Contents

A thick, shiny, usually sheer lip product. Gloss is sold on shine, and shine is a physical property of the surface rather than an ingredient — a smooth, high-refractive-index film reflects light specularly instead of scattering it, and that is the whole technology.

What makes it shiny

Ingredient Role Note
Polybutene / hydrogenated polyisobutene The backbone of modern gloss High refractive index, viscous, non-drying — this is what produces the shine and the stickiness together
Castor oil Traditional gloss base Good pigment wetting, high gloss, distinct taste
Esters and light oils Slip and spread Isopropyl myristate, triglycerides
Silica or clays Suspend pigment, control flow Keeps sparkle in place
Pigment / pearl Colour, if any Iron oxides, certified lakes, mica
Flavour and sweetener The reason people buy a particular one Aroma, saccharin, sucralose

Stickiness and shine come from the same molecule. Polybutene's viscosity is what holds the film smooth and thick enough to reflect; reduce it for comfort and the shine drops. Non-sticky glosses use lighter esters and silicones and are correspondingly less glossy.

Formats

Wand in a tube is standard. Squeeze tubes are more hygienic. Gloss balms and tinted oils blur into Lip Balm and Lip Oil at one end, and into Lipstick at the other where pigment load is high enough to be opaque.

What gloss does and does not do

  • It reads as fullness. A shiny convex surface catches a highlight along the centre, and the eye reads that as volume. This is why gloss over lipstick at the centre of the lower lip is a standard trick.
  • It does not moisturise, particularly. Most gloss bases are occlusive rather than hydrating — they seal, they do not add water. A gloss over dry lips seals in dryness. See Lip Mask.
  • It wears off fast. Twenty minutes to an hour, and it goes with the first drink.
  • It catches hair. This is not a formulation flaw, it is the viscosity.
  • Flavour is the leading irritant. Cinnamates, mint and citrus flavourings are common causes of lip contact dermatitis, and the tingling in a "plumping" gloss is deliberate irritation — see Lip Plumper.

Where it sits in the rules

Cosmetic in the US — FDA primary category (08), makeup preparations (not eye) — under the strictest colour rules of any cosmetic, because lip products are partly ingested:

  • Colour additives must be approved by FDA specifically for use in cosmetic lip products, and certified colours must come from FDA-certified batches. Chromium oxide greens and ultramarines, permitted for eyes and external use, are not permitted on lips.
  • Carmine (CI 75470) must be declared by name.
  • FDA's December 2022 final guidance recommends a maximum of 10 ppm lead in cosmetic lip products and externally applied cosmetics.

Glitter in a gloss must be cosmetic-grade polyester or plant-derived; craft glitter is cut plastic and does not belong near a mouth or an eye.

In the EU, colorants come from the Annex IV closed positive list — 153 entries.

Shelf life

Twelve months after opening. The dominant format returns a used wand to a warm reservoir every application, which is the contamination route, and gloss is applied more often through a day than any other lip product.

Do not share a gloss, and discard any tube used during a cold sore outbreak. A squeeze tube or a decanted amount on a brush is the hygienic way to use one on someone else.