Bu
Butylene Glycol
Butylene GlycolHydrator
Mild humectant and solvent. The lower-irritation cousin of propylene glycol; common in K-beauty essences.
What it does
Butylene glycol is a four-carbon glycol that performs the same humectant and solvent functions as propylene glycol with a lower irritation profile. It's a frequent backbone of K-beauty essences and Western 'lightweight serum' formulations because it pulls water into the skin without the heavy or tacky feel of glycerin alone. Generally tolerated by sensitive skin types.
The evidence, graded
expert consensusThe traditional K-beauty 10-step layering approach (oil cleanser → foam cleanser → toner → essence → serum → ampoule → sheet mask → eye cream → moisturizer → SPF) is fully compatible with Western actives but not necessary for results. Adding more steps does not equal more efficacy.Draelos 2018 · Journal of Cosmetic Dermatology ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Also known as
bg
Pairs worth knowing
This page is public and indexed on purpose (unlike profiles and drops, which are unlisted) — it’s the citation behind shared ingredient cards, and it should be findable.
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