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#5 The Serum
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Not recommended for your sensitivity
The StoryA potent revival of absolute clarity. This sophisticated skin-refining serum recalibrates skin’s pH balance for a more even, smoother appearance.
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Approved for Baumann Skin Types
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Approved for 13 of the 16 Baumann Skin Types. Dr. Baumann reviews every product against all 16 types before it goes on the site.
What it is and what it does
The Story
A potent revival of absolute clarity.
This sophisticated skin-refining serum recalibrates skin’s pH balance for a more even, smoother appearance.
As skin rejuvenation is optimised and irritation calmed, skin looks and feels immediately renewed, resurfaced and deeply luminous.
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.
Who it is for
Approved for 13 of the 16 Baumann Skin Types.
Key ingredients

Anti redness exfoliant that gets thru skin oil to remove blackheads. Calms acne and rosacea. Loved by oily skin types.

Exfoliating alpha hydroxy acid to renew and smooth skin

Glycerin (Glycerol) is the best natural moisturizing ingredient to hydrate skin quickly. May give products a sticky feel.
Full ingredient list
Product type and skin type data
| Brand | Rationale |
|---|---|
| Product type | Facial Treatment |
| Size | 1.0 oz. |
| Item number | RAT-CS |
| Approved Baumann Skin Types | ORPT, ORPW, ORNW, DRPT, DRPW, DRNW, DSPT, DSPW, DSNW, OSPT, OSPW, OSNW, DSNT |
| Recommended for these sensitivities | Acne |
Frequently bought together
Dr. Baumann pairs these together.
Reviews
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