INCI: Propanediol - Also known as: 1,3-Propanediol, Zemea Propanediol, Bio-PDO

QUICK FACTS

What is Propanediol?

Propanediol (1,3-propanediol) is a glycol - a class of short-chain alcohols with two hydroxyl groups - derived through bio-fermentation of corn-derived sugars. Unlike propylene glycol, its conventional synthetic counterpart, propanediol is produced via a renewable, corn-based fermentation process that is both more sustainable and associated with a lower skin irritation profile. It is commonly marketed under the trade name Zemea, which denotes the bio-based, non-GMO fermentation origin.

In skincare formulation, propanediol is valued for its multifunctional character. It functions simultaneously as a humectant, a solvent for actives and fragrance materials, a penetration-supporting glycol, and a mild antimicrobial co-preservative. This combination of roles in a single ingredient reduces the need for multiple specialized additives and allows formulators to achieve more streamlined ingredient lists without compromising on performance. At Sweet Chemistry, where every ingredient position in the formula is intentional, propanediol earns its place by performing across several functions at once.

It is present in all four Sweet Chemistry formulas, including the waterless Oil-Serum where it is listed as 1,3-Propanediol and functions specifically as a solubilizer and actives dispersant within the anhydrous base.

What does it do for skin?

As a humectant, propanediol is studied in connection with drawing moisture toward the skin's surface and supporting the overall hydration environment of a formula - working alongside glycerin, sodium PCA, and hyaluronic acid in the water-based formulas to contribute to the layered humectant system. While it is not as potent a single-ingredient humectant as sodium hyaluronate or glycerin, its contribution as part of a comprehensive humectant network adds to the formula's cumulative water-binding capacity.

As a solvent, propanediol supports the even dissolution and distribution of difficult-to-solubilize actives, particularly peptides and certain antioxidants that require a glycol-assisted solution environment. This solubilizing function is relevant in formulas with high active loads - at 40-46% active concentration across the Sweet Chemistry water-based products, maintaining clean, homogenous dissolution of all actives without phase separation or precipitation is a formulation priority that propanediol directly supports.

As a penetration-supporting glycol, propanediol is studied in connection with temporarily increasing the permeability of the stratum corneum to certain actives - an effect attributed to the glycol's interaction with the lipid bilayer that transiently makes the barrier more accessible to hydrophilic molecules. In the context of a formula delivering Matrikynes® peptides and niacinamide, this is a relevant property that may support the availability of water-soluble actives at the skin interface.

FOUND IN

In All 4 Formulas

Propanediol is the only glycol present across the entire Sweet Chemistry Max Repair System. Its presence in both the water-based formulas (as a humectant and solvent) and the Oil-Serum (as a solubilizer within the anhydrous base) reflects its versatility across formula architectures.

Nourishment - All Skin Types

Barrier Repairing Hydra-Serum Propanediol - 1.0 oz / 30 ml

In the Hydra-Serum, propanediol supports the dissolution of actives including niacinamide and the peptide complex within the 40%-active, water-based emulsion.

Hydration - Dry to Normal

Elasticity Reinforcing Hydra-Cream Propanediol - 1.7 oz / 50 ml

In the Hydra-Cream, propanediol contributes humectant and solvent support within a 40%-active emulsion that carries 3% Matrikynes® peptides, 2% THD ascorbate, and the full ceramide barrier complex.

Hydration - Dry to Dehydrated

Elasticity Reinforcing Lipid-Cream Propanediol - 1.7 oz / 50 ml

In the Lipid-Cream, propanediol supports active solubilization within the richest formula in the lineup - alongside shea butter, ceramides, and 3% Matrikynes® peptides.

Nourishment - Dry to Combination

Barrier Repairing Oil-Serum 1,3-Propanediol - 1.0 oz / 30 ml

In the waterless Oil-Serum, propanediol functions as a solubilizer within the anhydrous base - supporting the distribution of the ceramide complex, Matrikynes® peptides, and CoQ10 throughout the lipid-phase formula.

WORKS TOGETHER WITH

Organic Humectant Glycerin

INCI: Glycerin.

The primary humectant in Sweet Chemistry's three water-based formulas, listed near the top of the ingredient list. Synergy Note: Glycerin and propanediol are both polyols with humectant character - glycerin is the more potent individual water-binder, while propanediol's smaller molecular profile contributes a lighter, faster-absorbing hydration contribution that complements glycerin's deeper moisture draw.

NMF Component PCA (Pyrrolidone Carboxylic Acid)

INCI: PCA.

Present in all three water-based formulas as a skin-identical NMF component. Synergy Note: PCA contributes the skin's own NMF-based water-binding character; propanediol adds a glycol-based humectant layer that also supports active solubilization - together they address both skin-identical moisture management and formula performance.

Preservative Phenoxyethanol

INCI: Phenoxyethanol.

Present in all three water-based formulas as the primary preservative. Synergy Note: Propanediol functions as a mild co-preservative alongside phenoxyethanol - together they contribute a synergistic preservation environment that may support efficacy at lower concentrations of each individual component.

ECM Peptide Complex Matrikynes® Bone Peptides

INCI: Hydrolyzed Cow Bone Extract.

At 3% in all four formulas, associated with improvements in the appearance of skin density and aging signs. Synergy Note: Propanediol's solvent function supports the clean dissolution and even distribution of the Matrikynes® peptide complex throughout the formula - a formulation-level contribution to ensuring the peptide system delivers consistently with every application.