittle nails
• boost hair health
• support heart health

Research on the negative side effects of collagen supplements is lacking. But according to anecdotal reports, collagen supplements might cause side effects like:

• feeling of fullness
• heartburn
• bad taste in mouth

Also, like other supplements, collagen supplements aren’t regulated by the FDA. This means that the agency can’t speak to how safe or effective they are.

In turn, it’s difficult to know if a collagen supplement contains the ingredients it claims to have. It’s also possible that collagen supplements may contain:

• heavy metals (like cadmium)
• allergens (like hydrolyzed collagen from fish)
• microbial contaminants
• different doses than listed on the label

When purchasing supplements look for products that contain a USP Verified Mark on the label. This mark indicates that the product:

• contains the ingredients listed on the label
• doesn’t contain harmful contaminants
• will break down and be absorbed by the body within a specified amount of time
• has been made according to the FDA’s Current Good Manufacturing practices (CGMPs)

Collagen supplements might indirectly promote weight loss by:

• increasing satiety
• regulating fat metabolism
• increasing the effect of resistance training on muscle mass

Collagen supplements could also relieve joint pain, making it more comfortable to exercise.

But collagen supplements aren’t a magic bullet or a substitute for healthy habits. For sustainable weight loss, it’s still important to eat well, exercise regularly, and get enough sleep.

If you want to try taking collagen supplements for weight loss, use them as part of a holistic regimen, rather than as a replacement for healthy habits. It’s also a good idea to talk with a doctor to ensure collagen supplements are safe for you.