Study Links Long-Term Hair Dye Use to Higher Cancer Risk - Video

That perfect hair color might come with hidden risks. A comprehensive systematic review spanning over 60 years of research warns that frequent, long-term use of hair dyes—especially permanent types—may raise cancer risk in certain groups, urging caution amid a booming $23 billion global market. Published after analyzing 96 studies from 1964 to March 2025 in JAAD International, the findings spotlight potential dangers from chemicals that deeply penetrate hair shafts, calling for more rigorous safety checks.

Hair dyes fall into temporary, semi-permanent, and permanent hair dyes (PHDs), which dominate 80% of sales due to their lasting, natural-looking results. PHDs contain oxidative compounds like m-aminophenols that alter hair structure at the cortex level, unlike gentler non-oxidizing options. With Asia leading sales at over 35% of revenue, widespread use raises questions about long-term health impacts. Researchers conducted a thorough PubMed and MEDLINE search, with three independent reviewers screening articles for relevance to cancer links in adults, children, and maternal exposure.

The review included 96 high-quality studies, two covering both adults and kids, and five examining prenatal dye use. Key patterns emerged: African American women using dyes frequently showed higher estrogen receptor-positive breast cancer risk. Both men and women had elevated bladder cancer odds with heavy PHD exposure. Genetic factors amplified dangers—people with slow acetylator N-acetyltransferase 2 (NAT2) or CYP1A2 variants faced steeper risks, as these impair chemical breakdown. Most concerning, maternal first-trimester use doubled offspring risk of acute lymphoblastic leukemia, worsening with lactation exposure.

Despite consistent trends, limitations persisted: inconsistent study designs, small populations, and confounders like smoking or genetics muddied some results. No definitive causation was proven, but the volume of suggestive evidence warrants attention.

Experts stress moderation for high-risk groups—those with slow-metabolizing genes, frequent users, or during pregnancy—and advocate safer formulations. “While not all dyes are equal, long-term PHD reliance merits pause,” the authors conclude. As the industry grows, this review pushes for better labeling, genetic screening, and prospective trials to protect consumers chasing that flawless shade.

REFERENCE: Greene RK, Maghfour J, Nguyen C, Baker G, Mesinkovska NA. Association between hair dye use and human cancers: A systematic review. JAAD Int. 2025 Oct 25;24:205-233. doi: 10.1016/j.jdin.2025.10.009. PMID: 41399670; PMCID: PMC12702374.