Ingredient
Decoder

Decodethe label.

Four ingredients everyone's talking about, explained in plain words with the studies behind them, plus a printable routine planner.

Ingredient cards

PDRN(polydeoxyribonucleotide)

On the label

polydeoxyribonucleotide, sodium DNA, PDRN.

What it is

DNA-derived fragments, often sourced from salmon or trout. Found in serums, creams, masks and, in clinics, injectables.

What research says

Reviews describe PDRN being studied for wound healing and skin rejuvenation. A 2025 review notes the terms PDRN and PN (polynucleotides) are used inconsistently and proposes a size-based definition. Several review authors work for companies in the field.

Sources

Marques C et al. Biomolecules 2025;15(1):148. PMID 39858543. https://pubmed.ncbi.nlm.nih.gov/39858543/ · Polydeoxyribonucleotide: A Promising Biological Platform to Accelerate Impaired Skin Wound Healing. Pharmaceuticals (Basel) 2021. PMID 34832885. https://pubmed.ncbi.nlm.nih.gov/34832885/

Hypochlorous acid(HOCl)

On the label

hypochlorous acid.

What it is

a mild form of chlorine-based acid; in skincare usually a water-like spray.

What research says

Lab and clinical studies have looked at its antimicrobial and anti-inflammatory properties; how it behaves on skin depends heavily on pH and formulation stability. (The 2018 review authors were paid consultants for a manufacturer.)

Sources

Del Rosso JQ, Bhatia N. J Clin Aesthet Dermatol 2018;11(11):36-39. PMID 30588272. https://pubmed.ncbi.nlm.nih.gov/30588272/ · Hypochlorous Acid: Clinical Insights and Experience in Dermatology... Biomedicines 2025. PMID 41462936. https://pubmed.ncbi.nlm.nih.gov/41462936/

Mandelic acid

On the label

mandelic acid.

What it is

an alpha-hydroxy acid (AHA) originally derived from bitter almonds; a larger molecule than glycolic acid.

What research says

A small 2018 study (24 people, 4 weeks, no control group) measured skin elasticity and firmness changes with a topical mandelic acid formula. A 2020 Cochrane review of topical acne treatments, including fruit acids (AHAs), rated much of the evidence as low certainty.

Note: AHAs can increase skin sensitivity to the sun; the FDA advises using sun protection when using AHA products. Source: FDA, Alpha Hydroxy Acids.

Sources

Jacobs SW, Culbertson EJ. Facial Plast Surg 2018;34(6):651-656. PMID 30513536. https://pubmed.ncbi.nlm.nih.gov/30513536/ · Cochrane Database Syst Rev 2020. PMID 32356369. https://pubmed.ncbi.nlm.nih.gov/32356369/

Panthenol(pro-vitamin B5)

On the label

panthenol, D-panthenol, dexpanthenol.

What it is

a precursor of pantothenic acid (vitamin B5); dexpanthenol is its active form. A long-standing moisturising ingredient.

What research says

A human study measured stratum corneum hydration and barrier function after topical dexpanthenol; a 2017 review summarises 70 years of topical use.

Sources

Gehring W, Gloor M. Arzneimittelforschung 2000. PMID 10965426. https://pubmed.ncbi.nlm.nih.gov/10965426/ · Proksch E et al. J Dermatolog Treat 2017;28(8):766-773. PMID 28503966. https://pubmed.ncbi.nlm.nih.gov/28503966/

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Four ingredients everyone's talking about, explained in plain words with the studies behind them, plus a printable routine planner.

  • Ingredient cards
  • Weekly AM/PM planner
  • Patch-test log + Notes for my dermatologist
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