"Routine" is a high-end shampoo brand that claims their formulation is safe, simple, and effective. Their products are very expensive, at a price point of around $25 per bottle. The shampoo and conditioner contain a large number of botanical ingredients shown to be effective for improving hair quality and hair appearance. However, it also contains Phenoxyethanol, a synthetic preservative shown to be toxic to human cells in a 2020 clinical trial. This was a test tube study, which is a weaker standard of evidence than a trial with human participants. There are mixed reviews about the product. Some users have reported positive experiences, noting improvements in hair thickness, damage prevention, and even hair growth after using the product. Others have reported less satisfactory experiences. Therefore, the legitimacy of "Routine" may depend on individual experiences and expectations. It's always recommended to do thorough research and consider personal hair care needs before trying a new product.