Centellian24 The Madeca Cream

Centellian24 The Madeca Cream
5.0
/ 10
Moisturizing
6.5 Humectancy icon Humectancy
3.4 Occlusivity icon Occlusivity
5Anti-wrinkle icon/ 10
Anti-wrinkle
Rich
in Antioxidants

Review

Does Centellian24 The Madeca Cream work?

Based on the ingredient list analysis by CreamScan AI, these are the key benefits you can expect from using Centellian24 The Madeca Cream:

  • Moderate moisturizing. It has a moisturizing rating of 5.0 out of 10.
  • Considerable anti-wrinkle efficacy: Centellian24 The Madeca Cream has an anti-wrinkle rating of 5.0 out of 10, indicating a moderate ability to reduce wrinkles.
  • Antioxidant protection.

How moisturizing is it?

Quite moisturizing: Centellian24 The Madeca Cream has a moisturizing rating of 5.0 out of 10.

Is it more humectant or occlusive? Rather humectant. It has a high humectancy of 6.5 out of 10, primarily due to the substantial concentration of Glycerin (est. ≈2.5%), and a moderate occlusivity of 3.4 out of 10, mainly due to the significant content of Caprylic/Capric Triglyceride (est. ≈4.0%).

Please refer to the Ratings section below for details of the moisturizing rating calculation.

Anti-wrinkle efficacy

According to CreamScan analysis, Centellian24 The Madeca Cream has a moderate anti-wrinkle rating of 5.0 out of 10.

It contains 2 active ingredients with proven anti-wrinkle efficacy:

  • Asiaticoside (est. ≈0.3%),
     derived from the plant Centella asiatica, an ingredient with moderate anti-wrinkle efficacy confirmed by one study.
  • Niacinamide (est. ≈1.3%),
     one of the most effective and well-researched anti-wrinkle ingredients.
Among others, Centellian24 The Madeca Cream also contains some ingredients marketed as effective in reducing wrinkles, specifically Centella Asiatica Leaf Extract, Ascorbyl Palmitate, Madecassic Acid, Asiatic Acid, and Adenosine. However, the studies supporting the anti-wrinkle claims of these ingredients provide insufficient evidence of efficacy according to CreamScan Research Evaluation Standards. Therefore, these ingredients do not contribute to the anti-wrinkle rating.
 
Moisturizers, when used regularly, are proven to prevent wrinkle formation and even reduce existing wrinkles. Therefore, this product, like any other moisturizer, could deliver additional anti-wrinkle efficacy through its moisturizing action.
 

Please refer to the Ratings section below for details of the anti-wrinkle rating calculation.

Antioxidant benefits

We estimate that Centellian24 The Madeca Cream is rich (> 3%) in antioxidants, specifically Niacinamide (est. ≈1.3%), Centella Asiatica Leaf Extract (est. ≈0.3%), Olea Europaea (Olive) Fruit Oil (est. ≈0.3%), and others.

A key benefit of antioxidants is their ability to reduce oxidative stress caused by free radicals and therefore prevent accelerated skin aging. Studies also show that antioxidants can protect against environmental damage such as UV radiation and pollution, and help reduce inflammation and skin redness.

