Succinic Acid

Succinic Acid is a naturally occurring dicarboxylic acid that plays a fascinating role in both biology and cosmetics. It is produced as an intermediate in the Krebs cycle (also known as the citric acid cycle), which is the metabolic pathway that generates energy in every living cell—from plants to animals to humans. In nature, you can find succinic acid in amber (its name comes from the Latin word "succinum," meaning amber), as well as in various fruits like apples, grapes, and rhubarb, and even in fermented products like cheese and sauerkraut. Chemically, it is a small molecule with two carboxylic acid groups (HOOC-CH₂-CH₂-COOH), which gives it unique buffering and exfoliating properties that set it apart from more common alpha-hydroxy acids (AHAs) like glycolic or lactic acid. Its ability to exist in a pure, crystalline form makes it stable and easy to incorporate into formulations, though it is most often used in concentrations ranging from 0.5% to 2% for skincare benefits.

In cosmetics, succinic acid serves dual primary functions: it acts as a buffering agent to stabilize a product’s pH and as a masking agent to help hide or neutralize unpleasant odors from other ingredients. However, its most interesting cosmetic role is as a gentle exfoliant that works differently from traditional AHAs. Unlike glycolic acid, which penetrates deeply and rapidly to dissolve desmosomes (the "glue" between dead skin cells), succinic acid operates more superficially—it targets the uppermost layers of the stratum corneum without causing the same level of irritation or pH drop. Formulators often use it at a pH around 4.0 to 5.5, which is closer to the skin’s natural pH, making it ideal for sensitive or reactive skin types. Additionally, succinic acid has demonstrated antimicrobial activity, particularly against bacteria like Propionibacterium acnes and Staphylococcus epidermidis, which is why it’s increasingly found in formulations targeting acne and blemishes. Typical concentrations are low—usually under 2% for leave-on products—because higher amounts can still cause stinging, though its overall irritation potential is significantly lower than that of AHAs or beta-hydroxy acids (BHAs).

The primary benefits of succinic acid in skincare are threefold: gentle exfoliation, acne-fighting action, and improved skin barrier function. As an exfoliant, it helps loosen and shed dead skin cells without the redness or peeling often associated with stronger acids, leading to a smoother, more even texture over time. For acne-prone skin, its antimicrobial properties are particularly valuable—research shows it can reduce the population of acne-causing bacteria while also calming inflammation, which is a key factor in breakouts. A 2017 study published in the International Journal of Dermatology found that a formulation containing 1% succinic acid significantly reduced both inflammatory and non-inflammatory acne lesions after four weeks, with minimal side effects. Additionally, succinic acid may support the skin’s natural barrier by promoting the production of ceramides and other lipids, thanks to its role in cellular energy metabolism—though this effect is less documented than its exfoliating and antimicrobial actions. While the evidence is not as extensive as for salicylic acid or benzoyl peroxide, the combination of mild exfoliation and antibacterial activity makes it a promising alternative for those who cannot tolerate harsher acne treatments.

Succinic acid is particularly well-suited for sensitive, reactive, or acne-prone skin because of its low irritation profile and ability to work without disrupting the skin’s moisture barrier. It pairs excellently with other gentle active ingredients like niacinamide, azelaic acid, or zinc, which can enhance its antibacterial and anti-inflammatory effects without causing over-exfoliation. However, it should not be combined with strong AHAs or BHAs in the same routine unless the formulation is specifically designed for that purpose, as this could increase irritation risk. One limitation is that succinic acid is less potent than traditional exfoliants, so it may not deliver dramatic results for those with severe hyperpigmentation or deep wrinkles—it’s more of a maintenance or maintenance-and-gentle-improvement ingredient. It is generally safe for all skin types, but if you have extremely dry or compromised skin, it’s best to start with a low-concentration product (around 0.5%) and patch test first. Pregnant or nursing individuals can use it safely, as it does not have the same concerns as retinoids or high-dose salicylic acid.

When shopping for products containing succinic acid, look for it listed near the middle or end of the ingredient list, as it is typically used in low concentrations. It often appears in serums, cleansers, and spot treatments marketed for acne or "blemish-prone" skin, sometimes alongside other mild acids like azelaic acid or salicylic acid in lower doses. One interesting fact: succinic acid is a key component in the production of biodegradable plastics, and its use in cosmetics reflects a broader trend toward sustainable ingredients derived from renewable resources. It also has a slightly sour, acidic taste—though you’ll never encounter that in skincare!—and is approved by the FDA as a food additive (E363) for its flavor-enhancing and pH-adjusting properties. In terms of texture, products with succinic acid often feel lightweight and non-sticky, making them a good choice for oily or combination skin. If you’re new to acids or have struggled with irritation from other exfoliants, starting with a succinic acid product can be a gentle way to introduce chemical exfoliation into your routine without overwhelming your skin.