Bleaching hair twice makes it very dry and weak.
2 citations
,
March 1942 in “JAMA” 4 citations
,
August 2016 in “PubMed” Repeated dyeing and shampooing cause hair color loss and damage.
1 citations
,
January 2023 in “Indian Journal of Animal Research” A new method effectively stains hair samples for study without losing hair sections.
May 2026 in “Zenodo (CERN European Organization for Nuclear Research)” The herbal hair dye with Barleria prionitis is a safe, effective, and natural alternative to chemical dyes.
79 citations
,
January 1975 in “Food and Cosmetics Toxicology” The hair dye formulations tested did not cause long-term toxicity or cancer in mice.
1 citations
,
February 1989 in “PubMed” Electrophoresis can effectively analyze hair proteins for forensic use, even after cosmetic treatments and up to 2 years of weathering.
5 citations
,
January 2011 in “International Journal of Cosmetic Science” 1,2,3,4-tetrahydroquinoline compounds are great for stable, pure blue hair dye.
18 citations
,
July 2015 in “Journal of cosmetic dermatology” Straightening and coloring hair, especially with sodium hydroxide, greatly increases protein loss.
December 2025 in “International Journal of Research in Dermatology” The Ayurvedic treatment safely and effectively restores natural hair color by increasing black hair and reducing grey hair.
January 1990 in “Springer eBooks” Some chemicals can permanently or temporarily remove color from skin and hair, which can be distressing and is not well-regulated in cosmetics.
4 citations
,
April 1999 in “Dermatologic Clinics” Long-pulsed ruby lasers effectively reduce hair for up to 2 years with minimal pain.
1 citations
,
January 2010 in “LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas)” Conditioners improved hair protein retention and combing ease, with some providing thermal protection.
June 2025 in “Clinical and Experimental Dermatology” A 76-year-old man's grey hair turned back to its original color after radiotherapy.
13 citations
,
March 2010 in “International Journal of Cosmetic Science” Hair coloring increases copper and calcium uptake, damaging hair and reducing shine.
3 citations
,
June 2023 in “ACS sustainable chemistry & engineering” The study found a green method for strengthening hair works on all hair colors and is eco-friendly.
1 citations
,
June 2023 in “Skin Research and Technology” Hair-coating shampoos dye better initially, but hair-oxidation shampoos keep color longer and may damage hair more.
450 citations
,
January 2005 in “The journal of investigative dermatology/Journal of investigative dermatology” Hair color is determined by melanin produced and transferred in hair follicles.
7 citations
,
January 2013 in “Journal of Cosmetics, Dermatological Sciences and Applications” Argan oil and cupuassu butter can protect hair after dyeing.
June 2026 in “Zenodo (CERN European Organization for Nuclear Research)” Henna is a safer, natural hair dye but needs more research and standardization.
November 2024 in “Majalah Farmasetika” The natural hair dye gel with 12% Eleutherine bulbosa extract effectively colors bleached hair dark brown and is stable and non-irritating.
4 citations
,
May 2014 in “PubMed” Monoethanolamine-based hair colorants can cause more damage to hair than ammonia-based ones.
20 citations
,
July 1988 in “Clinics in dermatology” Thioglycolate lotions are the most popular method for permanent waving and hair straightening.
7 citations
,
January 1995 Silicone pretreatment protects hair from damage and reduces color fading without interfering with bleaching or dyeing.
35 citations
,
January 1981
June 2026 in “Zenodo (CERN European Organization for Nuclear Research)” Herbal hair dye with Bhringraj is effective, safe, and eco-friendly.
8 citations
,
May 2003 in “Clinical and Experimental Dermatology” A 14-year-old girl's black hair showed unique color changes, suggesting early greying.
June 2026 in “Zenodo (CERN European Organization for Nuclear Research)” Herbal hair dye with Bhringraj is effective, safe, and eco-friendly.
11 citations
,
August 1986 in “Archives of Dermatology” Vitamin B12 deficiency can cause skin and hair color changes, which can be reversed with treatment.
August 2021 in “Han'gug miyong haghoeji/Journal of the Korean society of cosmetology” Using natural polyphenol cross-linkers like tannic acid and green tea extract in perm treatments improves curling and protects hair.