#5 The Serum
#5 The Serum
#5 The Serum
#5 The Serum
Side arrow
Side arrow
Step 5: Clarity
?
This collection delivers a proprietary a suite of Hydroxy Acids and Peptides to recalibrate the skin’s pH.

#5 The Serum

Skin-refining serum for resilient skin.

1.0 fl.oz

$167.00
This advanced serum recalibrates skin's pH balance with a Complex of Hydroxy Acids, evening out skin tone and texture while amplifying radiance.

Use in the PM

Benefits
Plus
Minus
Restores clarity
Enhances radiance
Evens tone
Targets
Plus
Minus
Blemishes and congestion
Hyperpigmentation
Fine lines and wrinkles
Ingredients
Plus
Minus
Aqua (Water), Vaccinium Myrtillus Fruit Extract, Glycerin, Pentylene Glycol, Dimethyl Isosorbide, Lactic Acid, Saccharum Officinarum (Sugar Cane) Extract, Ethoxydiglycol, Citrus Aurantium Dulcis (Orange) Fruit Extract, Citrus Limon (Lemon) Fruit Extract, Ethylhexylglycerin, Lauryl Lactate, Salicylic Acid, Sodium Levulinate, Acer Saccharum (Sugar Maple) Extract, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Diutan Gum, Isohexadecane, Carbomer, Melaleuca Alternifolia (Tea Tree) Leaf, Sodium Anisate, Mentha Australis Leaf Extract, Santalum Spicatum (Sandalwood) Seed Oil, Citrus Aurantium Dulcis (Orange) Oil, Polysorbate 60, Butylene Glycol, Citrus Aurantium Bergamia (Bergamot) Fruit Oil, Citrus Grandis (Grapefruit) Peel Oil, Citrus Limon (Lemon) Peel Oil, Litsea Cubeba Fruit Oil, Citrus Aurantium Bergamia (Bergamot) Leaf Oil, Juniperus Mexicana Oil, Pelargonium Graveolens Oil, Lauryl Alcohol, Citrus Aurantium Amara (Bitter Orange) Flower Oil, Eugenia Caryophyllus (Clove) Leaf Oil, Citrus Australasica Fruit Extract, Sorbitan Isostearate, Magnesium Aspartate, Zinc Gluconate, Sodium Benzoate, Citric Acid, Potassium Sorbate, Copper Gluconate, Glycine, Serine, Glutamic Acid, Aspartic Acid, Leucine, Alanine, Lysine, Arginine, Tyrosine, Phenylalanine, Proline, Threonine, Valine, Isoleucine, Histidine, Limonene, Citral, Linalool

Complimentary express delivery on all orders.

Book a Consultation

Connect with an Online Skin Therapist.

 Take the Skin Questionnaire

Discover your personalised skincare Ritual.
Aqua (Water), Vaccinium Myrtillus Fruit Extract, Glycerin, Pentylene Glycol, Dimethyl Isosorbide, Lactic Acid, Saccharum Officinarum (Sugar Cane) Extract, Ethoxydiglycol, Citrus Aurantium Dulcis (Orange) Fruit Extract, Citrus Limon (Lemon) Fruit Extract, Ethylhexylglycerin, Lauryl Lactate, Salicylic Acid, Sodium Levulinate, Acer Saccharum (Sugar Maple) Extract, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Diutan Gum, Isohexadecane, Carbomer, Melaleuca Alternifolia (Tea Tree) Leaf, Sodium Anisate, Mentha Australis Leaf Extract, Santalum Spicatum (Sandalwood) Seed Oil, Citrus Aurantium Dulcis (Orange) Oil, Polysorbate 60, Butylene Glycol, Citrus Aurantium Bergamia (Bergamot) Fruit Oil, Citrus Grandis (Grapefruit) Peel Oil, Citrus Limon (Lemon) Peel Oil, Litsea Cubeba Fruit Oil, Citrus Aurantium Bergamia (Bergamot) Leaf Oil, Juniperus Mexicana Oil, Pelargonium Graveolens Oil, Lauryl Alcohol, Citrus Aurantium Amara (Bitter Orange) Flower Oil, Eugenia Caryophyllus (Clove) Leaf Oil, Citrus Australasica Fruit Extract, Sorbitan Isostearate, Magnesium Aspartate, Zinc Gluconate, Sodium Benzoate, Citric Acid, Potassium Sorbate, Copper Gluconate, Glycine, Serine, Glutamic Acid, Aspartic Acid, Leucine, Alanine, Lysine, Arginine, Tyrosine, Phenylalanine, Proline, Threonine, Valine, Isoleucine, Histidine, Limonene, Citral, Linalool

The Results

81%

noticed a boost in radiance and brightness.

