The active ingredients on an eye drop label

Active ingredients is the first section of every Drug Facts panel. It names the ingredients that do the drug’s job, gives each one’s strength, and states its purpose in a word or two.

Quell’s three

• Glycerol (1.0%): lubricant
• Polysorbate 80 (1.0%): lubricant
• Light Mineral Oil (0.5%): emollient

Reading the purpose

“Lubricant” and “emollient” are the label’s own summaries. Lubricants are what make a drop a lubricating eye drop. An emollient is an oily ingredient that softens and coats. Quell has two of the first and one of the second, and the emollient is the oil-based one, which fits a formula designed around the tear film’s oil layer.

Reading the strength

The percentage beside each name is its concentration in the solution. What the percentages mean explains how to read them, and why they are hard to compare across brands.

Active versus inactive

Everything else in the bottle is listed further down, under Inactive ingredients. Inactive doesn’t mean unimportant: Quell’s emu oil is an inactive ingredient, and it is the reason for the label’s allergy caution.

Each one in more detail

Glycerol, polysorbate 80 and light mineral oil each have a guide of their own.