What is propanediol in skincare?
Propanediol – specifically 1,3-propanediol – is a small alcohol produced by fermenting corn sugar. It appears near the top of a great many ingredient lists because it does several unshowy jobs at once.
It is a humectant, a solvent for ingredients that will not dissolve in water alone, a preservative booster, and a texture agent that gives a formula its light, non-tacky slip. It is the plant-derived alternative brands reach for in place of propylene glycol.
What skin concerns does propanediol treat?
As a humectant it draws water into the stratum corneum, relieving dryness and tightness in any skin type. It is lightweight and non-comedogenic, so it suits oily and acne-prone skin as readily as dry.
Its more important function is enabling: it improves how well other actives penetrate and stay dissolved, so the salicylic acid or vitamin C beside it in the formula works better. Research on 1,3-propanediol covers exactly that role.
What ingredients are best paired with propanediol?
It carries and enhances actives across the board – salicylic acid, vitamin C, niacinamide, retinoids – and layers with glycerin and hyaluronic acid for hydration.
It is generally better tolerated than propylene glycol, which is a documented contact allergen, so it is the sensible choice for reactive skin. Seal it with a moisturiser as you would any humectant. Take our Skin Quiz.
What is oily skin?
Oily skin is a skin type in which the sebaceous glands produce more sebum than the skin needs. It shows up as shine through the T-zone within hours of cleansing, visibly enlarged pores, makeup that slides or separates, and a tendency towards blackheads and congestion.
Sebum itself is not the enemy – it carries vitamin E to the surface, keeps the barrier supple and helps oily skin hold its structure, which is why it often shows fine lines later than dry skin does.
What causes oily skin?
Genetics and androgen activity are the primary drivers of how much sebum your glands produce. Heat and humidity increase output measurably, and hormonal fluctuations across the monthly cycle, pregnancy or puberty shift it again.
Stress, a diet heavy in refined carbohydrates, and – counter-intuitively – over-cleansing with stripping foams or alcohol-based toners all push oil production up, because skin compensates for a damaged barrier by making more.
What ingredients are best for oily skin?
Look for salicylic acid (a BHA that is oil-soluble, so it clears inside the pore), niacinamide and zinc to regulate sebum, clay such as bentonite or kaolin for weekly absorption, and retinoids or azelaic acid to normalise how pores shed.
Do not skip hydration: lightweight humectants like hyaluronic acid and glycerin, plus non-comedogenic squalane or jojoba oil, keep the barrier intact so the skin stops over-compensating. Skip heavy occlusive balms and high-alcohol toners. Take our Skin Quiz to get the balance right for your skin.
