Collagen is one of the best-selling supplements in the U.S. The research is more encouraging than for many products, but it’s also smaller and more industry-funded than the marketing suggests.
The evidence in brief
- Collagen supplements are broken down into amino acids and small peptides during digestion; they don’t travel intact to your skin.
- Several small trials and pooled analyses report modest improvements in skin hydration and elasticity over two to three months, but many studies are funded by manufacturers.
- Evidence for joint pain is mixed, and collagen isn’t a substitute for treatment of arthritis.
- Sun protection and not smoking do more to protect your skin’s own collagen than any supplement.
Collagen is the most abundant protein in your body, giving structure to skin, tendons, bones and cartilage. From your mid-twenties on, your body gradually makes less of it, and sun damage and smoking speed up the loss. It’s easy to see why the idea of topping it up from a scoop of powder is appealing.
How collagen supplements work
Most products contain hydrolyzed collagen, also called collagen peptides, made from cattle, pigs or fish. Your digestive system breaks it down like any other protein, into amino acids and short peptides. The theory is that some of those peptides signal skin and joint cells to make more of their own collagen. It’s a plausible idea with some laboratory support, but it isn’t the same as the supplement rebuilding your skin directly.
What the trials show
Skin. A number of randomized trials, mostly lasting eight to twelve weeks, report small improvements in skin hydration and elasticity compared with placebo. Pooled analyses of these trials reach similar conclusions. The caveats:
- Many studies are small.
- A large share are funded by companies that sell collagen.
- Results for wrinkles are less consistent than for hydration.
- We know little about long-term effects.
Joints. Studies on joint pain, including in people with osteoarthritis and athletes, are mixed. Some show modest pain relief; others show little difference from placebo. If you have arthritis, collagen isn’t a replacement for treatment from your doctor.
What protects the collagen you already have
| Habit | Why it matters |
|---|---|
| Daily broad-spectrum sunscreen | UV light breaks down collagen and is the main cause of visible skin aging |
| Not smoking | Smoking damages collagen and the blood supply to skin |
| Enough protein and vitamin C in your diet | Raw materials your body uses to make collagen |
| Sleep and managing stress | Support general skin health |
Worth knowing
None of these are as exciting as a new powder, but each has far more evidence behind it.
If you decide to try it
- Choose a product with independent testing, such as a USP or NSF seal, so you know what’s inside.
- Check the source if you have allergies or dietary restrictions.
- Give it a fair trial, usually a couple of months, and judge honestly whether you notice a difference.
- Watch the extras. Some products add vitamins, herbal ingredients or sweeteners you may not want.
Supplements are sold under different rules from medicines. Our guide to reading wellness claims explains what a label can promise. And if you’re comparing collagen with other skin trends, see our look at red light therapy at home.
Asked and answered
Is marine collagen better than bovine collagen?
There’s no strong evidence that one source works better. Marine collagen is an option for people who avoid beef or pork, but it isn’t suitable for people with fish allergies.
Do I need to take vitamin C with collagen?
Your body needs vitamin C to make collagen, but most people get enough from food. A balanced diet with fruit and vegetables covers it.
Are collagen supplements tested by the FDA?
No. Dietary supplements don’t need FDA approval before they’re sold. Look for independent testing seals, such as USP or NSF, to check that a product contains what it says.
This guide is general information, not medical advice. Check with your doctor or pharmacist before starting a supplement, device or treatment, especially if you’re pregnant, take medicines or have a health condition.