What is butylene glycol in skincare?
Butylene glycol, or 1,3-butylene glycol, is a small alcohol used as a solvent, humectant and texture agent. Like propanediol and propylene glycol it is a workhorse rather than a star, appearing high on ingredient lists because formulas need it to function.
It dissolves ingredients that water alone cannot carry, thins heavy formulations to a pleasant consistency, and helps actives spread and penetrate evenly.
What skin concerns does butylene glycol treat?
It hydrates lightly by drawing water into the surface layers, and it is non-comedogenic and weightless, which makes it common in products aimed at oily and acne-prone skin.
Mostly, though, its value is what it enables: the vitamin C, salicylic acid or plant extract next to it in the formula reaches the skin in usable form. Allergic contact dermatitis to butylene glycol is documented but uncommon, and it is generally better tolerated than propylene glycol.
What ingredients are best paired with butylene glycol?
It pairs with essentially everything, and is most often seen alongside glycerin, hyaluronic acid and botanical extracts it helps keep in solution.
One thing worth knowing if you have reacted to propylene glycol: there is documented cross-reactivity between propylene glycol and butylene glycol, so a known allergy to one is a reason to patch test the other rather than assume it is safe. Take our Skin Quiz.
What are age spots?
Age spots – known clinically as solar lentigines, and sometimes as liver spots – are flat, well-defined brown or tan patches that appear on skin with the most cumulative sun exposure: the face, backs of the hands, forearms, shoulders and upper chest.
Despite the name, they are not caused by age itself. They are a record of ultraviolet exposure, which is why they are common from the forties onward and why they cluster on areas that rarely get sunscreen.
What causes age spots?
Long-term UV exposure drives melanocytes to over-produce melanin in concentrated spots, and the surrounding keratinocytes stop clearing that pigment efficiently as skin ages.
Fair skin, a history of sunburns, tanning beds and outdoor work all raise the risk. Any new spot that changes shape, colour or size, bleeds or has an irregular border should be checked by a doctor rather than treated cosmetically.
What ingredients are best for age spots?
Topical treatment works but needs patience – expect three to six months. Retinoids speed turnover so pigmented cells shed faster, vitamin C and niacinamide brighten and protect, and alpha arbutin, kojic acid, azelaic acid and liquorice root inhibit new pigment.
Glycolic or lactic acid helps lift existing pigment from the surface. Daily broad-spectrum SPF, including on hands and chest, is what prevents new spots forming. Take our Skin Quiz.