Ingredients

Est. % Ingredient Origin Functions
55
9
6
4
3
2.5
2
1.5
1.3
1
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
Est. %
Lactobacillus/Centella Asiatica Extract Ferment Filtrate
Function:
Origin:
Dipropylene Glycol
Function:
Origin:
Hydrogenated Polydecene
Function:
Origin:
Caprylic/Capric Triglyceride
Function:
Origin:
Cyclohexasiloxane
Function:
Origin:
Glycerin
Function:
Origin:
Glyceryl Stearate
Function:
Origin:
Pentaerythrityl Tetraethylhexanoate
Function:
Origin:
Niacinamide
Function:
Origin:
Polyglyceryl-6 Distearate
Function:
Origin:
Cetyl Alcohol
Function:
Origin:
Dicaprylyl Ether
Function:
Origin:
Centella Asiatica Leaf Extract
Function:
Origin:
Olea Europaea (Olive) Fruit Oil
Function:
Origin:
Centella Asiatica Oil
Function:
Origin:
Hydrolyzed Corn Protein
Function:
Origin:
Ascorbyl Palmitate
Function:
Origin:
Ceramide NP
Function:
Origin:
Collagen Amino Acids
Function:
Origin:
Sodium Starch Octenylsuccinate
Function:
Origin:
Macadamia Ternifolia Seed Oil
Function:
Origin:
Hydrogenated Lecithin
Function:
Origin:
Sodium Hyaluronate
Function:
Origin:
Polyglyceryl-10 Laurate
Function:
Origin:
Beeswax
Function:
Origin:
Sodium Stearoyl Glutamate
Function:
Origin:
Panthenol
Function:
Origin:
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Function:
Origin:
Madecassic Acid
Function:
Origin:
Asiaticoside
Function:
Origin:
Jojoba Esters
Function:
Origin:
Butylene Glycol
Function:
Origin:
Dimethicone/Vinyl Dimethicone Crosspolymer
Function:
Origin:
Asiatic Acid
Function:
Origin:
Polyglyceryl-3 Beeswax
Function:
Origin:
Allantoin
Function:
Origin:
Candida/Garcinia Cambogia Ferment
Function:
Origin:
Xanthan Gum
Function:
Origin:
Adenosine
Function:
Origin:
Sorbitan Isostearate
Function:
Origin:
Sodium Laurate
Function:
Origin:
Lauric Acid
Function:
Origin:
Tromethamine
Function:
Origin:
Citric Acid
Function:
Origin:
Glycine
Function:
Origin:
Glutamic Acid
Function:
Origin:
1,2-Hexanediol
Function:
Origin:
Phytosphingosine
Function:
Origin:
Ethylhexylglycerin
Function:
Origin:
Water
Function:
Origin:
Stearyl Alcohol
Function:
Origin:
Disodium EDTA
Function:
Origin:
Pelargonium Graveolens Flower Oil
Function:
Origin:
Citrus Aurantium Dulcis (Orange) Peel Oil
Function:
Origin:
Eucalyptus Globulus Leaf Oil
Function:
Origin:
Lavandula Angustifolia (Lavender) Oil
Function:
Origin:
Limonene
Function:
Origin:
Citronellol
Function:
Origin:
Linalool
Function:
Origin:
Geraniol
Function:
Origin:

Ratings

All humectants
6.5
2.5
1.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
Benchmark
10
All occlusives
6.7
4.0
1.5
0.3
0.3
0.3
0.3
Benchmark
20
Moisturizing rating
5.0
Ingredient Est. % Benchmark Raiting
Humectancy All humectants 6.5 10
6.5
2.5
1.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
Occlusivity All occlusives 6.7 20
3.4
4.0
1.5
0.3
0.3
0.3
0.3
Moisturizing rating
5.0
Ingredient Est. % Benchmark Humectancy
2.5
1.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
All humectants 6.5 10
6.5
All humectants
6.5
2.5
1.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
Benchmark
10
Ingredient Est. % Benchmark Occlusivity
4
1.5
0.3
0.3
0.3
0.3
All occlusives 6.7 20
3.4
All occlusives
6.7
4.0
1.5
0.3
0.3
0.3
0.3
Benchmark
20
Ingredient
Ingredient anti-wrinkle power
when present at, %
in this formula est. %
Rating
3 /10 0.1 0.3 3
6 /10 4 1.3 2
n/a
- 0.3 -
n/a
- 0.3 -
n/a
- 0.3 -
n/a
- 0.3 -
n/a
- 0.3 -
Total
5
Asiaticoside
3
Ingredient anti-wrinkle power
3 /10
when present at, %
0.1
in this formula, est. %
0.3
Niacinamide
2
Ingredient anti-wrinkle power
6 /10
when present at, %
4
in this formula, est. %
1.3
Centella Asiatica Leaf Extract
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Ascorbyl Palmitate
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Madecassic Acid
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Asiatic Acid
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Adenosine
-
Ingredient anti-wrinkle power
n/a
when present at, %
-
in this formula, est. %
0.3
Anti-wrinkle rating
5
Ingredient Est. % Benchmark
Rich in Antioxidants
1.3
0.3
0.3
0.3
0.3
0.3
0.3
All antioxidants 3.1 3 Rich in antioxidants
All antioxidants
3.1
Niacinamide
1.3
Asiaticoside
0.3
Centella Asiatica Leaf Extract
0.3
Olea Europaea (Olive) Fruit Oil
0.3
Centella Asiatica Oil
0.3
Ascorbyl Palmitate
0.3
Sodium Hyaluronate
0.3
Benchmark
3
Ingredient Est. % Benchmark
Rich in Soothing
1.3
0.3
0.3
0.3
0.3
0.3
All soothing 2.8 5 No
All soothing
2.8
1.3
0.3
0.3
0.3
0.3
0.3
Benchmark
5

