Encyclopedia
Every molecule that touches your hair
From proven medicines to kitchen-cupboard oils, with the studies behind each one.
15 entries
A
-
surfactant
Ammonium laureth sulfate
The ammonium-salt version of SLES, an ethoxylated sulfate cleanser that is gentler than lauryl sulfates and can carry a trace by-product called 1,4-dioxane.
-
surfactant
Ammonium lauryl sulfate
The ammonium-salt twin of SLS, a strong cleanser with essentially the same cleaning power and irritation profile.
B
-
other
Bentonite
A swelling clay used in clay masks and some matte styling products as an absorbent and thickener; "bentonite washes" are untested for hair.
K
-
other
Kaolin
A soft white clay used in matte clays, pastes and dry shampoos to soak up oil and give a dry, textured finish.
-
anti dandruff
Ketoconazole
An antifungal shampoo ingredient that is among the best-proven treatments for dandruff and, with much weaker evidence, a possible add-on for pattern hair loss.
N
-
other
Niacinamide
Niacinamide is a safe, cheap vitamin B3 form found in many hair serums, but no trial shows it grows hair on its own.
O
-
antiandrogen
Oral contraceptives and antiandrogenic progestins
Some birth-control pills lower androgens or block their receptor, but almost no trial shows that any pill regrows scalp hair.
P
-
anti dandruff
Piroctone olamine
A gentle anti-dandruff ingredient common in European shampoos, with trial results roughly equal to zinc pyrithione but mostly from manufacturers.
S
-
anti dandruff
Salicylic acid
A scale-loosening ingredient that helps thick flakes and scalp psoriasis plaques and works best paired with an antifungal.
-
anti dandruff
Selenium sulfide
An old, inexpensive anti-dandruff active that new trials suggest works about as well as ketoconazole and has been tested across all curl types.
-
other
Silica silylate
Water-repelling fumed silica used in texturising powders, sprays and pastes for grip, a dry feel and oil absorption.
-
surfactant
Sodium C14-16 olefin sulfonate
A sulfonate-based cleanser common in sulfate-free shampoos that is still a strong degreaser, so sulfate-free does not always mean gentle.
-
surfactant
Sodium laureth sulfate
The workhorse cleanser of mainstream shampoos, SLS with a short ethylene-oxide chain added, which keeps most of the cleaning and foam and is gentler, with a trace by-product called 1,4-dioxane.
-
surfactant
Sodium lauroyl sarcosinate
An amino-acid-derived cleanser with good foam and cleaning power that is marketed as mild, though its mildness sits in the middle.
-
surfactant
Sodium lauryl sulfate
A cheap, strong cleanser and foamer that removes oil very well but is the most irritating common shampoo surfactant, so dermatologists use it as their standard test irritant.