Need a beauty expert for a hair care story I'm writing a story on 2 Hair Care Ingredients To Stop Using Because They Cause Fallout & Weaken Hair, According To Derms and need an expert source. If interested, please answer the following questions: -what are 2 hair care ingredients to avoid for hair loss? -how do these ingredients cause fallout and weaken hair? -in what products are these ingredients mostly found in and what should we use instead?

There are two ingredients I caution patients about for "hair loss" that is really breakage are harsh sulfates and glyoxylic acid based straighteners. In a 2025 ex vivo hair study, increasing sodium lauryl sulfate or sodium laureth sulfate from 5% to 30% for a 10 minute exposure raised protein loss threefold for SLS and sixfold for SLES, and a 5degC temperature increase nearly doubled protein loss. I see sulfates mainly in high foam shampoos and clarifying washes. Switch to sulfate free cleansers with milder surfactants, then condition the ends. For smoothing, glyoxylic acid derivatives show up in many "formaldehyde free" keratin treatments. A 2025 straightening study used a pH 1 formula plus flat ironing at 180degC and documented lipid and protein changes that weaken the shaft.

Shamsa Kanwal, M.D., is a board-certified Dermatologist with over 10 years of clinical experience. She currently practices as a Consultant Dermatologist at https://www.myhsteam.com/ Profile link: https://www.myhsteam.com/writers/6841af58b9dc999e3d0d99e7 My take on your question is given below: Q: what are 2 hair care ingredients to avoid for hair loss? A: 2 hair care ingredients to avoid are formaldehyde or methylene glycol in some keratin straightening treatments, and p-phenylenediamine (PPD) in many permanent hair dyes. Neither is the most common cause of true hair loss, but both can trigger scalp inflammation or hair shaft damage that looks like fallout and thinning. Q: how do these ingredients cause fallout and weaken hair? A: Formaldehyde based smoothing treatments rely on chemical processing plus high heat, which can make the hair shaft brittle so it snaps, especially at the mid lengths and ends. PPD can cause allergic contact dermatitis on the scalp, leading to itching, burning, scaling, and scratching, which can increase shedding and breakage and sometimes cause noticeable thinning after a bad reaction. Q: in what products are these ingredients mostly found in and what should we use instead? A: Formaldehyde or methylene glycol shows up in some salon keratin and Brazilian blowout style treatments, and the safer swap is choosing a clearly formaldehyde-free smoothing service, limiting flat iron heat, and using a heat protectant plus a conditioning or bond repair mask weekly. PPD is mostly in permanent and dark box dyes and many salon dyes, and alternatives include PPD-free color, semi-permanent dyes, highlights or balayage that avoid the scalp, and patch testing 48 hours before coloring. If someone is shedding for more than 8 to 12 weeks, has scalp pain or scaling, or sees bald patches, I would recommend a dermatology evaluation because the cause is often hormonal, nutritional, autoimmune, or stress related rather than a single ingredient.