Ingredients explained

Lactobacillus/Centella Asiatica Extract Ferment Filtrate
Est. %55
Function
Origin
Lactobacillus/Centella Asiatica Extract Ferment Filtrate
Dipropylene Glycol
Est. %9
Function
Origin
Dipropylene GlycolA clear, colorless liquid that has several uses. One of its main functions is as a solvent. Dipropylene glycol is also used to reduce the thickness of skincare products.
Hydrogenated Polydecene
Est. %6
Function
Origin
Hydrogenated PolydeceneA clear, colorless, highly viscous liquid that commonly serves as an emollient. This rich emollient is on the heavier side but provides a smooth sensorial profile upon application.
Caprylic/Capric Triglyceride
Est. %4
Function
Origin
Caprylic/Capric TriglycerideA natural occlusive moisturizing and emollient ingredient, it is a blend of glycerin and two fatty acids, caprylic and capric acid. It creates an oil-based protective layer on the skin, thereby preventing water loss.
Cyclohexasiloxane
Est. %3
Function
Origin
CyclohexasiloxaneA clear silicone fluid with very low viscosity that is commonly used as a solvent and emollient. It has excellent spreadability, rubs in quickly, and leaves a silky smooth after-feel on the skin.
Glycerin
Est. %2.5
Function
Origin
Glycerin

The most popular moisturizing ingredient in the world. It is a powerful humectant – cheap yet very effective.

Glyceryl Stearate
Est. %2
Function
Origin
Glyceryl StearateAn emollient and emulsifier typically derived from vegetable sources through a chemical reaction with glycerin. It provides stability, texture, and consistency to formulations. Its main function is to allow oil and water to mix.
Pentaerythrityl Tetraethylhexanoate
Est. %1.5
Function
Origin
Pentaerythrityl TetraethylhexanoateAn occlusive moisturizer and emollient with a good lubricity that leaves behind a glossy sheen after application. It can also control viscosity by thickening skincare products and act as a binding agent to hold pressed powdered products together.
Niacinamide
Est. %1.3
Function
Origin
Niacinamide

Also known as vitamin B3, this ingredient is a true superstar with confirmed moisturizing, anti-acne, hyperpigmentation, and antioxidant benefits. Two studies confirm its significant anti-wrinkle efficacy.

Polyglyceryl-6 Distearate
Est. %1
Function
Origin
Polyglyceryl-6 Distearate
Cetyl Alcohol
Est. %0.3
Function
Origin
Cetyl AlcoholA waxy solid fatty alcohol derived from palm oil. It is most commonly used as a co-emulsifier and affects the final aesthetic of the product, leaving a soft and silky feeling on the skin. Cetyl alcohol is also used as a viscosity controlling agent.
Dicaprylyl Ether
Est. %0.3
Function
Origin
Dicaprylyl EtherA fast-spreading and very lightweight emollient. It is used to reduce the tack and oiliness of oil-based formulas and gives the skin a dry, silky after-feel. It is also a great solvent.
Centella Asiatica Leaf Extract
Est. %0.3
Function
Origin
Centella Asiatica Leaf ExtractA well-researched soothing, wound-healing, and promising anti-aging extract that is obtained from the leaves of the Gotu Kola.
Olea Europaea (Olive) Fruit Oil
Est. %0.3
Function
Origin
Olea Europaea (Olive) Fruit Oil

A famous olive oil widely used in skincare as an emollient and occlusive moisturizer. It contains mainly unsaturated fatty acids, antioxidant flavonoids, and oleuropeins. Olive oil is listed as a common comedogenic ingredient by acne.org.

