Your skin loses water constantly. It's called transepidermal water loss (TEWL), and managing it is one of the most important functions your skin performs.
A healthy skin barrier keeps that water loss in check. A compromised barrier lets moisture escape, leaving skin dry, reactive, and vulnerable. Understanding how aloe vera supports this barrier function explains why the plant has been prized for skin hydration across every culture that encountered it.
The Barrier That Holds Everything Together
Your skin barrier—technically called the stratum corneum—is like a brick wall made of skin cells (the bricks) held together by lipids (the mortar). When this barrier is intact, it keeps moisture in and irritants out. When it's compromised, water escapes and external substances can penetrate, leading to dryness, sensitivity, and inflammation.
Transepidermal water loss is the measurement of how much water passes through your skin and evaporates. Higher TEWL indicates a compromised barrier; lower TEWL suggests a healthy, functional one.
Research has demonstrated that aloe vera supports this barrier function through multiple mechanisms—not just by sitting on top of skin as an occlusive, but by actually supporting the biological processes that maintain barrier integrity.
The Clinical Evidence for Barrier Support
A double-blind, randomized, placebo-controlled study from Wakayama Medical University examined aloe sterol's effects on skin barrier function over 12 weeks.
The results were significant: participants taking aloe sterol showed reduced transepidermal water loss compared to the placebo group. Their skin was literally holding onto moisture more effectively.
But TEWL reduction wasn't the only finding. Researchers also documented:
- Increased skin hydration levels
- Improved collagen scores on ultrasonography
- Enhanced overall skin condition assessments
A previous study using a higher dose of aloe sterol (40 μg) had shown similar results, with significant increases in skin barrier function, moisture, and elasticity. Interestingly, even the lower-dose study (19 μg) achieved comparable improvements in TEWL, suggesting the barrier-supporting effects are achievable at various supplementation levels.
How Aloe Supports Hydration: The Mechanisms
Aloe vera isn't just coating your skin with moisture—it's supporting the systems that keep moisture where it belongs.
Polysaccharide Hydration: Aloe vera gel is approximately 95-99% water, but the remaining percentage contains polysaccharides that act as natural humectants. These compounds, particularly glucomannan and acemannan, bind water molecules and help maintain hydration within the skin.
Research published in the Indian Journal of Dermatology describes how mucopolysaccharides in aloe help "bind moisture into the skin." This isn't just surface-level hydration—it's supporting the skin's own moisture-retention capacity.
Hyaluronic Acid Synthesis: As discussed in our article on fibroblast function, aloe vera stimulates increased synthesis of hyaluronic acid in skin tissue. Hyaluronic acid can hold up to 1,000 times its weight in water, making it one of the most effective natural hydrating compounds.
Barrier Repair Support: Aloe's anti-inflammatory properties help calm the irritation that often accompanies barrier damage. By reducing inflammation, aloe creates conditions where barrier repair can occur more effectively.
Lipid Support: Research has identified that aloe vera contains fatty acids and sterols that may contribute to the lipid matrix of the skin barrier. This means aloe isn't just adding moisture—it may help maintain the structural components that prevent moisture loss.
What the Research on Dry Skin Shows
The Japanese clinical studies included particularly interesting subgroup analysis: among participants with dry skin specifically, the improvements in skin hydration were even more pronounced.
This suggests that aloe vera may be especially beneficial for people whose skin barrier is already somewhat compromised—exactly the population that struggles most with moisture retention and sensitivity.
It's also consistent with traditional uses of aloe vera across cultures. People have historically reached for aloe when their skin was dry, damaged, or stressed—conditions characterized by barrier compromise. The modern research validates what generations observed: aloe helps when skin can't hold onto moisture.
The Fresh Aloe Advantage
Here's where the connection to quality matters.
A clinical summary from Mayo Clinic notes that aloe-based creams may help relieve dryness and support moisture retention without clogging pores. But the key word is "aloe-based"—not just "aloe-labeled."
The bioactive polysaccharides that support barrier function and hydration are sensitive to processing. Improperly handled aloe—degraded by heat, improper extraction, or extended storage—may not deliver the same benefits that research has documented.
When an ingredient list says "aloe vera," that tells you a botanical was included. It doesn't tell you whether the processing preserved the compounds that make aloe effective. This is why we're particular about sourcing for every Artisan formula.
The Practical Difference for Different Skin Types
Understanding aloe's barrier-supporting mechanisms helps explain its broad applicability:
For dry skin: The combination of humectant polysaccharides, hyaluronic acid stimulation, and barrier-supporting effects addresses multiple factors contributing to dryness.
For sensitive skin: By supporting barrier integrity while providing anti-inflammatory benefits, aloe helps sensitive skin become more resilient without triggering reactions.
For athletic skin: Sweat, friction, and environmental exposure stress the skin barrier. Aloe's support for barrier repair helps active skin recover from the demands of training.
For aging skin: Reduced barrier function is one characteristic of aging skin. Aloe's support for barrier integrity helps address one factor in age-related dryness.
Beyond Surface Hydration
Most moisturizers work by sitting on the skin surface and preventing water evaporation (occlusion) or by drawing water into the skin from the environment (humectancy). These are temporary effects that last until the product is washed off or absorbed.
What makes aloe vera interesting is the evidence that it actually supports the skin's own barrier-maintenance systems. By stimulating fibroblast activity, increasing hyaluronic acid synthesis, and supporting the structural components of the barrier, aloe may help skin become better at retaining moisture on its own—not just while the product is present.
This is the difference between treating a symptom and addressing an underlying mechanism. It's also why aloe has remained relevant across 6,000 years of skincare—because it doesn't just mask dryness, it supports the systems that prevent dryness in the first place.
On our Washington State farm, this is the kind of ingredient science we look for. Not just what an ingredient does on the surface, but how it supports the deeper processes that determine skin health. The organic aloe in every Artisan formula is there because the research supports what generations of human observation discovered: aloe genuinely helps skin hold onto moisture.
