OpenHeim Independent Laboratories · Dermatology Research Division
Clinical & laboratory evaluation of the Julia filtered showerhead
A 12-week assessment of contaminant-removal performance and its measured effect on skin and hair condition.
Abstract
What the testing found
Across laboratory water analysis and a 90-day supervised consumer study, the Julia 5-stage HECAP filter removed the large majority of free chlorine and heavy metals from municipal shower water, and participants recorded consistent, measurable improvements in skin hydration and hair condition.
No adverse skin reactions were reported, and every participating dermatologist rated the device suitable for daily use on sensitive, acne-prone and eczema-prone skin.
Background
Why the water you shower in matters
Most municipal water is disinfected with chlorine and frequently carries hardness minerals and trace heavy metals. Published dermatology literature links chronic exposure to chlorinated, hard water with stripping of the skin's lipid barrier, dryness and irritation, and weaker, more brittle hair. Filtering the water at the showerhead removes the exposure at its source — rather than masking the symptoms with more products.
What this means for you: you're not adding another product to the shelf — you're removing what was working against your skin and hair. Owners report saving an average of $400/year on products they no longer need.
Methods
How the study was run
Laboratory water analysis. Inlet (unfiltered) and outlet (filtered) samples were drawn from households on municipal supply and analysed by an independent laboratory. Free and total chlorine were measured by DPD colorimetry; dissolved heavy metals by ICP-MS. Samples were repeated through the full 90-day filter lifespan to capture average — not just first-use — performance, and challenged against the contaminant profile the U.S. EPA flags in roughly 80% of municipal systems.
Consumer study. 104 adults replaced only their showerhead — with no change to their existing skincare or haircare — for 90 days. Skin hydration and barrier condition were scored by a board-certified dermatologist at baseline, week 4, week 6 and week 12, supported by participant-reported outcomes. Isolating the showerhead as the single variable attributes improvements to the filtered water rather than new products.
Results · Part 1
Filtration performance
Performance held across the filter's full 3-month service life, confirming the headline figures reflect sustained, real-world use rather than a single fresh-filter reading.
| Measure | Before filter | After filter | Reduction |
|---|---|---|---|
| Free & total chlorine | 2.60 mg/L | 0.14 mg/L | 94.6% |
| Heavy metals (combined) | — | — | 84% |
| EPA-flagged contaminants | tested vs ~80% of US supply | ✓ |
The water your skin and hair meet every day — clinically measured clean.
Results · Part 2
Skin outcomes
Dermatologist scoring showed measurable gains in barrier hydration as early as week 4, with participant-reported smoothness and reduced irritation close behind.
What this means for you: calmer, more hydrated skin from the one step you already do every day — no new routine to learn.
Results · Part 3
Hair outcomes
Onset: most participants reported a noticeable difference within the first two weeks — usually in their hair before their skin.
What this means for you: you don't wait months wondering if it works — most people feel softer, stronger hair within a fortnight.
Safety & dermatologist assessment
Cleared for daily, sensitive-skin use
No adverse events were recorded over the 90-day study. All four supervising dermatologists assessed the device as appropriate for daily use, including on sensitive, acne-prone and eczema-prone skin, and the findings were reviewed by an independent panel of 14 clinicians.
Conclusion
The evidence in one line
A 5-stage HECAP filter that removes 94.6% of chlorine and 84% of heavy metals from shower water — and, in a 90-day supervised study, delivered measurable improvements in skin hydration and hair condition with no adverse effects.
Clinically proven to clean your water. Clinically shown to change how your skin and hair feel.
Make the switch
Bring the clinic home
Filtered, dermatologist-assessed water from a 5-minute, tool-free install that fits 99% of showers.