HoliFrog Kosi Multi-Acid Mask

HoliFrog Kosi Multi-Acid Mask

Efficacy87/100IrritancyMedium

Works for

Exfoliation
Gluconolactone, Lactic acid + 2 more
Works well
What the product description says
“A concentrated multi-acid mask for weekly resurfacing.”
Source: Holifrog

This product can help exfoliate the skin. In other words, it helps break down the bonds between dead cells on the surface of the skin and speed up the skin turnover. Skin often appears softer and brighter after exfoliation, but overdoing it can result in disrupted skin barrier. The following ingredient is doing the exfoliating job in this product: gluconolactone, lactic acid, mandelic acid, salicylic acid.

GluconolactoneKey activeEffect: HighA polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicals~4.5–6.8%
Lactic acidKey activeEffect: HighAn exfoliating and moisturizing alpha-hydroxy acid (AHA). Typically causes less irritation than other AHAs, for example, glycolic acid. At high concentrations (about 15%), lactic acid can help reduce lines and wrinkles. Recent studies show that lactic acid can support the "good" bacteria living on skin's surface (healthy skin microbiome)~2.7–4%
Salicylic acidKey activeEffect: HighUsed for skin exfoliation. It has an anti-inflammatory and anti-bacterial effect, helps to unclog pores, prevent blemishes and speed up healing of the existing ones. Sometimes referred to as a BHA (beta-hydroxy acid)~0.45–1.05%
Mandelic acidKey activeEffect: HighHelps shed the upper layer of dead cells from the surface of the skin revealing smoother, brighter skin. It can help to reduce hyperpigmentation. It has anti-bacterial properties, and might help to reduce blemishes, as well as fine lines and wrinkles. It is considered to be gentler than glycolic acid~0.35–0.8%
Moisturizing
Gluconolactone, Lactic acid + 5 more
Works
What the product description says
“— Chlamydomonas Reinhardtii (AcquaSeal® Algae): helps renew and hydrate skin, rare at retail”
Source: Holifrog

This product can help improve hydration of the skin with the two types of ingredients.

The first type is called “humectants”:
these ingredients help attract water. When humectants are on the surface of the skin, they “pull in” the moisture from the outside environment, or from within deeper layers of the skin. The following ingredients in this product do the job: glycerin, lactic acid.

This product also contains ingredients called “occlusives”. They help reduce the speed with which our skin loses moisture to the outside environment. These ingredients also help soften the upper layer of the skin, so it feels less tight and nicer to the touch. The following ingredients in this product do the job: helianthus annuus seed oil, simmondsia chinensis seed oil.

GluconolactoneKey activeEffect: HighA polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicals~4.5–6.8%
Lactic acidKey active· HumectantEffect: HighAn exfoliating and moisturizing alpha-hydroxy acid (AHA). Typically causes less irritation than other AHAs, for example, glycolic acid. At high concentrations (about 15%), lactic acid can help reduce lines and wrinkles. Recent studies show that lactic acid can support the "good" bacteria living on skin's surface (healthy skin microbiome)~2.7–4%
GlycerinKey active· HumectantEffect: HighOne of the best moisturizing ingredients. Naturally present in skin. It attracts water to the upper layer of the skin working as a humectant~2.1–3.1%
Simmondsia chinensis seed oilKey active· Emollient, OcclusiveEffect: HighSoftens the upper layer of skin and helps restore the healthy skin barrier. Has shown to help calm down inflammation in skin. It is a stable oil, meaning that it retains its properties even when exposed to air.~1.5–2.2%
Helianthus annuus seed oilKey active· Emollient, OcclusiveEffect: HighA great emollient due to its high linoleic acid content. One of the most effective plant oils in helping skin hydration and repairing skin barrier function~0.35–0.8%
LysolecithinEffect: LowLecithin derivative. It helps oil and water mix together and can enhance penetration of other ingredients. It helps soften the upper layer of the skin~0.1–0.5%
Avena sativa kernel extractUnder-dosedAn effective moisturizing and skin barrier repair ingredient. Helps calm down inflammation and has some anti-oxidant properties~0.15–0.6%
Anti-aging
Side benefit the brand mentions · Gluconolactone, Lactic acid
Works well
What the product description says
“Penetrates below skin’s surface to repair damage on a cellular level, preventing the appearance of future damage and premature aging.”
Source: Holifrog

This product can help reduce and prevent fine lines and wrinkles, improve skin elasticity and firmness because it contains gluconolactone.

