PSA SKIN Goals Multi Acids & Probiotics Perfecting Night Serum Versus Isntree Chestnut AHA 8% Clear Essence
This smoothing serum is formulated around Glycolic Acid and Gluconolactone to refine skin texture and brighten dull-looking skin.
This smoothing essence is formulated around Glycolic Acid and Lactic Acid to refine skin texture and brighten dull-looking skin.
What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningGlycerin
Humectant
Glycolic Acid
Buffering
Gluconolactone
Skin Conditioning
Propanediol
Solvent
Calophyllum Inophyllum Seed Oil
Antimicrobial
Sodium Hydroxide
BufferingTocopheryl Acetate
Antioxidant
Pyruvic Acid
MaskingLactobacillus Ferment
Skin Conditioning
Bisabolol
Antioxidant
Leuconostoc/Radish Root Ferment Filtrate
Antimicrobial
Rosa Canina Seed Oil
Emollient
Lactic Acid
Buffering
Salicylic Acid
Masking
Niacinamide
Smoothing
Sodium PCA
Humectant
Glycyrrhiza Glabra Root Extract
Bleaching
Butyrospermum Parkii Butter
Skin Conditioning
Camellia Sinensis Leaf Extract
Antimicrobial
Centella Asiatica Leaf Extract
Skin Conditioning
Hyaluronic Acid
Humectant
Sodium Hyaluronate Crosspolymer-3
HumectantPentapeptide-59
Skin Conditioning
Tetrahydrodiferuloylmethane
Antioxidant
Tetrahydrodemethoxydiferuloylmethane
Antioxidant
Tetrahydrobisdemethoxydiferuloylmethane
Antioxidant
Hydroxyethylcellulose
Emulsion StabilisingSclerotium Gum
Emulsion StabilisingMaltodextrin
Absorbent
Sodium Gluconate
Skin ConditioningHydrogenated Lecithin
Emulsifying
Dimethyl Sulfone
SolventEthylhexylglycerin
Skin ConditioningPotassium Sorbate
Preservative
Phenethyl Alcohol
MaskingPhenoxyethanol
Preservative
Water, Glycerin, Glycolic Acid, Gluconolactone, Propanediol, Calophyllum Inophyllum Seed Oil, Sodium Hydroxide, Tocopheryl Acetate, Pyruvic Acid, Lactobacillus Ferment, Bisabolol, Leuconostoc/Radish Root Ferment Filtrate, Rosa Canina Seed Oil, Lactic Acid, Salicylic Acid, Niacinamide, Sodium PCA, Glycyrrhiza Glabra Root Extract, Butyrospermum Parkii Butter, Camellia Sinensis Leaf Extract, Centella Asiatica Leaf Extract, Hyaluronic Acid, Sodium Hyaluronate Crosspolymer-3, Pentapeptide-59, Tetrahydrodiferuloylmethane, Tetrahydrodemethoxydiferuloylmethane, Tetrahydrobisdemethoxydiferuloylmethane, Hydroxyethylcellulose, Sclerotium Gum, Maltodextrin, Sodium Gluconate, Hydrogenated Lecithin, Dimethyl Sulfone, Ethylhexylglycerin, Potassium Sorbate, Phenethyl Alcohol, Phenoxyethanol
Water
Skin ConditioningGlycolic Acid
Buffering
Lactic Acid
Buffering
Butylene Glycol
Humectant
Glycerin
Humectant
Potassium Hydroxide
Buffering1,2-Hexanediol
Skin Conditioning
Castanea Crenata Shell Extract
Skin ConditioningPanthenol
Skin Conditioning
Sodium Hyaluronate
Humectant
Centella Asiatica Extract
Cleansing
Asiaticoside
Antioxidant
Asiatic Acid
Skin Conditioning
Madecassic Acid
Skin Conditioning
Madecassoside
Antioxidant
Portulaca Oleracea Extract
Skin Conditioning
Allantoin
Skin Conditioning
Paeonia Suffruticosa Root Extract
Skin ProtectingCaprylic/Capric Triglyceride
Masking
Hydrogenated Phosphatidylcholine
Emulsifying
Sucrose Stearate
EmollientCetearyl Alcohol
Emollient
Glyceryl Caprylate
EmollientHydroxyethylcellulose
Emulsion StabilisingEthylhexylglycerin
Skin ConditioningWater, Glycolic Acid, Lactic Acid, Butylene Glycol, Glycerin, Potassium Hydroxide, 1,2-Hexanediol, Castanea Crenata Shell Extract, Panthenol, Sodium Hyaluronate, Centella Asiatica Extract, Asiaticoside, Asiatic Acid, Madecassic Acid, Madecassoside, Portulaca Oleracea Extract, Allantoin, Paeonia Suffruticosa Root Extract, Caprylic/Capric Triglyceride, Hydrogenated Phosphatidylcholine, Sucrose Stearate, Cetearyl Alcohol, Glyceryl Caprylate, Hydroxyethylcellulose, Ethylhexylglycerin
Reviews
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.
Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
Learn more about EthylhexylglycerinGlycerin (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.
Learn more about GlycerinGlycolic Acid is arguably the most famous alpha hydroxy acid (AHA) with tons of research backing its benefits.
It is found naturally in sugar cane but the form used in skincare is usually synthetic for purity and stability.
Glycolic acid removes the top layer of dead skin cells to allow newer and fresher ones to emerge.
AHAs work by breaking down the structural “glue” that holds old skin cells in place. When that buildup is gone, your skin can renew itself more efficiently.
Research also shows glycolic acid stimulates collagen production, helping to firm and thicken the skin over time. This is one of its biggest advantages over other AHAs.
Overall, glycolic acid helps with:
Fun fact: Glycolic acid boosts skin hydration by helping it produce molecules that increase hyaluronic acid naturally.
To work best, glycolic acid products should have a pH between 3-4 (that’s where exfoliation is most effective but still gentle on skin).
The pH and concentration of a product are key to its effectiveness:
It is normal to feel a slight stinging sensation when using glycolic acid. This usually fades as your skin adjusts.
Because glycolic acid has the smallest molecular size in the AHA family, it can penetrate deeper, which enhances its effectiveness but also makes it more likely to irritate sensitive skin.
If your skin is very sensitive or prone to rosacea, glycolic acid may be too strong; in that case, try milder options like lactic acid or a PHA instead.
Recent studies suggest glycolic acid might even help protect against UV damage. But don’t skip sunscreen! Freshly exfoliated skin is more sensitive to the sun.
Glycolic acid is a skincare superstar. It smooths, brightens, hydrates, and firms the skin. Unless you’re highly sensitive, it’s well worth adding to your routine.
Read more about some other popular AHA's here:
Learn more about Glycolic AcidHydroxyethylcellulose is used to improve the texture of products. It is created from a chemical reaction involving ethylene oxide and alkali-cellulose. Cellulose is a sugar found in plant cell walls and help give plants structure.
This ingredient helps stabilize products by preventing ingredients from separating. It can also help thicken the texture of a product.
This ingredient can also be found in pill medicines to help our bodies digest other ingredients.
Learn more about HydroxyethylcelluloseLactic Acid is another well-loved alpha hydroxy acid (AHA). It is gentler than glycolic acid but still highly effective.
Its main role is to exfoliate the surface of the skin by loosening the “glue” that holds dead skin cells together. Shedding those old cells leads to smoother, softer, and more even-toned skin.
Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.
Like glycolic acid, it can:
Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.
Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.
To get results, choose products with a pH between 3-4.
Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.
Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.
When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.
Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.
Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.
Read more about some other popular AHA's here:
Learn more about Lactic AcidWater. 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
