strengthen your skin barrier

How Filaggrin, Eczema & L-Histidine Connect

Eczema is strongly linked to a weakened skin barrier, the skin’s first line of defense against moisture loss, irritants, allergens, and microbes. A key protein called filaggrin plays a central role in building and maintaining this barrier.

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FILAGGRIN SUPPORT

Eczema Relief Skin Barrier Protocol (3-12 months)

Eczema relief for the most sensitive skin, with L-Histidine to rebuild the skin barrier.
$71 $67.50
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Eczema Relief Skin Barrier Protocol (1-3 years)

Designed to reinforce the skin barrier and provide relief to itchy, compromised skin.
$96 $91
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Codex Labs skincare products including gummies, a bar of soap, and lotion on a white background

Eczema Relief Skin Barrier Protocol (4-12 years)

All the eczema relieving power of our L-Histidine powder supplements, now in gummy form.
$96 $91
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Eczema Relief Skin Barrier Protocol (13-17 years)

Eczema relief for teenagers - rebuild the skin barrier's filaggrin with L-Histidine.
$94 $89
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Skin Barrier Eczema Relief Protocol (18+)

Eczema relief for adults - rebuild the skin barrier's filaggrin with L-Histidine.
$142 $135
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What is filaggrin?

The filaggrin protein is what keeps your skin barrier intact. Low filaggrin means a leaky barrier, and a leaky barrier means dryness, irritation, and eczema. Supporting it both topically and internally is how you get real results.

Eczema isn’t a skin flaw. It’s a barrier problem.

In healthy skin…


Filaggrin helps pack skin cells tightly together, forming a strong, even outer barrier.

Breaks down into Natural Moisturizing Factors (NMFs) that retain water.

Protects against irritants, allergens, and microbes – keeping them out and moisture in.

In distressed skin…


Filaggrin levels are reduced: skin barrier weakens and less NMFs are produced to hold moisture.

Skin cells do not bind together as effectively, creating gaps in the barrier that allow moisture to escape and irritants to enter.

The skin struggles to retain hydration, leading to dryness and sensitivity

Low filaggrin triggers a vicious cycle.

A weakened barrier lets in irritants, which causes inflammation, which depletes filaggrin further, and around it goes.

HOW LOWERFILAGGRIN LEVELS
TRIGGER ECZEMA 
FLARES

Step 1
Leakier barrier

”Brick wall” weakens; dryness rises

Step 2
Higher skin pH

Infection and colonization risk grows

Step 3
Inflammation & Itch

Scratching damages the barrier further

Step 4
Lower filaggrin

Inflammation signals suppress production

What is the role of L-Histidine?

Your body needs L-Histidine to produce filaggrin. It's a simple equation: more L-Histidine means more raw material to rebuild the barrier.

95%

improvement in eczema severity, dryness, itch & scaling

When L-Histidine supplementation was combined with the Codex Labs Eczema Relief Lotion, 100% of subjects saw an average eczema severity score decrease of 95% and an improvement across eczema severity, dryness, itch, scaling, and barrier function — in about 8 weeks.

What the research shows about L-Histidine

95% improvement in 8 weeks.

Eczema severity, dryness, itch, and scaling all measurably improved when L-histidine and the right topicals worked together.

It feeds the skin barrier.

Your body uses L-Histidine to produce filaggrin and keep skin hydrated.

It reduces symptoms.

Less dryness, itch, and scaling — shown in clinical studies.

It’s better with topicals.

Paired with our Eczema Relief Lotion, 100% of infants and children improved with an average improvement of 95% in 8 weeks.

More filaggrin means less risk of, or less severe, eczema.

The topical routine: Boosting filaggrin from the outside

CODEX LABS UNSCENTED SOAP CODEX LABS UNSCENTED SOAP

Cleanser • Daily

A wash that protects the microbiome instead of stripping it

Our Unscented Soap gently cleanses without stripping the lipids and natural moisturizing factors filaggrin produces. Unlike harsh, fragranced cleansers that raise skin pH and disrupt filaggrin processing, it helps preserve the skin's natural barrier.