These ingredients in the product can also be helpful, even though there is less evidence for their effectiveness: lactic acid.

Keep in mind that it typically takes at least 6 weeks to notice any results because the changes that are needed to improve fine lines and elasticity happen in the deeper layers of the skin. No topical anti-aging product can “erase” wrinkles or fully reverse signs of aging.

GluconolactoneKey activeEffect: HighA polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicals~4.5–6.8%
Lactic acidKey activeEffect: MediumAn exfoliating and moisturizing alpha-hydroxy acid (AHA). Typically causes less irritation than other AHAs, for example, glycolic acid. At high concentrations (about 15%), lactic acid can help reduce lines and wrinkles. Recent studies show that lactic acid can support the "good" bacteria living on skin's surface (healthy skin microbiome)~2.7–4%
Evens skin tone
Side benefit the brand mentions · Gluconolactone, Lactic acid + 2 more
Works well
What the product description says
“Brightens skin overall, diminishing hyperpigmentation and dullness, while restoring vibrancy to skin tone.”
Source: Holifrog

This product can help reduce hypepigmentation and even out the skin tone because it contains the following effective ingredients: gluconolactone, lactic acid, mandelic acid, salicylic acid

Keep in mind that you would need to apply any topical skincare targetted at hypigmentation consistently for a couple of months to get a result. No topical skincare product can help get rid of hyperpigmentation (including post-acne marks and age spots) instantly.

GluconolactoneKey activeEffect: HighA polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicals~4.5–6.8%
Lactic acidKey activeEffect: HighAn exfoliating and moisturizing alpha-hydroxy acid (AHA). Typically causes less irritation than other AHAs, for example, glycolic acid. At high concentrations (about 15%), lactic acid can help reduce lines and wrinkles. Recent studies show that lactic acid can support the "good" bacteria living on skin's surface (healthy skin microbiome)~2.7–4%
Mandelic acidKey activeEffect: HighHelps shed the upper layer of dead cells from the surface of the skin revealing smoother, brighter skin. It can help to reduce hyperpigmentation. It has anti-bacterial properties, and might help to reduce blemishes, as well as fine lines and wrinkles. It is considered to be gentler than glycolic acid~0.35–0.8%
Salicylic acidEffect: LowUsed for skin exfoliation. It has an anti-inflammatory and anti-bacterial effect, helps to unclog pores, prevent blemishes and speed up healing of the existing ones. Sometimes referred to as a BHA (beta-hydroxy acid)~0.45–1.05%
Anti-blemish
Side benefit · Salicylic acid, Gluconolactone + 3 more
Works well

This product can help reduce breakouts and clogged pores because it contains the following ingredient: salicylic acid. This ingredient is used for treating acne and can have a noticeable effect.

The following ingredient (ingredients) in this product might be helpful, but there is no evidence to confirm that it actually works: gluconolactone, mandelic acid

Salicylic acidHeroEffect: HighUsed for skin exfoliation. It has an anti-inflammatory and anti-bacterial effect, helps to unclog pores, prevent blemishes and speed up healing of the existing ones. Sometimes referred to as a BHA (beta-hydroxy acid)~0.45–1.05%
GluconolactoneKey activeEffect: MediumA polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicals~4.5–6.8%
Mandelic acidKey activeEffect: MediumHelps shed the upper layer of dead cells from the surface of the skin revealing smoother, brighter skin. It can help to reduce hyperpigmentation. It has anti-bacterial properties, and might help to reduce blemishes, as well as fine lines and wrinkles. It is considered to be gentler than glycolic acid~0.35–0.8%
BentoniteEffect: LowHelps stabilize the product formulation~1.3–1.9%
Ginkgo biloba leaf extractEffect: LowA plant extract that might help neutralize free radicals and reduce inflammation in skin. It can be irritating~0.15–0.55%
Anti-oxidation
Side benefit · Gluconolactone, Ginkgo biloba leaf extract + 2 more
May help

This product contains antioxidants (ginkgo biloba leaf extract, gluconolactone) that might be able to help neutralize free radicals in skin to lessen the damage it gets from the UV light (sun). There is not enough evidence to confirm their effectiveness in skin though.

