3. Collagen Smooths Wrinkles and Boosts Elasticity in Skin
Skin health is collagen's most well-researched benefit, says Lachman. In one review, researchers analyzed 11 randomized placebo-controlled studies of more than 800 patients who took up to 10 grams (g) per day of collagen with the goal of improving skin health.[4] The results? The supplements were shown to improve skin elasticity, help it better hold onto moisture, and increase the density of collagen fibers within skin. 
Another review and meta-analysis on 14 randomized controlled trials on about 1,000 people also supported the idea that hydrolyzed collagen could improve skin hydration and elasticity across a variety of sources of collagen (including bovine, chicken, and fish) at even lower doses — 0.3 milligrams (mg) to 5 g daily for at least four weeks.[5] It could be a small step in preserving a youthful appearance.

4. Collagen May Relieve Joint Aches and Pains
Joint pain can make it difficult to exercise, which can knock you off track in meeting your fitness goals. A collagen supplement may help you stay the course. “There is some evidence that collagen can be great for supporting connective tissues and improving joint pain after exercise,” says Angelone. 

For instance, one study found that athletes with knee pain who took 5 g of collagen peptides daily for 12 weeks had less joint pain during exercise than a placebo group.[6] Oral collagen may support cartilage repair and may also have an anti-inflammatory effect.
Collagen

5. Oral Supplements May Promote Gut Health
In inflammatory digestive conditions, such as inflammatory bowel disease (IBD), there is a “gut healing” theory about collagen. “Some research finds that collagen levels are decreased in patients with these conditions. By taking collagen, you would help correct a deficiency,” says Lachman.

Research found that among IBD patients, there was an imbalance between the formation and breakdown of collagen fibers, and this was connected to inflammation.[7] A study also showed that IBD patients have decreased serum levels of type 4 collagen. Collagen is a part of connective tissue, which makes up your colon and GI tract, so by bringing your levels up, there may be a supportive environment for your body to heal.[8] This is an emerging idea, Lachman says, but it may be one benefit to trying a supplement or dietary approach to increase collagen intake.
And for some healthy people, an oral collagen supplement may also help improve GI symptoms. When women were asked why they took collagen, they reported that it helped with digestion, kept bowel movements regular, and decreased bloating, among other perceived perks.[9]
Since collagen may contribute to these symptoms for some people, it’s important to keep track of how you feel when taking it and make adjustments to how much, when, or if you take it as needed. Remember to talk to your healthcare provider before trying any supplements. 

6. Peptides Can Keep Bones Healthy
Bone mineral density decreases as you age, especially after menopause.[10] In a randomized, placebo-controlled, double-blind trial of 102 post-menopausal women, participants who took collagen peptides for one year increased their bone mineral density compared with the control group.[11] The researchers postulated that this was because the collagen stimulated bone formation while slowing down bone loss, although more research is needed, and it’s important to use other measures beyond collagen to support skeleton health, such as exercise like resistance training.[12]
7. Collagen May Be Useful in Joint Disease
There are different types of collagen.[13] Type 1 (found in beef) is beneficial when it comes to your skin, while type 2 (found in chicken) is potentially more helpful when it comes to arthritic joint pain, Lachman explains. Joints are composed of cartilage, which is largely made up of collagen. 
A study found that patients with knee osteoarthritis who took acetaminophen along with type 2 collagen reduced joint pain during walking and had quality of life superior to those on the alone.[14] That said, research is mixed and hasn’t come to a firm conclusion. Lachman says your best bet is to purchase a supplement that contains various sources of animal collagen for the widest range of benefits.
The Takeaway
Collagen is a key protein that aids in essential bodily functions. There's some supporting evidence that adding collagen to your diet can help improve skin elasticity and bolster joint and bone health, but more high-quality research is needed. If you're considering collagen supplements, discuss them with your healthcare provider and be aware of some reported side effects, including a rash and — in rarer cases — liver problems. Look for quality sources such as bone broth or powders.