Centella Asiatica Oil
Est. %0.3
Function
Origin
Centella Asiatica Oil
Hydrolyzed Corn Protein
Est. %0.3
Function
Origin
Hydrolyzed Corn Protein
Ascorbyl Palmitate
Est. %0.3
Function
Origin
Ascorbyl PalmitateA form of vitamin C derived from ascorbic acid and palmitic acid. It is more stable and less irritating than ascorbic acid. Unfortunately, Ascorbyl Palmitate lacks the studies to prove its anti-wrinkle efficacy.
Ceramide NP
Est. %0.3
Function
Origin
Ceramide NPAlso known as ceramide 3, it is the most common ceramide in our skin. It helps to restore the skin’s lipid barrier and alleviate the symptoms of dry and cracked skin. Research has shown that skin suffering from conditions such as AD lacks ceramides.
Collagen Amino Acids
Est. %0.3
Function
Origin
Collagen Amino AcidsA mixture of amino acids obtained by chopping up collagen molecules. It consists mainly of glycine, proline, alanine, and hydroxyproline. They all have humectant properties.
Sodium Starch Octenylsuccinate
Est. %0.3
Function
Origin
Sodium Starch Octenylsuccinate
Macadamia Ternifolia Seed Oil
Est. %0.3
Function
Origin
Macadamia Ternifolia Seed OilAn occlusive moisturizing and emollient oil extracted from macadamia nuts. It is clear and pale yellow with a pleasant nutty aroma and contains oleic and palmitoleic fatty acids, tocopherols, phytosterols, squalene, and polyphenols.
Hydrogenated Lecithin
Est. %0.3
Function
Origin
Hydrogenated LecithinA version of plain lecithin that has been saturated with hydrogen atoms. This ingredient can be derived from plants, like soy or sunflower, from egg yolks, or made synthetically. Its major function is to emulsify water and oils.
Sodium Hyaluronate
Est. %0.3
Function
Origin
Sodium Hyaluronate

A sodium salt of famous hyaluronic acid. A potent humectant that hydrates the skin, supports collagen function, and fills out small wrinkles. Sodium hyaluronate also offers soothing and antioxidant properties.

Polyglyceryl-10 Laurate
Est. %0.3
Function
Origin
Polyglyceryl-10 LaurateA vegetable glycerin or synthetically produced emulsifier and gentle cleansing agent. It won't leave skin feeling tight or dry when used to cleanse.
Beeswax
Est. %0.3
Function
Origin
BeeswaxA waxy substance made by bees while they are building their honeycombs. It is an occlusive moisturizing and emollient ingredient with wound healing and antimicrobial properties similar to those of honey. Its bleached, purified form is called Cera alba.
Sodium Stearoyl Glutamate
Est. %0.3
Function
Origin
Sodium Stearoyl GlutamateA useful ingredient for both cleansing and emulsifying purposes. It is a powerful agent for washing away dirt and oils from the skin.
Panthenol
Est. %0.3
Function
Origin
PanthenolA popular soothing and moisturizing derivative of vitamin B5. Panthenol is particularly beneficial for dry, flaking, burned, or damaged skin. It is used to alleviate the symptoms of a rash, dermatitis, eczema, chapped lips, and sunburn.
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Est. %0.3
Function
Origin
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate CopolymerAn emulsion stabilizer and thickener that helps to create a pleasant, satiny, and light formula texture. It works by forming a gel-like network within water or oil, which both stabilizes other ingredients and produces a thickening effect.
Madecassic Acid
Est. %0.3
Function
Origin
Madecassic AcidAn isolated bioactive compound from Gotu Kola. It increases collagen and hyaluronic acid production in the skin and helps to treat wounds, scars, and burns.
Asiaticoside
Est. %0.3
Function
Origin
Asiaticoside

A Gotu Kola or Centella Asiatica derivative with confirmed anti-wrinkle efficacy.