GluconolactoneKey activeEffect: MediumA polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicals~4.5–6.8%
Ginkgo biloba leaf extractKey activeEffect: MediumA plant extract that might help neutralize free radicals and reduce inflammation in skin. It can be irritating~0.15–0.55%
Melia azadirachta flower extractEffect: LowA plant extract that might be helpful to neutralize free radicals in skin~0.15–0.7%
Avena sativa kernel extractEffect: Low, below effective doseAn effective moisturizing and skin barrier repair ingredient. Helps calm down inflammation and has some anti-oxidant properties~0.15–0.6%

Can it cause trouble?

Irritancy
13 flagged ingredients
Medium risk
We flagged 13 ingredients with irritancy potential. Severity depends on your sensitivity threshold; the table lists the worst offenders first.
IngredientFunctionIrritationEst. amount
Salicylic acidUsed for skin exfoliation. It has an anti-inflammatory and anti-bacterial effect, helps to unclog pores, prevent blemishes and speed up healing of the existing ones. Sometimes referred to as a BHA (beta-hydroxy acid)High~0.45–1.05%est.
Mandelic acidHelps shed the upper layer of dead cells from the surface of the skin revealing smoother, brighter skin. It can help to reduce hyperpigmentation. It has anti-bacterial properties, and might help to reduce blemishes, as well as fine lines and wrinkles. It is considered to be gentler than glycolic acidHigh~0.35–0.8%est.
Curcuma longa root extractA plant extract that can contain an active compound curcumin, that may have some anti-inflammatory properties when applied to the skin, but solid research is lacking and the typical concentration used in skincare products is too low. Can be an irritantHigh~0.15–0.6%est.
Ginkgo biloba leaf extractA plant extract that might help neutralize free radicals and reduce inflammation in skin. It can be irritatingHigh~0.15–0.55%est.
PullulanCreates a thin drying film on the skin resulting in a short-term tightening effectHigh~0.05–0.25%est.
GluconolactoneA polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicalsMedium~4.5–6.8%est.
Lactic acidAn exfoliating and moisturizing alpha-hydroxy acid (AHA). Typically causes less irritation than other AHAs, for example, glycolic acid. At high concentrations (about 15%), lactic acid can help reduce lines and wrinkles. Recent studies show that lactic acid can support the "good" bacteria living on skin's surface (healthy skin microbiome)Medium~2.7–4%est.
Isoamyl laurateHelps stabilize emulsions and create a nice product textureMedium~1.7–2.5%est.
Simmondsia chinensis seed oilSoftens the upper layer of skin and helps restore the healthy skin barrier. Has shown to help calm down inflammation in skin. It is a stable oil, meaning that it retains its properties even when exposed to air.Medium~1.5–2.2%est.
Melia azadirachta flower extractA plant extract that might be helpful to neutralize free radicals in skinMedium~0.15–0.7%est.
Isoamyl cocoateHelps oil and water mix together and works as a cleansing agentMedium~0.15–0.5%est.
Potassium sorbateA preservativeMedium~0.05–0.3%est.
Leuconostoc/radish root ferment filtrateA preservative that comes from radishes fermented by a bacteria. New research suggests that the preservation properties in the ingredient come from an ammonium salt that is not present naturally in radish root but used in its cultivation. Is problematic because the exact amount of the preservative agents is difficult to determineMedium~0.05–0.15%est.
Comedogenic
Clean of flagged comedogenic ingredients
None flagged

User reviews

Would you recommend?
No community reviews yet.

Be the first — your take helps the next person decide.

Ingredients

Filter by role to see what each ingredient is doing.

Water~40–60%
Formula
Irritation risk
Low

Plain old water

More about Water
Gluconolactone~4.5–6.8%
Key activeIrritant · medium
Irritation risk
Medium
Works for
MoisturizingAnti-agingEvens skin toneExfoliationAnti-oxidationAnti-blemish

A polyhydroxy acid (PHA) that helps shed the dead cells from the skin surface revealing smoother skin. Is believed to be genter than AHAs. It helps attract water to the upper layer of the skin and can stimulate production of skin's own hyaluronic acid resulting in improved hydration levels. It has been shown to be helpful against acne and clogged pores if used consistently (e.g over a period of 12 weeks) in high enough concentration. It can help reduce fine lines and wrinkles and improve skin tone with long-term application. Can help neutralize free radicals

More about Gluconolactone
Prunus persica kernel oil~3.9–5.8%
Formula
Lactic acid~2.7–4%
Key activeIrritant · medium
Irritation risk
Medium
Works for
Evens skin toneMoisturizingExfoliationAnti-aging

