Type I and III collagen: differences and role in aging
Quick facts
- Type I
- Most abundant collagen in adult dermis; provides strength and firmness.
- Type III
- Thinner fibers, more common in young skin and in the early stage of healing.
- With age
- Production drops and fibers fragment; the ratio between the types changes.
- In HOF
- Biostimulators aim to activate fibroblasts to stimulate collagen production.
Collagen is the main structural protein of the skin. There are dozens of types, but two are the most cited in the dermis: type I and type III. Together they form the network that holds the skin up and accounts for firmness and strength.
What is the difference between the two?
| Feature | Type I | Type III |
|---|---|---|
| Fiber | Thick, strong | Thin, more delicate |
| Predominance | Adult dermis, most of the collagen | Young skin, vessels and early healing |
| Function | Firmness and resistance to tension | Flexibility and support of the matrix as it forms |
In healing, type III usually appears first and is later replaced by type I, which gives the tissue more strength.
What changes with age?
Fibroblasts, cells of the dermis that produce collagen and elastin, become less active. Existing fibers break down faster than they are replaced. The result shows in the skin as loss of firmness, thinner texture and static wrinkles. Chronic sun exposure (photoaging), smoking and other factors speed up the breakdown. The extracellular matrix that supports the cells also reorganizes.
How does HOF relate to this?
Collagen biostimulators are not collagen: they activate fibroblasts to produce the patient's own collagen, in a process called neocollagenesis. The effect is gradual and usually takes more than one session, at the professional's discretion. Microneedling also triggers skin repair.
In Harmy
Harmy projects the appearance of volume in marked areas and does not simulate collagen response over time. For biostimulators, the gradual evolution is part of the conversation in the consultation, and the projection is only illustrative.
Frequently asked questions
What is the difference between type I and type III collagen?
Type I forms thick, strong fibers and predominates in adult dermis. Type III forms thinner fibers and is more common in young skin and in early healing.
Does collagen decrease with age?
Yes, production drops with aging and the fibers break down more. Sun, smoking and other factors speed up this process.