Medik8 C-Tetra Lipid Vitamin C Serum dupe

The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F

−61%per oz

Medik8 · $53The Ordinary · $20.50

Medik8 C-Tetra Lipid Vitamin C Serum against The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F
Fact	Medik8	The Ordinary
Type	Vitamin C serum	Vitamin C oil
Key ingredients	✓ Tetrahexyldecyl ascorbate, Jojoba oil, Vitamin E	✓ Tetrahexyldecyl ascorbate, Ethyl linoleate
Size	30 ml	30 ml
Per ounce	$52.25 / fl oz	$20.21 / fl oz
Sold by	Medik8	Amazon.com

The trade-off

Medik8 calls its serum 7% vitamin C and carries it in silicones with vitamin E and grapefruit peel oil, which brings citral, limonene and linalool, while The Ordinary's is 20% tetrahexyldecyl ascorbate in coconut alkanes with ethyl linoleate and squalane and no fragrance, so it sits oilier on the skin.

C-Tetra Lipid Vitamin C Serum costs about $53 for 30 ml ($52.25 / fl oz). The dupe below is The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F at $20.50, about 61% less per ounce. Each pair is compared on format, finish and key ingredients, including what the dupe doesn't do.

Water-free morning serum Medik8 calls 7% vitamin C: tetrahexyldecyl ascorbate, the oil-soluble form, in jojoba oil and silicones with vitamin E and grapefruit peel oil. Wear under sunscreen. 30 ml.

Amazon prices as of Oct 8, 2026, 6:00 PM ET, subject to change: the price on Amazon at checkout is the one that applies.

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The dupe, side by side

The original

Medik8

C-Tetra Lipid Vitamin C Serum

$53

$52.25 / fl oz

The dupe

The Ordinary

Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F

$20.50

$20.21 / fl oz

Cost per fl oz

Original$52.25 / fl oz

Dupe$20.21 / fl oz

$32.50 less at checkout than the original.

What matches

Same vitamin C ester in the same kind of water-free serum: tetrahexyldecyl ascorbate, the oil-soluble form that stings far less than ascorbic acid, with jojoba oil on both labels.

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Questions

What is the best dupe for Medik8 C-Tetra Lipid Vitamin C Serum?

The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F at about $20.50. Same vitamin C ester in the same kind of water-free serum: tetrahexyldecyl ascorbate, the oil-soluble form that stings far less than ascorbic acid, with jojoba oil on both labels.

How much cheaper is The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F than C-Tetra Lipid Vitamin C Serum?

C-Tetra Lipid Vitamin C Serum costs about $53 for 30 ml, or $52.25 / fl oz. The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F works out at $20.21 / fl oz, roughly 61% less per ounce.

Is Medik8 C-Tetra worth it?

C-Tetra Lipid Vitamin C Serum costs about $53 for 30 ml, about 2.6 times as much per ounce as The Ordinary Ascorbyl Tetraisopalmitate Solution 20% in Vitamin F. The trade-off with The Ordinary: Medik8 calls its serum 7% vitamin C and carries it in silicones with vitamin E and grapefruit peel oil, which brings citral, limonene and linalool, while The Ordinary's is 20% tetrahexyldecyl ascorbate in coconut alkanes with ethyl linoleate and squalane and no fragrance, so it sits oilier on the skin. If that doesn't matter to you, the original isn't worth the extra $33.