Educational guide
Summer Fridays Jet Lag Overnight Eye Serum Versus Medik8 Crystal Retinal Ceramide Eye
Summer Fridays Jet Lag Overnight Eye Serum Versus Medik8 Crystal Retinal Ceramide Eye This anti-aging eye moisturizer is formulated around Ceramide NP and Retinyl Linoleate to soften the look of wrinkles and hydrate skin. This anti-aging eye moisturizer is for
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Summer Fridays Jet Lag Overnight Eye Serum Versus Medik8 Crystal Retinal Ceramide Eye
This anti-aging eye moisturizer is formulated around Ceramide NP and Retinyl Linoleate to soften the look of wrinkles and hydrate skin.
This anti-aging eye moisturizer is formulated around Retinal and Ceramide NP to soften the look of wrinkles and strengthen the skin barrier.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Glycerin
Water
Squalane
Caprylic/Capric Triglyceride
Isodecyl Neopentanoate
Hydrogenated Polydecene
Pentylene Glycol
Rosa Canina Seed Oil
Propanediol
Sodium Acrylates Copolymer
Borago Officinalis Seed Oil
Oenothera Biennis Oil
Ceramide NP
Bisabolol
Avena Sativa Bran Extract
Glycyrrhetinic Acid
Centella Asiatica Extract
Phospholipids
Retinyl Linoleate
Retinol
Tocopheryl Acetate
Tocopherol
Glycine Soja Oil
Gluconolactone
Polyglyceryl-10 Stearate
1,2-Hexanediol
Lecithin
Maltodextrin
Potassium Sorbate
Caprylhydroxamic Acid
Trisodium Ethylenediamine Disuccinate
Levulinic Acid
Sodium Levulinate
Benzyl Alcohol
Sodium Benzoate
Glycerin, Water, Squalane, Caprylic/Capric Triglyceride, Isodecyl Neopentanoate, Hydrogenated Polydecene, Pentylene Glycol, Rosa Canina Seed Oil, Propanediol, Sodium Acrylates Copolymer, Borago Officinalis Seed Oil, Oenothera Biennis Oil, Ceramide NP, Bisabolol, Avena Sativa Bran Extract, Glycyrrhetinic Acid, Centella Asiatica Extract, Phospholipids, Retinyl Linoleate, Retinol, Tocopheryl Acetate, Tocopherol, Glycine Soja Oil, Gluconolactone, Polyglyceryl-10 Stearate, 1,2-Hexanediol, Lecithin, Maltodextrin, Potassium Sorbate, Caprylhydroxamic Acid, Trisodium Ethylenediamine Disuccinate, Levulinic Acid, Sodium Levulinate, Benzyl Alcohol, Sodium Benzoate
Butyrospermum Parkii Butter
Arachidyl Alcohol
Cetearyl Isononanoate
Isododecane
Ethylhexyl Palmitate
Behenyl Alcohol
Cetearyl Alcohol
Glyceryl Stearate
Microcrystalline Cellulose
PPG-12/Smdi Copolymer
Cyclodextrin
Phytosterols
Phenoxyethanol
Arachidyl Glucoside
Dimethicone
Linoleic Acid
Pandanus Conoideus Fruit Oil
Hydroxyacetophenone
Sodium Stearoyl Glutamate
Cellulose
Helianthus Annuus Seed Oil
Sodium Hyaluronate
Retinal
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate
Lonicera Japonica Flower Extract
Daucus Carota Sativa Seed Oil
Lonicera Caprifolium Flower Extract
Sodium Polyaspartate
Xanthan Gum
Disodium EDTA
Rubus Chamaemorus Seed Oil
Ethylhexylglycerin
BHT
Sodium Hydroxide
Trihydroxystearin
Water, Caprylic/Capric Triglyceride, Butyrospermum Parkii Butter, Propanediol, Arachidyl Alcohol, Cetearyl Isononanoate, Glycerin, Isododecane, Squalane, Ethylhexyl Palmitate, Behenyl Alcohol, Cetearyl Alcohol, Glyceryl Stearate, Microcrystalline Cellulose, PPG-12/Smdi Copolymer, Tocopheryl Acetate, Cyclodextrin, Phytosterols, Phenoxyethanol, Arachidyl Glucoside, Dimethicone, Sodium Acrylates Copolymer, Tocopherol, Linoleic Acid, Pandanus Conoideus Fruit Oil, Ceramide NP, Bisabolol, Hydroxyacetophenone, Sodium Stearoyl Glutamate, Cellulose, Helianthus Annuus Seed Oil, Lecithin, Sodium Hyaluronate, Retinal, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Lonicera Japonica Flower Extract, Daucus Carota Sativa Seed Oil, Lonicera Caprifolium Flower Extract, Sodium Polyaspartate, Xanthan Gum, Disodium EDTA, Rubus Chamaemorus Seed Oil, Ethylhexylglycerin, BHT, Pentylene Glycol, Sodium Hydroxide, Trihydroxystearin
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.
Bisabolol is a gentle skin conditioner, antioxidant, and soothing ingredient.
It's primary claim to fame is soothing and research shows topically applied bisabolol can quiet the chemical messengers that cause your skin to become inflamed, helping to sooth any irritation.
A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin.
In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum.
You'll likely see use concentrations quite low, usually 0.1-0.2%.
Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure skin.
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%.
Ceramide NP (formerly known as Ceramide 3) is one of the skin's naturally occurring lipids.
Since ceramides are the major lipid components of the skin, they are crucial for maintaining skin barrier and hydration. Ceramide NP most closely mirrors the dominant kind in human skin amongst ceramide subtypes.
This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.
A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.
Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.
Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.
Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.
Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Topically, glycerin does several things at once:
Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.
Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.
This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.
Just know very high concentrations (>40%) can feel tacky in low humidity.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Lecithin is a term for a group of substances found in the cell membranes of plants, animals, and humans. They are made up of phospholipids.
Thanks to its amphiphilic structure (water-loving head and oil-loving tail), it is a true multitasker:
It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.
Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:
Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.
On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.
Typical use levels in a formula run about 1-5%.
Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
This ingredient is a synthetic, salt form polymer built from acrylic acid, ethacrylic acid, or their simple esters. It works as a binder, film former, and viscosity increasing agent.
Typical concentrations start at around 0.5% but can go up to 25% for film-forming or binding.
The CIR Expert Panel assessed the safety of 126 acrylates copolymers and concluded they are safe in cosmetics at current use levels when formulated to be non-irritating. They also noted the levels present in finished cosmetic products are not considered a safety risk and Genotoxicity testing (Ames tests, chromosomal aberration assays) has come back negative across the board.
Though the raw building blocks (like acrylic acid) can be irritating on their own, cosmetic-grade versions go through purification to keep levels extremely low.
Sodium Acrylates Copolymer is a large molecule that doesn't penetrate skin barrier in any meaningful way.
Squalane is the hydrogenated and shelf-stable form of squalene (a lipid that naturally occurs in human sebum).
It is an emollient and skin conditioning agent that is able to integrate seamlessly into the skin's lipid barrier without clogging pores.
This is due to how structurally similar it is to what your skin already produces.
Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.
Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.
No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).
Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.
This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.
Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.
Read more about squalene with an "e".
Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.
The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.
Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.
A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.
The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.
Tocopherol is a fat-soluble antioxidant known as Vitamin E.
You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.
Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.
It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.
This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.
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.
In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.
Concentrations usually range from 0.1-1% in most leave-on products.
Tocopheryl 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.
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%.
Water. 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!