research The Shampoo pH Can Affect the Hair: Myth or Reality? 51 citations, January 2014 in “International journal of trichology” Shampoo pH can affect hair health, with alkaline shampoos potentially causing damage and acidic shampoos reducing frizz.
research Effect of Surfactant Type on the Dyeability and Color Resistance of Semi-Permanent Basic Hair Dye January 2023 in “Fashion and textiles” Cationic and nonionic surfactants provide better color intensity and resistance for semi-permanent hair dye than anionic surfactants.
community DIY Shed treatment & thick regrowth, Vitamin C shampoo in Treatment 8 upvotes 2 years ago DIY hair loss treatment with vitamin C in shampoo reduced shedding and promoted regrowth, benefiting both the original poster and their wife.