Collagen Intake Calculator

There is no officially established RDA for collagen because it is not an essential nutrient - the body synthesises its own. Clinical trials have used varying doses depending on the goal: 2.5-10 g/day for skin elasticity and hydration improvements; 10-15 g/day for joint health and osteoarthritis symptoms; and up to 15-20 g/day as part of athletic recovery protocols. Most studies use 10 g/day as a convenient mid-range dose.

The evidence is mixed. Some well-designed randomised controlled trials have found improvements in skin hydration, elasticity, and wrinkle depth with 2.5-10 g/day over 4-12 weeks. Studies on joint pain show modest but significant reductions in osteoarthritis symptoms at 10 g/day. However, the body digests collagen peptides like any other protein and does not preferentially route them to skin, joints, or cartilage. Vitamin C is required for the body's own collagen synthesis.

There are at least 28 types of collagen in the body. Type I (skin, bone, tendon) and Type III (skin, blood vessels) are most common in supplements. Type II (cartilage) is used in joint-specific products. Hydrolysed collagen (collagen peptides) has smaller molecular weight and is claimed to be better absorbed. Marine collagen comes from fish; bovine collagen from cow hides or bones. There is no consistent head-to-head evidence for superiority of any type.

Collagen is found in animal connective tissue: bone broth, pork skin (cracklings), chicken skin, fish skin, and cartilage-rich cuts. The body also synthesises its own collagen from glycine, proline, hydroxyproline, and vitamin C. Foods that support collagen synthesis include citrus fruits, strawberries, bell peppers (vitamin C sources), egg whites (proline), garlic (sulfur), and leafy greens.

Collagen supplements are generally considered safe for most adults. Some people experience mild digestive symptoms (fullness, heartburn). People with fish, shellfish, or egg allergies should check the source. Some marine collagen products contain heavy metals if sourced from contaminated waters. As with any supplement, collagen is not regulated to the same standard as medications. Always choose reputable brands with third-party testing.