An exfoliating and moisturizing alpha-hydroxy acid (AHA). Typically causes less irritation than other AHAs, for example, glycolic acid. At high concentrations (about 15%), lactic acid can help reduce lines and wrinkles. Recent studies show that lactic acid can support the "good" bacteria living on skin's surface (healthy skin microbiome)

More about Lactic acid
Glycerin~2.1–3.1%
Key active
Irritation risk
Low
Works for
Moisturizing

One of the best moisturizing ingredients. Naturally present in skin. It attracts water to the upper layer of the skin working as a humectant

More about Glycerin
Isoamyl laurate~1.7–2.5%
Irritant · medium
Irritation risk
Medium

Helps stabilize emulsions and create a nice product texture

More about Isoamyl laurate
Simmondsia chinensis seed oil~1.5–2.2%
Key activeIrritant · medium
Irritation risk
Medium
Works for
Moisturizing

Softens the upper layer of skin and helps restore the healthy skin barrier. Has shown to help calm down inflammation in skin. It is a stable oil, meaning that it retains its properties even when exposed to air.

More about Simmondsia chinensis seed oil
Bentonite~1.3–1.9%
Formula
Irritation risk
Low
Works for
Anti-blemish

Helps stabilize the product formulation

More about Bentonite
Malic acid~1–1.5%
Formula
Irritation risk
Low

Helps adjust the product pH

More about Malic acid
Cetearyl olivate~0.8–1.25%
Formula
Irritation risk
Low
Works for
Cleansing

Helps oil and water mix together

More about Cetearyl olivate
Salicylic acid~0.45–1.05%
Hero · Anti-blemishIrritant · high
Irritation risk
High
Works for
Anti-blemishExfoliationAnti-inflammatoryAntibacterialEvens skin tone

Used for skin exfoliation. It has an anti-inflammatory and anti-bacterial effect, helps to unclog pores, prevent blemishes and speed up healing of the existing ones. Sometimes referred to as a BHA (beta-hydroxy acid)

More about Salicylic acid
Sorbitan olivate~0.45–1%
Formula
Irritation risk
Low
Works for
Cleansing

Helps oil and water mix together

More about Sorbitan olivate
Undaria pinnatifida cell culture extract~0.35–0.85%
Formula
Mandelic acid~0.35–0.8%
Key activeIrritant · high
Irritation risk
High
Works for
ExfoliationEvens skin toneAnti-blemishAntibacterial

Helps shed the upper layer of dead cells from the surface of the skin revealing smoother, brighter skin. It can help to reduce hyperpigmentation. It has anti-bacterial properties, and might help to reduce blemishes, as well as fine lines and wrinkles. It is considered to be gentler than glycolic acid

More about Mandelic acid
Chlamydomonas reinhardtii extract~0.3–0.75%
Formula
Helianthus annuus seed oil~0.35–0.8%
Key active
Irritation risk
Low
Works for
Moisturizing

A great emollient due to its high linoleic acid content. One of the most effective plant oils in helping skin hydration and repairing skin barrier function

More about Helianthus annuus seed oil
Disodium acetyl glucosamine phosphate~0.3–0.7%
Formula
Magnesium chloride~0.2–0.8%
Formula
Irritation risk
Low

Helps thicken the product formulation

More about Magnesium chloride
Melia azadirachta flower extract~0.15–0.7%
Irritant · medium
Irritation risk
Medium
Works for
Anti-oxidation

A plant extract that might be helpful to neutralize free radicals in skin

More about Melia azadirachta flower extract
Curcuma longa root extract~0.15–0.6%
Irritant · high
Irritation risk
High
Works for
Anti-inflammatory

A plant extract that can contain an active compound curcumin, that may have some anti-inflammatory properties when applied to the skin, but solid research is lacking and the typical concentration used in skincare products is too low. Can be an irritant

More about Curcuma longa root extract
Ginkgo biloba leaf extract~0.15–0.55%
Key activeIrritant · high
Irritation risk
High
Works for
Anti-oxidationAnti-blemishAntibacterialAnti-inflammatory

A plant extract that might help neutralize free radicals and reduce inflammation in skin. It can be irritating

