Malic acid

Malic acid is an alpha hydroxy acid (AHA) naturally found in apples, pears, and other fruits, known for its gentle exfoliating, hydrating, and brightening properties. Unlike stronger AHAs such as glycolic or lactic acid, malic acid has a larger molecular structure, which means it penetrates the skin more slowly, reducing the risk of irritation while still delivering effective exfoliation. This makes it a great option for those with sensitive or reactive skin who want to experience the benefits of chemical exfoliation without excessive dryness or redness.

One of malic acid’s key benefits is its ability to promote cell turnover, helping to smooth rough skin, fade discoloration, and improve overall radiance. It works by breaking down the bonds between dead skin cells, allowing them to shed more easily and reveal fresher, healthier skin underneath. Because it has both humectant and keratolytic properties, malic acid not only exfoliates but also attracts moisture to the skin, making it a hydrating AHA that helps maintain the skin’s natural moisture barrier.

Malic acid is often used in combination with other exfoliating acids, such as glycolic or lactic acid, in peels, cleansers, and serums to create a balanced exfoliation process. It is particularly effective for addressing concerns like dullness, fine lines, hyperpigmentation, and uneven skin tone, while also helping to refine the appearance of pores. Additionally, its antioxidant properties help protect the skin from oxidative stress and environmental damage.

While malic acid is considered one of the gentler AHAs, it can still increase sun sensitivity, so daily sunscreen use is essential when incorporating it into a skincare routine. It works well alongside hydrating ingredients like hyaluronic acid, ceramides, and soothing agents like aloe vera, making it a well-rounded ingredient for improving skin texture and radiance without excessive irritation.

Malic acid (Wikipedia)

Not to be confused with maleic acid or malonic acid.

"Malate" redirects here. For the district in Manila, see Malate, Manila.

Malic acid is an organic compound with the molecular formula HO₂CCH(OH)CH₂CO₂H. It is a dicarboxylic acid that is made by all living organisms, contributes to the sour taste of fruits, and is used as a food additive. Malic acid has two stereoisomeric forms (L- and D-enantiomers), though only the L-isomer exists naturally. The salts and esters of malic acid are known as malates. The malate anion is a metabolic intermediate in the citric acid cycle.

Malic acid

DL-Malic acid
Names
Preferred IUPAC name 2-Hydroxybutanedioic acid
Other names Hydroxybutanedioic acid 2-Hydroxysuccinic acid (L/D)-Malic acid (±)-Malic acid (S/R)-Hydroxybutanedioic acid
Identifiers
CAS Number	6915-15-7 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:6650 Y CHEBI:30796 D-(+) CHEBI:30797 L-(–)
ChEMBL	ChEMBL1455497 N
ChemSpider	510 Y 83793 D-(+)-malic acid Y 193317 L-(–)-malic acid Y
ECHA InfoCard	100.027.293
EC Number	230-022-8
E number	E296 (preservatives)
IUPHAR/BPS	2480
KEGG	C00711 N C00497 D-(+) C00149 L-(–)
PubChem CID	525 92824 D-(+) 222656 L-(–)
UNII	817L1N4CKP Y
CompTox Dashboard (EPA)	DTXSID0027640
InChI InChI=1S/C4H6O5/c5-2(4(8)9)1-3(6)7/h2,5H,1H2,(H,6,7)(H,8,9) Y Key: BJEPYKJPYRNKOW-UHFFFAOYSA-N Y InChI=1/C4H6O5/c5-2(4(8)9)1-3(6)7/h2,5H,1H2,(H,6,7)(H,8,9) Key: BJEPYKJPYRNKOW-UHFFFAOYAM
SMILES O=C(O)CC(O)C(=O)O
Properties
Chemical formula	C4H6O5
Molar mass	134.09 g/mol
Appearance	Colorless
Density	1.609 g⋅cm−3
Melting point	130 °C (266 °F; 403 K)
Solubility in water	558 g/L (at 20 °C)
Acidity (pKa)	pKa1 = 3.40 pKa2 = 5.20 pKa3 = 14.5
Hazards
GHS labelling:
Pictograms
Flash point	203 °C
Related compounds
Other anions	Malate
Related carboxylic acids	Succinic acid Tartaric acid Fumaric acid
Related compounds	Butanol Butyraldehyde Crotonaldehyde Sodium malate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references