C-Tetra® Advanced — Reddit Reviews
by Medik8
Updated October 3, 2026
20% vitamin C derivative serum for brighter skin; surprisingly gentle and moisturizing.
What the community says
A 20% vitamin C derivative serum with acetyl glucosamine, squalane, and hyaluronic acid in a thin cream-gel. People with sensitive skin and vitamin C haters like it; the catch is citrus oil and fragrance allergens.
What this means for you
Backed by 11 threads from r/SkincareAddiction, r/40plusskincare and 3 more.
Read the threads ↓What people love
- 20% vitamin C derivative for brightening
- Moisturizing thin cream-gel texture
- Usually kinder than L-ascorbic acid
Watch out for
- Contains grapefruit peel oil plus citral, linalool, and limonene
- Not an irritation-free bet for every sensitive-skin user
- Brightening is there, but anti-ageing payoff feels slower
Product details
Skin Type
Key Ingredients
Skin type data limited
Where to buy
What the science says
Hyperpigmentation
Some evidence
Vitamin C: 7 studies tested it on its own. See all 24 studies
What the studies found
- Most studies found vitamin C helped fade dark spots or patches
- In melasma studies, vitamin C on the skin often made patches look lighter over time
- Used with other treatments, vitamin C sometimes faded melasma more than the other treatment alone
- For sun spots, vitamin C showed some fading, but one study had mixed results
- It worked about as well as glycolic acid for fading melasma patches in one large review
Research context, not treatment advice. Studies are about the ingredient, not necessarily this exact product.
Real Reddit threads — 18 mentions across 11 threads
Medik8 C-Tetra® Advanced on Reddit, in one place — 11 threads from r/SkincareAddiction, r/40plusskincare and 3 more, summarized.
“Medik8 advanced tetra c has been incredible for my skin (no ascorbic acid)”
Positive
“I have super sensitive skin and it does not tolerate any formula that has Ascorbic Acid in it”
Positive
“So I'm forced to get derivative-based formulas.”
Positive
“I use their C-Tetra Advanced for Vitamin C”
Positive
“I've loved everything I've tried from Medik-8.”
Positive
“I use their C-Tetra Advanced for Vitamin C and their Liquid Peptides Advanced MP for my peptide serum.”
Positive
“Medik8's C-Tetra Advanced, Remedy”
Mentioned
“C-Tetra Advanced”
Mentioned
“Medik8's”
Mentioned
“my favourite products that really make a difference for me: Medik8 vit c”
Positive
“I feel a major difference for things like skin texture, dullness and acne marks.”
Positive
“Signs of ageing take longer though.”
Positive
“Medik8 C-Tetra Advanced”
Positive
“The Medik8 vitamin C is moisturising, it has a thin cream formula.”
Positive
“you can't go wrong with my prior Vitamin C, C-Tetra Advanced MP from Medik8, which was a pleasure to use!”
Positive
“Vitamin C: Medik8 c-tetra advanced”
Positive
“I use these three products regularly and my skin doesn’t get irritated.”
Positive
“Looking for niacinamide free replacements for: - a vitamin c”
Positive