Jojoba Esters
Est. %0.3
Function
Origin
Jojoba EstersA mixture of various wax esters from jojoba oil. It is used in skincare products as a fantastic emollient, soothing, and occlusive moisturizing agent that won't leave a sticky, oily feeling on the skin.
Butylene Glycol
Est. %0.3
Function
Origin
Butylene Glycol

A clear, colorless liquid humectant that draws moisture to the skin. The humectancy of butylene glycol, owed to its two hydroxyl groups, is quite considerable, although not as powerful as glycerin, which contains three hydroxyl groups.

Dimethicone/Vinyl Dimethicone Crosspolymer
Est. %0.3
Function
Origin
Dimethicone/Vinyl Dimethicone CrosspolymerThis ingredient can refer to several kinds of dimethicone crosspolymers. Like other silicones, it makes products feel slippery and non-greasy but can also increase the thickness or improve the water-resistance of a formula.
Asiatic Acid
Est. %0.3
Function
Origin
Asiatic AcidA compound isolated from Gotu Kola, a promising anti-wrinkle medicinal plant from Southeast Asia. It is claimed to increase the production of collagen and help with the wound healing process.
Polyglyceryl-3 Beeswax
Est. %0.3
Function
Origin
Polyglyceryl-3 Beeswax
Allantoin
Est. %0.3
Function
Origin
AllantoinA fluffy, white powder that acts as a humectant due to its water-loving chemistry and as an exfoliant that helps to remove dead skin cells. It has also been shown to be very soothing to irritated and inflamed skin.
Candida/Garcinia Cambogia Ferment
Est. %0.3
Function
Origin
Candida/Garcinia Cambogia Ferment
Xanthan Gum
Est. %0.3
Function
Origin
Xanthan GumA natural multi-functional ingredient that originates from fermented sugars. Xanthan gum acts as a viscosity-building agent to thicken skincare products. It is also an excellent stabilizer and works well to hold other ingredients together.
Adenosine
Est. %0.3
Function
Origin
Adenosine

A key molecule responsible for energy transportation, signaling, and enzyme activity. Adenosine is a popular anti-wrinkle ingredient, however, the key study about its anti-wrinkle efficacy (1) does not meet CreamScan Research Evaluation Standards as it is not double-blind.

