Collagen has gone from a niche beauty product to a kitchen staple. You can find it in coffee creamers, protein bars, gummies, water bottles and powders that promise younger skin, healthier joints and stronger hair and nails. Some of these promises have a little research behind them. Many do not. Here is a clear look at what collagen supplements can and cannot do.
What collagen is
Collagen is the most common protein in your body. It forms the scaffolding of your skin, tendons, ligaments, cartilage and bones. As we age, we make less collagen, and the collagen we have becomes weaker. Sun exposure, smoking and high sugar intake speed this up. That is part of why skin wrinkles and sags and joints stiffen with age.
What is in a collagen supplement
Most collagen supplements are made from the skin, bones or scales of cows, pigs, chickens or fish. The most common form is hydrolyzed collagen, also called collagen peptides. The collagen has been broken down into small pieces that dissolve easily in drinks. Our page on collagen peptides explains the form in more detail.
You will see "types" on labels:
- Type I is found in skin, bone and tendons.
- Type II is found in cartilage, and is often sold for joints.
- Type III is found with type I in skin and blood vessels.
When you eat collagen, your body breaks it down into amino acids and small peptides, just like any other protein. It does not travel straight to your face. There is some evidence that certain peptides may signal your body to make more of its own collagen, but this is still being studied.
What the research shows
Skin
This is where the evidence is most promising. Several reviews of small studies found that taking hydrolyzed collagen for 8 to 12 weeks modestly improved skin hydration and elasticity, and in some studies, wrinkle depth. That is encouraging. But many of these studies were funded by collagen manufacturers, many were small, and the improvements were modest. Collagen will not undo sun damage. Sunscreen and not smoking remain far more powerful. See winter foods for healthy skin.
Joints
Some studies suggest collagen may ease joint pain in people with osteoarthritis and in athletes, but the results are mixed and the effect is small. It is not a substitute for exercise, weight management and the treatments your doctor recommends.
Muscle
Collagen is a protein, so it does count toward your daily protein. But it is an incomplete protein. It lacks tryptophan, one of the essential amino acids, and is low in leucine, the amino acid most important for building muscle. For muscle, whey, soy or a mixed plant protein is a better choice. Our comparison of collagen peptides vs protein powder explains the difference, and our protein powder buying guide can help you choose.
Hair and nails
The research here is thin. A few small studies suggest collagen might help brittle nails, but there is little evidence for hair growth.
Bones
A few studies have suggested a possible benefit for bone density in postmenopausal women, but it is too early to say. Calcium, vitamin D and exercise remain the foundation. See calcium and bone health.
Is it safe?
For most people, collagen is safe. Side effects are rare and usually mild, like a feeling of fullness or upset stomach. A few points to watch:
- Allergies. Marine collagen comes from fish, and some products come from shellfish or eggs. Check the label if you have allergies.
- Contaminants. Because collagen comes from animal parts, some products have tested positive for heavy metals in independent tests. Choosing a product with a third-party seal lowers this risk.
- Kidney disease. If you have kidney disease or must limit protein, talk to your doctor first.
- Pregnancy and breastfeeding. There is little research, so check with your doctor.
How to choose a collagen supplement
- Look for hydrolyzed collagen or collagen peptides for skin and general use.
- Check the dose. Studies for skin often used 2.5 to 10 grams a day.
- Choose a third-party tested product. See what third-party tested really means.
- Skip extras you do not need. Many products add biotin, hyaluronic acid or a proprietary blend, which raises the price. See proprietary blends explained.
- Check cost per serving. Collagen is often expensive per gram of protein. See how to calculate cost per serving.
- Be patient. Give it at least eight to twelve weeks before you judge.
Help your body make its own collagen
Your body makes collagen from the protein you eat. To support it:
- Eat enough protein from a variety of foods.
- Get plenty of vitamin C from fruits and vegetables. It is essential for collagen production. See orange juice vs vitamin C supplements.
- Wear sunscreen every day. UV light is one of the biggest causes of collagen breakdown.
- Do not smoke.
- Stay active. Exercise helps keep tendons and bones strong.
The bottom line
Collagen supplements may modestly improve skin hydration and elasticity, and may help some people with joint pain. They are safe for most people but are not a complete protein, so they are not the best choice for building muscle. If you try collagen, choose a tested product and give it a couple of months. For more, see our collagen ingredient page and the healthy aging goal page.