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GLOW

Medik8: the honest verdict.

The British clinical skincare brand built on the CSA philosophy, Vitamin C in the morning, Sunscreen always, Vitamin A at night. Tested across C-Tetra, Crystal Retinal, and Hydr8 B5.

9.0/10
Glow score
Position
Premium · Clinical skincare
Founded
United Kingdom · 2009
Available at
Adore Beauty + clinics
Reviewed by
GLOW Editorial Team · Editorial Team
Independent editorial team · glow.com.au/authors/
Updated
April 2026
The verdict · Skincare · Clinical actives

GLOW read.

Medik8's CSA philosophy is the most evidence-based routine framework on the consumer skincare market. The brand argues, correctly, that 80% of skincare results come from three categories used consistently: vitamin C, SPF, and vitamin A. Their products are built to deliver each.

Crystal Retinal is the standout. Encapsulated retinal (not retinol, one step closer to retinoic acid) at concentrations from 1 to 24, allowing clinical-grade actives without the prescription pathway. C-Tetra is a stable tetrahexyldecyl ascorbate vitamin C suitable for sensitive skin that can't tolerate L-ascorbic acid. Hydr8 B5 is one of the better hyaluronic acid serums on the shelf.

Medik8 is the brand to recommend when someone asks 'what should I actually use'. The CSA framework removes the decision fatigue that paralyses most skincare buyers. Pricing is clinical-tier ($85-150 per piece) but lower than SkinCeuticals.

What works

  • Crystal Retinal, encapsulated retinal at clinical concentrations without prescription
  • C-Tetra, stable vitamin C for sensitive skin that can't tolerate L-ascorbic acid
  • CSA framework gives consumers a clear routine logic, rare in the category
  • Pricing is premium but lower than SkinCeuticals for comparable actives
  • Distribution through dermatology clinics gives in-person consultation access

What doesn't

  • Brand recognition outside of skincare obsessives is low in Australia
  • Crystal Retinal scaling system (1, 3, 6, 10, 24) confuses first-time buyers
  • No SPF in the range, you'd buy La Roche-Posay or Ultra Violette to complete the CSA
GLOW Formulation Index · v1.0

What's actually in it.

A/ A–D
Actives
C-Tetra: 14% tetrahexyldecyl ascorbate (stable, non-irritating vitamin C ester) + vitamin E + squalane. Crystal Retinal: encapsulated retinaldehyde at 1-24mg/g concentrations.
Preservation
Phenoxyethanol + ethylhexylglycerin. Within EU/TGA safe limits.
Allergens
Genuinely fragrance-free across the clinical range.
Editorial concerns
None at use concentration. Formulation work is editorial-preferred. CSA framework is evidence-based.

Index grade is editorial, not paid. The grade reflects what's in the product against Glow's v1.0 watch list, it sits beside GLOW score, not instead of it. Medik8 earns a Grade A on formulation and on framework. The CSA philosophy (Vitamin C, Sunscreen, vitamin A) is the most evidence-based consumer skincare routine on the Australian market. If a friend asks 'what should I actually use', this is the answer.