Sorbitan Isostearate
Est. %0.3
Function
Origin
Sorbitan IsostearateA mild yet powerful emulsifier primarily utilized to produce water-in-oil emulsions. It helps to create a particularly rich and substantial emulsion.
Sodium Laurate
Est. %0.3
Function
Origin
Sodium Laurate
Lauric Acid
Est. %0.3
Function
Origin
Lauric AcidA fatty acid derived from various vegetable oils such as palm or coconut oil. It helps to maintain the barrier function of the skin and is also used as a cleansing or emulsifying agent. Lauric acid is listed among common comedogenic ingredients by acne.org.
Tromethamine
Est. %0.3
Function
Origin
TromethamineAn ingredient based on amino acids that is commonly used as a pH adjuster. It has a high pH, which means that it is basic (alkaline), so adding tromethamine to a skincare product will increase its overall pH level.
Citric Acid
Est. %0.3
Function
Origin
Citric AcidA gently exfoliating AHA that helps to remove the top layer of dead skin cells. In comparison to other AHAs, citric acid has been shown to be one of the least effective. It is also very commonly used as a stabilizing and pH-controlling agent.
Glycine
Est. %0.3
Function
Origin
GlycineA humectant moisturizing amino acid that is a part of skin's Natural Moisturizing Factor. Some recent studies suggest that it may have barrier repair properties.
Glutamic Acid
Est. %0.3
Function
Origin
Glutamic AcidA non-essential amino acid that serves as a building block for all proteins in the body. It is a moisturizing humectant and a part of the skin's Natural Moisturizing Factor, a mixture of amino acids in skin cells that keeps them hydrated.
1,2-Hexanediol
Est. %0.3
Function
Origin
1,2-HexanediolA multi-functional formula helper. It is a well-studied preservtive against bacteria and can help pigments and fragrances disperse evenly in a formula.
Phytosphingosine
Est. %0.3
Function
Origin
PhytosphingosineA key component of ceramides NP, AP, and EOP. It has barrier repair properties and stimulates the production of the skin’s Natural Moisturizing Factor. Phytosphingosine has strong antimicrobial and anti-inflammatory activity, which can be used to treat acne.
Ethylhexylglycerin
Est. %0.3
Function
Origin
EthylhexylglycerinA preservative booster derived from glycerin. It is commonly paired with other preservatives to improve their efficacy. Ethylhexylglycerin is also a humectant due to its chemical base of glycerin.
Water
Est. %0.3
Function
Origin
WaterThe most used ingredient in skincare. Its concentration defines the product texture: rich creams may have about 50% of water while a light jelly about 90%. Water doesn’t moisturize the skin by itself and is used in skincare as a solvent for other ingredients.
Stearyl Alcohol
Est. %0.3
Function
Origin
Stearyl AlcoholA natural fatty alcohol that thickens, stabilizes, and keeps emulsions a bright white color. It has many uses, the main one being as an emulsifier. It also acts as an opacifying agent and emollient.
Disodium EDTA
Est. %0.3
Function
Origin
Disodium EDTAA synthetic chelator that helps to maintain the look and smell of a product by 'locking up' troublesome metal ions.
Pelargonium Graveolens Flower Oil
Est. %0.3
Function
Origin
Pelargonium Graveolens Flower OilA fragrant essential oil with a distinct, rose-like scent derived from rose geranium. It is widely used in aromatherapy and massage therapy to ease tension. People with sensitive skin should try to avoid it, or at least do a patch test before using it.
Citrus Aurantium Dulcis (Orange) Peel Oil
Est. %0.3
Function
Origin
Citrus Aurantium Dulcis (Orange) Peel Oil

An essential oil derived from the peels of the sweet orange. It is commonly used as a fragrance because of its pleasant, citrusy scent. The main constituent of the essential oil is limonene (up to 96%).

Eucalyptus Globulus Leaf Oil
Est. %0.3
Function
Origin
Eucalyptus Globulus Leaf OilAn essential oil extracted from the leaves of the Eucalyptus globulus, a tall, evergreen, Australian tree with waxy leaves. It mostly consists of cineole – which has potent antimicrobial and anti-inflammatory activity.
Lavandula Angustifolia (Lavender) Oil
Est. %0.3
Function
Origin
Lavandula Angustifolia (Lavender) OilAn essential oil derived from common, or true, lavender. It is used in skincare for its lovely, calming scent. Like all essential oils, however, it may cause a contact skin allergy in more sensitive individuals.
Limonene
Est. %0.3
Function
Origin
Limonene

One of the most used fragrances in skincare products. It is produced from the peels of citrus fruits and has a fresh, pleasant, citrusy smell. People who are sensitive to citrus should try to avoid it, or at least do a patch test before using it.

Citronellol
Est. %0.3
Function
Origin
Citronellol

A fragrant compound found naturally in many essential oils (mainly lemongrass). It can have a lemon or a rose scent. People with sensitive skin should try to avoid products with citronellol, or at least do a patch test before using it.

Linalool
Est. %0.3
Function
Origin
LinaloolA fragrant, volatile compound naturally present in many essential oils. It has a pleasant scent and is often used in skincare products as a fragrance. People with sensitive skin should try to avoid it, or at least do a patch test before using it.
Geraniol
Est. %0.3
Function
Origin
Geraniol

A fragrant, volatile, plant-based, liquid chemical that can be naturally found in many essential oils (specifically rose, palmarosa, citronella). It has a rose-like scent. It is a potential irritant and may cause an allergic reaction in some people.