Internal hydration — The Dossier — VECHÉN

What hard water does

London has some of the hardest water in the UK. Hard water — water with a high mineral content, primarily calcium and magnesium — disrupts the skin's surface barrier. It strips away the natural lipids that keep water from evaporating from the epidermis, a process called transepidermal water loss (TEWL).

This is why people who move to London often notice their skin becoming drier. It is not a coincidence. The water is actively compromising the skin's ability to retain surface moisture. Most people respond by using more moisturiser. The moisturiser replaces what the water strips. It is an effective but ongoing intervention.

What I discovered — through supplementing and then through understanding the mechanism — is that the deeper internal hydration system is largely unaffected by hard water. It operates below the surface. And when that system is working properly, the demand for surface intervention decreases.

Transepidermal water loss (TEWL)

TEWL is the passive evaporation of water through the skin's surface. It increases when the skin barrier is compromised — by hard water, harsh cleansers, cold weather or UV exposure. Most moisturisers work by either occluding the surface (preventing evaporation) or humectants that draw water to the surface. Neither addresses the dermal reservoir.

The collagen mechanism

Collagen is the most abundant protein in the human body, comprising approximately 30% of total protein mass. In skin, it makes up roughly 75% of the dry weight of the dermis. Its production peaks in your mid-twenties and declines at roughly 1% per year after that.

When you supplement with hydrolysed marine collagen peptides, the peptides are absorbed through the intestinal wall — at 2000 Dalton molecular weight, they are small enough to cross intact — and enter systemic circulation. They reach the dermis, where fibroblasts detect them as a signal that collagen is degrading and upregulate production in response.

More collagen in the dermal matrix means a denser structural scaffold. A denser scaffold retains more hyaluronic acid. More hyaluronic acid means more water held internally. The skin is literally better at holding onto moisture because the structure that holds moisture is more robust.

This is not a topical effect. It is not a temporary plumping from surface application. It is structural — and it accumulates over time.

Why hyaluronic acid in a supplement works differently

Hyaluronic acid applied topically can only penetrate to the surface layers of the epidermis. The molecules are too large to reach the dermis through the skin barrier. This is why topical HA gives an immediate surface plumping effect — it is working in the epidermis, not the dermis.

Oral hyaluronic acid, taken at a sufficient dose, enters the bloodstream and reaches the dermis directly. Research supports its role in contributing to dermal hydration from within — reinforcing the extracellular matrix and improving the skin's internal moisture-retaining capacity.

STRUCTURA contains 120mg of hyaluronic acid per serving. Combined with 10,000mg of marine collagen peptides, the formula addresses both the structural scaffold (collagen) and the water-retaining component (hyaluronic acid) of the dermal matrix simultaneously.

"Not because you are being more disciplined with your routine. Because your skin needs less intervention from the outside."

What actually changes

The change is not dramatic. It is cumulative and structural, which means it builds gradually and holds. Most people who use STRUCTURA consistently report noticing a difference in their routine at around 28 days — not in their skin in isolation, but in what their skin needs.

They reach for their moisturiser less frequently. They need less product when they do use it. Their skin recovers faster after exposure to hard water, cold air, or long-haul flights. These are not marketing claims — they are the predictable consequences of a dermal matrix that is better equipped to hold water internally.

The practical upshot is real. A well-functioning internal hydration system reduces dependence on topical products. Over time, that means a simpler routine, less money spent on skincare, and less time spent applying it. Not because you are cutting corners — because your skin no longer needs the same level of external support.

A note on what this is not

This is not a claim that collagen supplementation replaces skincare. A good SPF, a barrier-supporting cleanser, and targeted treatments all have their place. Nor is it a claim that results are instant or guaranteed — individual absorption, consistency, and diet all play a role.

What it is is a mechanism. An evidence-based explanation for why, when the dermal matrix is properly supported from within, the demand for external intervention decreases. The skin becomes better at doing what it is designed to do — hold water, maintain structure, and resist daily stressors.

That is what STRUCTURA is built around. Not a topical fix. A structural foundation.