Why TEWL Is the Key to Validating Barrier Repair Claims
In today’s skincare world, consumers are more educated than ever, and the demand for measurable results is reshaping how products are formulated, marketed, and tested. One claim in particular continues to gain traction with both beauty brands and dermatologists: “Improves barrier function” or “Reduces TEWL.”
But what does that mean? And how can brands clinically validate those claims? Let’s unpack the science behind barrier repair and TEWL, and whyit mattersr more than ever.
What Is the Skin Barrier and Why Does It Break Down?
The stratum corneum, the outermost layer of the skin, serves as the body’s first line of defense. It helps:
- Retain moisture
- Block out pathogens, allergens, and irritants
- Regulate skin pH and overall skin health
Everyday, aggressors like pollution, harsh cleansers, exfoliants, and even UV exposure can disrupt this barrier. When that happens, skin becomes vulnerable to:
- Dehydration
- Sensitivity
- Redness and inflammation
- Increased TEWL
What Is TEWL?
TEWL (Transepidermal Water Loss) is the amount of water that passively evaporates from the skin into the surrounding environment.
Higher TEWL = Compromised barrier
Lower TEWL = Healthy, intact barrier
TEWL is a gold-standard, objective biomarker of skin barrier function. It’s measured in grams per square meter per hour (g/m²/h).
How Is TEWL Measured in Clinical Testing?
At Orivida Research, we measure Transepidermal Water Loss (TEWL) using the Courage + Khazaka Tewameter®—a gold-standard, open-chamber probe that quantifies water evaporation from the skin's surface with high precision.
Our TEWL testing protocol typically includes:
Baseline measurement (before product application)
Controlled product application (e.g., moisturizer or serum)
Follow-up measurements at defined intervals (e.g., 30 minutes, 2 hours, 24 hours, or across several days)
By analyzing changes in TEWL values, we assess:
Immediate impact on barrier function
Cumulative skin improvement over time
Product efficacy versus placebo or untreated skin
What Claims Can Be Made with TEWL Data?
“Reduces TEWL by X% after several days”
“Improves barrier function after a single use”
“Clinically proven to reinforce the skin’s moisture barrier”
“Helps protect against environmental stressors and dehydration”
The Orivida Advantage: Fast, Focused, and Clinically Backed
At Orivida Research, we design TEWL-driven studies that are:
✅ Customizable — from single-use to long-term protocols
✅ Clinically rigorous — using the Courage + Khazaka Tewameter® for precise, instrument-verified results
✅ Credible — results you can trust, with clear clinical endpoints and transparent methodology
✅ Efficient — cost-effective and quick to launch, ideal for both pre-launch validation and post-marketing claims
Ready to Make a Claim Like “Clinically Proven to Reduce TEWL”?
Let’s talk. We help beauty and personal care brands bring meaningful, data-backed claims to market, without unnecessary complexity.
📩 Contact us at Hello@Orivida-Research.com