Collagen is the most abundant protein in the human body. It forms much of the structure of skin, tendons, bones and connective tissue, and the body builds it continually from the amino acids in your food. Production slows as we age, which is the starting point for most of the marketing you see.
What marine collagen is
Marine collagen is extracted from fish, usually the skin and scales. It is mostly type I collagen, the same type that dominates human skin. Manufacturers break it down into smaller pieces known as hydrolysed collagen or collagen peptides, which dissolve easily and can be added to powders and gummies.
What happens after you swallow it
Collagen does not travel intact from your stomach to your face. As the Harvard T.H. Chan School of Public Health explains, digested collagen is broken down into amino acids, which the body distributes wherever it needs protein. Some short peptides have been detected in the blood, and researchers are investigating whether they act as signals for the cells that make collagen. That idea is interesting, but it has not been settled.
What the research says, and where it stops
A systematic review and meta-analysis published in the International Journal of Dermatology in 2021 pooled 19 randomised, placebo-controlled trials of oral hydrolysed collagen with 1,125 participants, almost all of them women. Taken together, the trials favoured collagen over placebo for measures of skin hydration, elasticity and wrinkles after around 90 days of use. That is a real finding, but several limits apply:
- Many of the individual trials were small and short
- Harvard notes that most collagen research is funded fully or partly by related industries, or involves authors with industry ties
- Doses and products varied, so results are hard to compare and to apply to any one product
- Long-term data are scarce
- Evidence for hair and nails is thinner still, and Harvard describes research on direct benefits as limited
So a fair summary is that the evidence is promising in places and limited overall. Collagen should not be expected to reverse ageing, and nobody can promise you visible results.
What makes a clearer difference
Harvard also warns that relying on supplements can distract from the habits that protect collagen, such as sleep and not smoking. The basics have much stronger support when it comes to looking after your skin:
- Sunscreen and shade, especially given the strong sun in Jordan
- Not smoking, including shisha
- Enough protein from eggs, chicken, fish, lentils and yoghurt, which supply the amino acids used to build collagen
- Vegetables and fruit rich in vitamin C, such as peppers, parsley and oranges
- Good sleep
Who should be careful
Anyone with a fish allergy should avoid marine collagen unless a doctor says otherwise. If you are pregnant or breastfeeding, have kidney disease, are on a protein-restricted diet or take regular medication, ask your doctor or pharmacist first. See a dermatologist about any skin change that worries you, such as a mole that grows or changes colour.
Sources
- Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis · International Journal of Dermatology
- Collagen · Harvard T.H. Chan School of Public Health, The Nutrition Source
This article is general health information for educational purposes and is not medical advice. It does not promote any product. Talk to your doctor or pharmacist before starting a supplement, especially if you are pregnant, breastfeeding, have a health condition or take medication.