More about Ginkgo biloba leaf extract
Avena sativa kernel extract~0.15–0.6%
Under-dosed
Irritation risk
Low
Works for
Anti-inflammatoryReduces irritationMoisturizingReduces rednessAnti-oxidation

An effective moisturizing and skin barrier repair ingredient. Helps calm down inflammation and has some anti-oxidant properties

More about Avena sativa kernel extract
Isoamyl cocoate~0.15–0.5%
Irritant · medium
Irritation risk
Medium

Helps oil and water mix together and works as a cleansing agent

More about Isoamyl cocoate
Lysolecithin~0.1–0.5%
Formula
Irritation risk
Low
Works for
CleansingMoisturizing

Lecithin derivative. It helps oil and water mix together and can enhance penetration of other ingredients. It helps soften the upper layer of the skin

More about Lysolecithin
Silica~0.2–0.7%
Formula
Irritation risk
Low

Used to absorb oil and can temporarily mattify skin

More about Silica
Sclerotium gum~0.1–0.35%
Formula
Irritation risk
Low

Used to create gel-like formulas and stabilize emulsions

More about Sclerotium gum
Potassium sorbate~0.05–0.3%
Irritant · medium
Irritation risk
Medium

A preservative

More about Potassium sorbate
Xanthan gum~0.05–0.3%
Formula
Irritation risk
Low
Works for
Cleansing

Used to create a thicker product consistency

More about Xanthan gum
Pullulan~0.05–0.25%
Irritant · high
Irritation risk
High
Works for
Mattifying

Creates a thin drying film on the skin resulting in a short-term tightening effect

More about Pullulan
Leuconostoc/radish root ferment filtrate~0.05–0.15%
Irritant · medium
Irritation risk
Medium

A preservative that comes from radishes fermented by a bacteria. New research suggests that the preservation properties in the ingredient come from an ammonium salt that is not present naturally in radish root but used in its cultivation. Is problematic because the exact amount of the preservative agents is difficult to determine

More about Leuconostoc/radish root ferment filtrate
Sodium hydroxide~0.05–0.15%
Formula
Irritation risk
Low

Used to adjust the product's pH

More about Sodium hydroxide
Ingredient list view

Water, Gluconolactone, Prunus persica kernel oil, Lactic acid, Glycerin, Isoamyl laurate, Simmondsia chinensis seed oil, Bentonite, Malic acid, Cetearyl olivate, Salicylic acid, Sorbitan olivate, Undaria pinnatifida cell culture extract, Mandelic acid, Chlamydomonas reinhardtii extract, Helianthus annuus seed oil, Disodium acetyl glucosamine phosphate, Magnesium chloride, Melia azadirachta flower extract, Curcuma longa root extract, Ginkgo biloba leaf extract, Avena sativa kernel extract, Isoamyl cocoate, Lysolecithin, Silica, Sclerotium gum, Potassium sorbate, Xanthan gum, Pullulan, Leuconostoc/radish root ferment filtrate, Sodium hydroxide

Compare prices

Retailers ranked by price — lowest first.

Holifrog
$58.00 Out of stock
Check

Affiliate links

Worth comparing, line by line.

Match % combines shared ingredients, the first five ingredients, shared actives and hero ingredients, irritancy (lower counts in the alternative's favour), texture and body area. Only products in the same routine step are compared.

Side-by-side comparison of this product against its closest alternatives
HoliFrogKosi Multi-Acid MaskYOUR PRODUCTDeviant SkincareGentle Resurfacing LiquidBe MinimalistAHA PHA BHA 32%GlossierSolution
Match—90%87%86%
Price—$52.00$15.65$30.00
Shared key ingredients—6 of 95 of 94 of 9
Key difference—Glycolic AcidGlycolic AcidNiacinamide
Irritancy Medium Low Low Low
Drying alcohol————
View product Shop Shop Shop

More alternatives: Naturopathica Sweet Cherry Brightening Enzyme PeelEcooking Peeling Mask

Cheaper alternatives? See how this stacks up against similar formulas.
We compare ingredient profiles across our catalog — pick the closest match for your budget.
Open dupe finder

Sources cited in this review

Every concentration estimate and effectiveness label is anchored to one of these 27 studies and safety reviews.

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
HoliFrog Kosi Multi-Acid Mask
HoliFrogKosi Multi-Acid Mask

Affiliate links · As an Amazon Associate, WIMJ earns from qualifying purchases.

As an Amazon Associate, WIMJ earns from qualifying purchases.