91%

saw an improvement in even skin tone.

75%

experienced increased firmness.

*Based on a 28-day trial with 21 participants.

The Essential Six System

Each of our Essential Six Collections uniquely supports your skin health. Include at least one Formulation from each Collection in your Ritual.

AM
PM
1
Step 1: Resilience
This Collection delivers a proprietary Complex of B-Group Vitamins which support immunity and barrier function.
Shop Now
2
Step 2: Vitality
This Collection delivers a proprietary Complex of Antioxidants which defends against oxidative stress.
Shop Now
3
Step 3: Brilliance
This Collection delivers a proprietary Complex of Zinc Fusion Technology, Iron Oxides, and Melanin to offer superlative protection.
Shop Now
4
Step 4: Integrity
This Collection delivers a proprietary Complex of Ceramides and Lipids, which restore and nurture the skin’s barrier function.
Shop Now
Step 5: Clarity
This Collection delivers a proprietary suite of AHAs and Peptides to recalibrate the skin’s pH—for a refined, clear complexion.
Book Consultation Skin Questionnaire
6
Step 6: Renewal
This Collection delivers Vitamin A and Botanical Retinol Alternatives, plus Actives rich in DNA Repair Enzymes, to support cellular turnover.
Shop Now

The Ritual

Shake gently before use.

Dispense 2–3 drops into palm.

Gently smooth over face, neck, décolletage and backs of hands, avoiding the delicate eye area.

Inside the Formulation

Every RATIONALE Formulation is crafted with the highest quality of ingredients, formulated into three key Complexes.

The Primary Complex
Plus
Minus

A proprietary Complex of Hydroxy Acids refines skin's clarity.

What is a Primary Complex? 

Key ingredients that predominantly influence a Formulation.

The Secondary Complex
Plus
Minus

A powerful, unique profile of Botanical Extracts promotes a refined texture and tone.

What is the Secondary Complex?

Consists of supplementary ingredients that complement the Primary Complex.

The Delivery System
Plus
Minus

Water-Based

What is the Delivery System?

Carries active ingredients into the skin.

The Research

The pH of the skin’s outermost layer, the Stratum Corneum, is vital to complexion health, vitality and beauty.

The ideal state of the Stratum Corneum is acidic, as these conditions maintain the upregulation of enzymes critical to the synthesis of collagen and elastin (skin connective tissues that provide skin structure and firmness), as well as helping to prevent collagen breakdown, sensitivity, breakouts and infection.

Throughout life, skin becomes more alkaline as a result of intrinsic ageing and environmental damage. This leads to an upregulation of enzymes that break down skin connective tissues, leading to premature ageing, wrinkles and sagging.

Recalibrating and maintaining the acidic pH of skin is possible via a nightly regime of topically applied hydroxy acids which help to reverse the effects of facial ageing and environmental damage.

In Synergy With

#6 The Night Crème

#6 The Night Crème

Benefits

Uplifts and firms, Visibly hydrates , Reanimates luminosity ,

$198.00 | Add to Cart
Loading indicator
Tick Added to Cart
#4 The Cleanser

#4 The Cleanser

Benefits

Gently cleanses, Nourishes, Amplifies suppleness,

Shop Now
#1 The Serum

#1 The Serum

Benefits

Hydrates, Nourishes, Enhances radiance,

Shop Now
#3 The Tinted Serum Broad Spectrum SPF 50+

#3 The Tinted Serum Broad Spectrum SPF 50+

Benefits

Evens tone, Illuminates, SPF50+ protection,

$176.00 | Add to Cart
Loading indicator
Tick Added to Cart
Side arrow
Side arrow
Skin Questionnaire Book a Consultation