Polybutene

Polybutene is a thick, clear, synthetic liquid polymer that forms the base of most lip glosses, giving the film its high shine and cushioned feel, and giving gloss its sticky pull when used at a high dose.

Also known as: hydrogenated polyisobutene, polyisobutene, PIB, gloss base

Polybutene is a polymer of butene, a small hydrocarbon, joined into long chains that behave like a very viscous, colourless oil. It does not evaporate, does not go rancid and does not absorb into skin, so it stays on the lip as a glassy film. Classic gloss was historically built on lanolin and polybutene, and it needs less wax than a lipstick because the base is free-flowing¹.

On an ingredient list it appears as polybutene or as its cousin hydrogenated polyisobutene, which is the same idea with the double bonds saturated for stability. Fenty Gloss Bomb lists polybutene first, ahead of octyldodecanol and shea butter², and Tower 28 ShineOn Lip Jelly combines polybutene and hydrogenated polyisobutene with five plant oils³.

The same property that gives shine gives stickiness. The long chains resist flowing, so lips feel tacky when they press together and hair sticks to them in wind. Formulators reduce the tack by thinning the polybutene with lighter emollient esters such as octyldodecanol, ethylhexyl palmitate and caprylic/capric triglyceride, which is what a non-sticky gloss claim usually means in the formula⁴.

Polybutene is a petrochemical, so a gloss that uses it cannot be described as plant-based even when the rest of the formula is plant oil. Lip oils replace it partly or wholly with jojoba, squalane or castor oil, which is why they feel lighter and shine less.

Written and fact-checked by the India Anaïs editorial team. Every number and rule is linked to its source. How the guides are made.