The Sulfate Story
Sulfates like Sodium Lauryl Sulfate and Sodium Laureth Sulfate can be a bit too enthusiastic in their mission to cleanse — and that’s actually an issue, according to Turnbull. “They create a frothy lather and leave our hair squeaky clean, but in the process, they can strip our hair of its crucial natural oils,” Turnbull says. “This often results in dry, brittle hair prone to breakage, potentially contributing to a thinning appearance. This can be particularly detrimental for those with naturally curly or coarser hair types.”
They can also weaken the hair follicles and contribute to hair thinning and shedding, particularly in individuals with sensitive scalps or existing hair concerns, according to Backe.
The Paraben Paradox
Parabens are preservatives commonly used in cosmetic products, including shampoos, to prevent the growth of bacteria and prolong shelf life. “While research is ongoing, some studies suggest that parabens may have hormonal effects, potentially disrupting the natural balance and functioning of the scalp,” Backe says.
Parabens are quite adept at mimicking estrogen, Turnbull explains: “When our bodies are faced with an excess of these pseudo-hormones, it can disrupt our delicate hormonal balance, possibly leading to hair loss. This silent epidemic can affect both women and men.”
Your best option is to opt for paraben-free shampoos, especially if you have concerns about hair thinning and shedding, Backe notes.
The Isopropyl Alcohol Enigma
This fast-drying alcohol finds its way into many hair products, according to Turnball. “Despite its speedy evaporation benefits, it's a bit of a double-edged sword when it comes to hair health,” she says. “Its penchant for removing moisture can leave hair dry and frizzy, more prone to breakage. Worse, it can irritate the scalp and cause a reduction in oil production, which can lead to brittle, lifeless thin locks.”
One more to avoid: Formaldehyde-releasing agents
Why stop at just three ingredients when there’s a fourth to avoid: formaldehyde-releasing agents. “Some shampoos may contain formaldehyde-releasing agents, such as DMDM hydantoin, diazolidinyl urea, and imidazolidinyl urea,” Backe says. “These chemicals are used as preservatives to prevent microbial growth. However, formaldehyde and its releasing agents can be irritating and potentially damaging to the scalp and hair. Prolonged exposure may contribute to hair loss and thinning.”
Backe says it's important to note that individual responses to ingredients can vary, and some people may not experience any negative effects from these ingredients. “However, if you are concerned about thinning hair and shedding, it may be beneficial to choose shampoos that are labeled sulfate-free, paraben-free, and without formaldehyde-releasing agents,” Backe says. “Additionally, consulting with a dermatologist or trichologist can provide personalized guidance based on your specific hair and scalp condition.”