What collagen is
Collagen is the most abundant protein in the body. It gives structure to skin, bone, tendons, ligaments and cartilage. Researchers have named 28 types; type I makes up about 90% of the body's collagen, and type II is found in the cartilage that cushions joints.
Your body makes less collagen with age, and sun exposure, smoking, heavy drinking, poor sleep and low activity speed that loss. Collagen in food comes only from animal parts with connective tissue, such as tough cuts of meat, fish skin and bone broth.
Collagen peptides vs gelatin
| Form | What it is | Notes |
|---|---|---|
| Gelatin | Collagen cooked out of bones, cartilage and skin, then cooled so it sets | Used in food; gels in liquid |
| Collagen peptides (hydrolyzed collagen) | Collagen broken down further into small pieces | Dissolves in drinks; the form studied in the 2023 skin review below |
| Bone broth | Long-simmered bones and connective tissue | Amount of collagen varies; marketing claims outrun the evidence |
Collagen peptides are food-derived protein fragments sold as a supplement. They are not the same thing as the injectable products sold as peptide therapy, and evidence for one says nothing about the other.
What the evidence shows
- Skin hydration and elasticity: modest evidence. A 2023 review of 26 randomized trials with 1,721 people found hydrolyzed collagen improved skin hydration and elasticity compared with placebo, with better hydration results after more than 8 weeks. The authors noted mixed products, small trials and risk of bias, and called for large trials.
- Wrinkles: unclear. That review did not pool wrinkle results, so it can't say collagen smooths wrinkles.
- Joint pain: limited evidence. Cleveland Clinic rates collagen peptides possibly effective for pain and function in knee osteoarthritis, and Harvard notes some trials found less joint pain. Evidence for other joint problems is thin.
- Bone, hair and nails: the sources we reviewed show no good human evidence.
Funding matters here. Harvard's Nutrition Source notes that most, if not all, collagen supplement research is funded or partly funded by related industries, which makes the true effect hard to judge.
Safety and quality
- Side effects: trials haven't shown clear harms in people taking collagen supplements.
- Regulation: FDA does not approve dietary supplements for safety or effectiveness before they are sold. The maker is responsible for what's in the bottle.
- Contaminants: Harvard notes concern about heavy metals in some collagen products and bone broths. A third-party testing seal on the label is one way to check quality.
- Allergies: if you are allergic to fish or another animal source, check where the collagen comes from.
- Pregnancy, breastfeeding, kidney disease or a protein-restricted diet: ask your clinician first.
What supports your own collagen
Advice from Cleveland Clinic and Harvard for keeping collagen is mostly lifestyle: eat enough protein, get vitamin C, zinc and copper from food, protect your skin from the sun and don't smoke. A supplement may add a modest benefit on top of those basics, not replace them.
If you decide to try collagen, give it more than 8 weeks and judge it on something you can see or feel. Gabriel can answer questions about a product's label for free, and Gabriel Plus members get member prices on supplements.
Common questions
Do collagen supplements actually work?
For skin hydration and elasticity there is modest evidence from many small, often industry-funded trials. For knee osteoarthritis pain the evidence is limited. For wrinkles, hair and bone, it is weak or unclear.
Are collagen peptides better than gelatin?
Collagen peptides are collagen broken into smaller pieces, which dissolve easily and are the form studied in the 2023 skin review. Gelatin is less broken down. Both are digested into amino acids.
How long does collagen take to work?
Trials run for weeks to months. In a 2023 review, skin hydration results were better after more than 8 weeks than after shorter use.
Are collagen supplements safe?
Trials haven't shown clear harms, but FDA doesn't review supplements before they are sold, and some products may carry heavy metals. Choose a third-party tested product and check the animal source if you have allergies.
Is collagen the same as peptide therapy?
No. Collagen peptides are a food-derived supplement. Peptide therapy refers to other products, many injected, with different evidence and safety questions.
Sources
- Collagen Harvard T.H. Chan School of Public Health, The Nutrition Source
- Collagen Cleveland Clinic
- Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis (Pu et al., 2023) Nutrients
- Questions and Answers on Dietary Supplements U.S. Food and Drug Administration
This guide is general information, not medical advice. It does not replace a visit with a licensed clinician. Gabriel membership is not health insurance.