The Claim

Topical application of retinol and retinoic acid is associated with long-lasting upregulation of epidermal barrier proteins (filaggrin, involucrin, and calmodulin-like protein 3) and downregulation of transglutaminase 1 and 3, indicating persistent remodeling of the skin’s outermost protective layer.

Source: One-year longitudinal study of the stratum corneum proteome of retinol and all-trans-retinoic acid treated human skin: an orchestrated molecular event

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
27score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

Topical retinol and retinoic acid change the expression levels of specific skin barrier proteins and enzymes in a sustained manner, resulting in structural alterations to the outermost layer of the skin.

See the scientific wording

Topical retinol and retinoic acid are associated with long-lasting upregulation of epidermal barrier proteins—including filaggrin, involucrin, and calmodulin-like protein 3—and downregulation of transglutaminase 1 and 3, suggesting a persistent remodeling of the skin’s outermost protective layer.

Why this might work

When retinol or retinoic acid is applied to the skin, it triggers a chain of events inside skin cells: energy production increases to fuel repair, protein-making machinery turns on to build new barrier proteins, the cell skeleton rearranges to support structural changes, and enzymes that break down signaling molecules are turned off. This causes the skin to produce more filaggrin, involucrin, and calmodulin-like protein 3 while reducing transglutaminase enzymes that cross-link proteins, resulting in a thicker, more organized, and longer-lasting protective outer layer.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: One-year longitudinal study of the stratum corneum proteome of retinol and all-trans-retinoic acid treated human skin: an orchestrated molecular event

    This study found that using retinol or retinoic acid on your skin for a whole year changes the proteins in your outer skin layer in lasting ways, making it stronger and more organized over time.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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