What Are the Main Proteins of the Skin?
The main proteins of the skin are three: collagen, elastin and keratin. Collagen gives structure and firmness, elastin allows the skin to stretch and come back, and keratin forms the protective barrier of the outermost layer. All three are produced inside your body, and all three start being produced less with age.
Here is the clarification that puts everything that follows in order, because a lot of wrong information circulates about this: you cannot eat elastin and get elastin, nor eat keratin and get keratin. What you eat is broken down into amino acids, and your body uses them as raw material to manufacture its own proteins. What you can do is make sure that raw material is not missing —and, in the case of collagen, provide peptides that really do reach circulation.
How the skin is built
The skin is the largest organ in the body and it has three layers.
- Epidermis: the outer layer. Its most superficial part, the stratum corneum, is made up of cells that no longer have a nucleus, rich in keratin. It is your barrier against the outside.
- Dermis: the middle layer, and where almost everything is decided. That is where the fibroblasts live, the cells that manufacture collagen and elastin, along with blood vessels and sweat and sebaceous glands.
- Hypodermis: the deepest layer, made up above all of fatty tissue, which cushions and insulates.
The three main proteins of the skin
Collagen: the structure
It is the most abundant protein in the skin and accounts for about 75% of the dry weight of the dermis. It works as the scaffolding: it gives firmness, thickness and resistance.
You start producing less collagen at around 25 years of age, at a rate of approximately 1% per year, and the decline accelerates with menopause. When the scaffolding thins out, wrinkles and sagging appear. You can read the detail in at what age you start losing collagen and in what hydrolyzed collagen is.
Elastin: the rebound
If collagen is the structure, elastin is the spring. It is what allows you to pinch your skin and have it go back into place immediately.
And it has an inconvenient particularity: elastin is produced above all during development, and the adult body replenishes very little of it. Its turnover is extremely slow compared with that of collagen. That is why accumulated elastic damage —above all from the sun— is so hard to reverse, and that is why protecting is worth more than repairing. More on this in why the skin loses elasticity.
Keratin: the barrier
Keratin is a fibrous, hard protein that forms the protective layer of the epidermis, and also hair and nails. Its job is to waterproof and defend: it holds water in and keeps irritants and microorganisms out.
Other proteins that also count
Besides the three main ones, the skin depends on enzymes, which direct the chemical reactions of cell renewal, and on antibodies, which are part of the skin's immune defense. Also on fibrillin and the laminins, which act as supporting scaffolding between layers.
What to eat to support the skin's proteins
Here is the important correction that gets repeated across half the internet.
There is no food "rich in elastin" or "rich in keratin" that provides you with those proteins already formed. Your digestive system takes apart any protein you eat until it turns it into amino acids, and from there your body builds what it needs. What does matter is giving it the right bricks:
- Complete protein: egg, fish, chicken, meat, dairy, legumes. They provide glycine, proline and lysine, the amino acids collagen is made with.
- Vitamin C: essential. Without it, collagen synthesis simply does not complete. It is in guava, citrus, peppers and kiwi.
- Zinc and copper: cofactors of the enzymes that assemble collagen and elastin. In seeds, shellfish and nuts.
- Sulfur: key for keratin. In egg, garlic, onion and cruciferous vegetables.
And a note on gelatin and bone broth: they do provide collagen, but in the form of large molecules and in a highly variable amount. They are a contribution, not a strategy.
Why collagen creams do less than they promise
This part is worth saying head-on even if it is not what people want to hear.
The collagen molecule is too large to cross the stratum corneum. A collagen cream hydrates the surface and feels good —that is real— but the collagen does not reach the dermis, which is where the problem lives. The same applies to elastin and keratin in topical format.
Put plainly: collagen is taken, not rubbed on. For it to reach the dermis it has to travel through the blood.
And there the route decides everything
If collagen has to arrive through circulation, the question is how much really arrives. The answer depends on the path:
| Route | Approximate absorption |
|---|---|
| Sublingual | 80% |
| Vaginal | 99% |
| Oral (capsule or powder) | 25% |
| Topical (cream) | Does not reach the dermis |
Collagen is a protein and the digestive system is made to take proteins apart: that is why a capsule or a powder leaves about 25%. By the sublingual route, with low molecular weight peptides that cross the oral mucosa and avoid the stomach and the liver, the figure rises to around 80%. More than three times the difference with the same product.
The Liquid Collagen Boost from The Everyday Lab is formulated for that route: 150 mg of hydrolyzed collagen per 1.5 mL serving (30 drops) taken under the tongue, with no powders and nothing to mix. The combination —hydrolyzed collagen in small peptides and the sublingual route, which avoids digestion— is what takes its absorption up to 80%, about 3 times a capsule. The full comparison is in sublingual collagen vs. capsule and in science and absorption.
What no supplement does
- It does not replenish elastin. No supplement regenerates it significantly in an adult. That is why sunscreen is the best anti-aging investment there is.
- It does not make up for sun damage. Ultraviolet radiation degrades collagen faster than any intake replenishes it.
- It does not act within days. The realistic time frame to notice changes in the skin is around 6 weeks: the time of one skin renewal cycle.
- It does not cure, treat or prevent diseases. It is a food supplement, not a medicine.
In summary
The main proteins of the skin are collagen (structure), elastin (elasticity) and keratin (barrier). They are not eaten or rubbed on: they are manufactured inside the body from amino acids, vitamin C and minerals. The only one of the three you can contribute to directly in a useful form is collagen, and only if it reaches circulation: 80% by the sublingual route versus 25% for a capsule. Everything else —sunscreen, enough protein, sleep— remains the foundation, and no bottle replaces it.
Sublingual collagen from The Everyday Lab
The Liquid Collagen Boost
Sublingual collagen with 80% absorption. It arrives through circulation all the way to the dermis, which is where collagen is needed.
See the Collagen Bundle (sublingual + vaginal)
This content is informational and does not replace medical or dermatological consultation. Food supplements are not medicines: they do not cure, treat or prevent diseases. If you have a diagnosed skin condition, discuss it with your dermatologist.
About The Everyday Lab: Learn the story, absorption technology and full product range in The Everyday Lab's media coverage.