Gl
Glycerin
GlycerinHydrator
Cheap, ubiquitous, well-tolerated humectant. The workhorse moisturizing ingredient.
What it does
Glycerin draws water into the stratum corneum and is one of the most studied skincare ingredients in existence. Tolerance profile is excellent. Common in everything from drugstore cleansers to high-end serums.
The evidence, graded
strongHydrating ingredients (hyaluronic acid, glycerin) show immediate plumping and dewy-finish effects within minutes. Barrier-repair products (ceramides, panthenol, niacinamide-as-barrier) show measurable improvement in 1–2 weeks.Pavicic 2011 · Journal of Drugs in Dermatology ↗
emergingHyaluronic acid, polyglutamic acid, and glycerin pull and hold water through different mechanisms and at different skin depths. Stacking them gives surface-and-deeper hydration that any one humectant struggles to deliver alone.Papakonstantinou 2012 · Dermato-Endocrinology ↗
emergingHumectants like hyaluronic acid and glycerin work best on skin that's damp — not dripping wet, not bone-dry. The humectant needs a local water source to bind. Apply within ~60 seconds of cleansing or after a hydrating mist, then seal with a moisturizer. Apply on fully dry skin in low humidity with no seal and the humectant has little to hold, so it may underperform.Papakonstantinou 2012 · Dermato-Endocrinology ↗
emergingSome occlusives (cocoa butter, coconut oil, isopropyl myristate, certain plant butters) can be comedogenic on acne-prone skin. Lighter occlusives (squalane, mineral oil, hyaluronic acid, glycerin) are generally non-comedogenic in published data.Kligman 1972 · Archives of Dermatology ↗
emergingGlycerin improves stratum corneum hydration and barrier function and protects against irritating stimuli, making it well-tolerated.Fluhr 2008 · The British journal of dermatology ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Pairs worth knowing
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