Many shampoos and conditioners now claim to reduce hair loss, boost growth, and even combat greying, but a leading trichologist advises caution regarding these claims, particularly for budget-friendly options.
While medications like minoxidil and finasteride are scientifically proven to stimulate hair growth, most cosmetic products aim to improve the appearance of hair thickness. According to trichologist Eva Proudman, founder of UK Hair Consultants, ingredients such as peptides, niacinamide (vitamin B3), biotin (vitamin B7), and rosemary oil can make hair strands appear fuller.
Peptides, which are building blocks of keratin, can bind to the hair shaft, increasing its diameter and creating a fuller look. However, Proudman emphasizes that this effect does not penetrate the hair follicles or stimulate new growth. "Unfortunately, the rate of hair growth is inherited and you'll have the same number of follicles that you're born with throughout your life," she stated.
Products containing collagen and niacinamide are also noted for their ability to thicken individual hair strands. Ingredients like rosemary oil, tea tree, ginger, and menthol may help soothe the scalp and potentially reduce inflammation that could hinder growth. Proudman suggests that leave-on treatments, such as serums, are more likely to yield noticeable results than shampoos due to their longer contact time with the scalp. She noted that products like the L'Oréal Professionnel Absolut Repair Molecular Leave-In Mask or the OGX ProGrowth + Peptide Clarifying Shampoo can be as effective in boosting hair strength and fullness as more expensive options.
Claims regarding caffeine's ability to boost hair growth are largely unsubstantiated, according to Proudman. While some laboratory studies suggest it can increase blood flow to follicles and block hormones that limit growth, she stated, "There's little proof you'd get the same effect on a human scalp, especially within a shampoo that's quickly rinsed off." She characterized such claims as "more marketing than science."
Many of the advertised benefits, such as "20 per cent fuller hair," are often based on customer surveys rather than rigorous scientific studies. Proudman pointed out that studies like one for L'Oréal Elvive Growth Booster, tested on only 87 people, lack the robust methodology required for strong scientific evidence, such as double-blind random placebo studies.
Regarding claims about reversing grey hair, experts state that greying is primarily due to genetics, stress, or environmental factors. While some products may use colorants or optical brighteners to alter the appearance of grey hair, they do not reverse the pigment loss. The Cosmetic, Toiletry and Perfumery Association confirms that the only proven method to change grey hair color is through dyeing.
In summary, while certain ingredients can improve the perceived thickness and appearance of hair, most shampoos do not promote actual hair growth. Proven hair loss treatments involve medication, and cosmetic products' effectiveness is often overstated in marketing. For noticeable results, leave-in treatments with ingredients like peptides and niacinamide are generally more effective than rinse-off shampoos. High prices do not necessarily correlate with better results, with affordable options often containing similar beneficial ingredients.
