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RATIONALE #5 The Serum

Sale price$194.00


#5 The Serum


The Clarity Collection 

Clarity. Balance. Radiance.


The Story

A potent revival of absolute clarity.

This sophisticated skin-refining serum recalibrates skin’s pH balance for a more even, smoother appearance.



The Promise

  • Skin tone and texture are refined, and clarity is restored
  • Recalibrates skin pH to a youthful acidic level
  • Clarifies skin to promote a more even appearance
  • Hydration levels are augmented to visibly smooth fine lines
  • Skin looks and feels softer and more radiant


The Ritual

Smooth gently over face, neck, décolletage and backs of hands each evening. 


Follow with your RATIONALE Essential Six formulations for night. 


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.


RATIONALE  #5 The Serum
RATIONALE #5 The Serum Sale price$194.00