How to read a product label
Ingredients are listed in descending order of concentration. Once you know how to read a label, you can cut through any product's marketing and see exactly what you are putting on your hair.
Every ingredient list on a hair product follows the same international naming system: INCI (International Nomenclature of Cosmetic Ingredients). Ingredients appear in descending order of concentration, so the first five are doing the most work.
Water (Aqua) is usually first in rinse-off products. The next few ingredients after water typically form the backbone of the formula. In a conditioner, you might see Cetyl Alcohol or Behentrimonium Chloride, which are emulsifiers and conditioning agents, not the harmful alcohols you might associate with dryness.
Ingredients below 1% concentration can appear in any order. Fragrance, preservatives, and actives are often here. This also means a product can legally claim to contain an ingredient while using a negligible amount.
When in doubt: look at where an ingredient sits in the list. If it is in the second half, its effect on your hair is likely minimal.