Medik8 Crystal Retinal Versus Klira Skinsize 04
This anti-aging serum is formulated around 3-O-Ethyl Ascorbic Acid and Tetrahexyldecyl Ascorbate to soften the look of wrinkles and refine skin texture.
What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningCaprylic/Capric Triglyceride
MaskingGlycerin
HumectantIsododecane
EmollientCetearyl Olivate
Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Emulsion StabilisingCetearyl Alcohol
EmollientPPG-12/Smdi Copolymer
EmollientSorbitan Olivate
EmulsifyingTocopheryl Acetate
AntioxidantCyclodextrin
AbsorbentSqualane
EmollientHydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Emulsion StabilisingHydroxyacetophenone
Antioxidant3-O-Ethyl Ascorbic Acid
Skin ConditioningHydroxypropyl Methylcellulose
Emulsion StabilisingSodium Hyaluronate
HumectantPhenoxyethanol
PreservativeTetrahexyldecyl Ascorbate
AntioxidantDaucus Carota Sativa Seed Oil
EmollientRetinal
Skin ConditioningRubus Chamaemorus Seed Oil
Skin ConditioningAlumina
AbrasiveIsostearic Acid
CleansingLecithin
EmollientPolyglyceryl-3 Polyricinoleate
EmulsifyingLonicera Japonica Flower Extract
Skin ConditioningLonicera Caprifolium Flower Extract
PerfumingPolyhydroxystearic Acid
EmulsifyingStearic Acid
CleansingSodium Polyaspartate
HumectantPentylene Glycol
Skin ConditioningCitric Acid
BufferingPolysorbate 60
EmulsifyingDisodium EDTA
Ethylhexylglycerin
Skin ConditioningBHT
AntioxidantSorbitan Isostearate
EmulsifyingVanilla Planifolia Fruit Extract
Skin ConditioningDipteryx Odorata Bean Extract
MaskingCoumarin
PerfumingCI 14700
Cosmetic ColorantCI 77891
Cosmetic ColorantWater, Caprylic/Capric Triglyceride, Glycerin, Isododecane, Cetearyl Olivate, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Cetearyl Alcohol, PPG-12/Smdi Copolymer, Sorbitan Olivate, Tocopheryl Acetate, Cyclodextrin, Squalane, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Hydroxyacetophenone, 3-O-Ethyl Ascorbic Acid, Hydroxypropyl Methylcellulose, Sodium Hyaluronate, Phenoxyethanol, Tetrahexyldecyl Ascorbate, Daucus Carota Sativa Seed Oil, Retinal, Rubus Chamaemorus Seed Oil, Alumina, Isostearic Acid, Lecithin, Polyglyceryl-3 Polyricinoleate, Lonicera Japonica Flower Extract, Lonicera Caprifolium Flower Extract, Polyhydroxystearic Acid, Stearic Acid, Sodium Polyaspartate, Pentylene Glycol, Citric Acid, Polysorbate 60, Disodium EDTA, Ethylhexylglycerin, BHT, Sorbitan Isostearate, Vanilla Planifolia Fruit Extract, Dipteryx Odorata Bean Extract, Coumarin, CI 14700, CI 77891
Reviews
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
In practice, that translates to a long shelf life and a consistently elegant skin feel.
While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.
Learn more about Caprylic/Capric TriglyceridePhenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.
On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.
Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.
Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.
Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.
Learn more about PhenoxyethanolTocopheryl Acetate is a stable, shelf-friendly form of vitamin E.
Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.
It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.
One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.
Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.
Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.
This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.
Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.
The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.
Most leave-on skincare keeps it at the lower end, often between 0.5-1%.
Learn more about Tocopheryl AcetateWater. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!
Learn more about Water