Fragrance-free & non-stripping
Cleans without dissolving the ceramide “mortar” or the filaggrin breakdown products that hold water.

Respects the acid mantle
A pH-conscious formula keeps the slightly acidic surface filaggrin needs to be processed correctly.

NOURISHING FACIAL OIL & GENTLE  CLEANSING OIL NOURISHING FACIAL OIL & GENTLE  CLEANSING OIL

Topical • Daily

A lotion that helps rebuild the barrier

Our Eczema Relief Lotion is formulated with barrier lipids and botanical actives to support the skin's own filaggrin cycle — not mask symptoms.

Reactivates filaggrin production

Helps restore filaggrin gene activity when inflammation suppresses expression, supporting healthy skin barrier function.

Calms the inflammation that suppresses it

Soothing botanicals quiet the Th2 signals that switch filaggrin genes down, breaking the vicious cycle.

Seals in moisture & restores pH

Ceramide-rich mortar locks water in and re-acidifies the surface, the conditions filaggrin needs to work.

The supplement: Boosting filaggrin from the inside

Skin Barrier Support Supplements Skin Barrier Support Supplements

Supplement • Daily

Rebuild the skin barrier from within

Our Skin Barrier Support Supplements pair the amino acid behind filaggrin with antioxidants that protect it — feeding the barrier at its source.

Delivers age-appropriate dose of L-Histidine
The amino-acid building block the body uses to make filaggrin and its natural moisturizing factors.

Antioxidant support
Antioxidants such as vitamins C & E and M3 (Maqui, Matico, and Murtilla) help reduce oxidative stress and inflammation that can impair filaggrin expression and skin barrier function.

Clinically studied results
A 34% reduction in SCORAD eczema-severity score reported after 30 days of daily use with the supplement alone.

Protect and seal filaggrin from the surface, rebuild it from within.

Barrier support works best from every direction: inside and out.

STEP 1

CLEANSE GENTLY

Fragrance-free & pH-balanced soap. Lukewarm water. Codex Labs’ Unscented Soap doesn’t strip skin hydration, oils or the skin microbiome.

STEP 2

SUPPORT TOPICALLY

Apply a nourishing oil that stimulates filaggrin production and seals in moisture, twice daily.

STEP 3

FEED IT FROM WITHIN

Daily L-Histidine at the studied dose, alongside any prescribed treatments.

BEST SELLERS

Clinically-Proven Eczema Relief Protocols for Every Age

Infants, 3m - 12m

SKIN BARRIER PROTOCOL

Infants, 3m - 12m

Eczema relief for the most sensitive skin, with L-Histidine to rebuild the skin barrier.
Toddlers 1y -3y

SKIN BARRIER PROTOCOL

Toddlers 1y -3y

Eczema relief for the the most sensitive skin, with L-Histidine to rebuild the skin barrier.
Kids, 3y -12y

SKIN BARRIER PROTOCOL

Kids, 3y -12y

All the eczema relieving power of our L-Histidine powder supplements, now in gummy form.
Teens 13y - 18y

SKIN BARRIER PROTOCOL

Teens 13y - 18y

Eczema relief for teenagers - rebuild the skin barrier's filaggrin with L-Histidine.
Adults

SKIN BARRIER PROTOCOL

Adults

Eczema relief for adults - rebuild the skin barrier’s filaggrin with L-Histidine

Feed your filaggrin.
Inside and out.

The Eczema Relief Skin Barrier Protocol pairs our pH-balanced Unscented Soap with a lotion that stimulates more filaggrin production and L-Histidine supplementation — a complete regimen built around the science of skin barrier repair.

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Four things to remember:

  • Eczema is structural. A weakened skin barrier — leading to inflammation that further weakens this barrier.

  • Filaggrin builds that barrier. It builds stronger skin cells, locks in moisture, and keeps irritants out.

  • L-histidine feeds filaggrin. It's the key building block your body needs to rebuild the skin barrier.

  • Genetics can work against you. Some people are wired to produce less filaggrin from the start.