Formulation
you don't need a chemistry degree to evaluate a shampoo. you need 30 seconds and these three checks.
check one: look at the first five ingredients.
ingredient lists are ordered by concentration, highest to lowest. the first ingredient is almost always water. the next four ingredients make up the bulk of the active formula — roughly 70-85% of what's in the bottle after water. these are the ingredients that determine how the shampoo actually performs. everything listed after the first five is present at progressively lower concentrations.
what you want to see in positions 2-5: gentle surfactants. names like sodium cocoyl isethionate, cocamidopropyl betaine, decyl glucoside, sodium lauroyl methyl isethionate. these are mild, effective cleansers that won't strip your scalp.
what you don't want to see in positions 2-5: sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES), ammonium lauryl sulfate, or sodium c14-16 olefin sulfonate. these are aggressive surfactants that strip natural oils. if any of these are in the top five, the shampoo is built on a harsh base, regardless of what else is in the formula.
check two: find the 'hero ingredient' and note its position.
every shampoo has a hero ingredient on the front of the bottle — argan oil, keratin, biotin, tea tree, whatever the brand is leading with. find that ingredient in the list on the back. how far down is it?
if it's in the top ten, it's probably present at a meaningful concentration. if it's in the middle of the list (position 12-18 out of 25), it's present but possibly at a low level. if it's below fragrance, sodium chloride, or preservatives like methylisothiazolinone, it's almost certainly below 1% — essentially a marketing dose, added for the label rather than for your hair.
this doesn't automatically mean the product is bad. some ingredients are effective at very low concentrations. but it's worth knowing whether the ingredient that sold you on the product is a significant part of the formula or a token presence.
check three: look for these three filler ingredients.
sodium chloride: table salt. used as a cheap thickener. no benefit for your hair. can be drying. if it's in the top ten, a significant percentage of what you're paying for is salt water.
dimethicone (or any ingredient ending in -cone): silicone. coats hair to simulate smoothness. creates buildup over time. not harmful in a single-use sense, but creates the coating-dependency cycle described in our article about silicones.
cocamide DEA or cocamide MEA: foam boosters. they don't clean anything — they just make the lather bigger and more impressive. they're added because consumers associate big foam with effective cleaning, even though the two aren't related.
none of these ingredients are dangerous. they're legal, they're widely used, and plenty of people use products containing them without any problems. but they're indicators of a
formula that prioritises cheap production and consumer perception over actual hair and scalp health.
that's it. three checks. thirty seconds. look at the first five ingredients, find the hero ingredient's position, and check for fillers. you now know more about your shampoo than 95% of the people who buy it.
the front of the bottle is marketing. the back is the product. read the back.
