Sulfates
Sulfates are commonly found in shampoos since they can strip the hair of dirt and oils. Unfortunately, sometimes the sulfates strip down your hair too much, leaving it weakened.
Dr. Joshua Zeichner, Director of Cosmetic and Clinical Research at the Department of Dermatology at Mount Sinai Hospital, tells SheFinds, "While sulfate-based surfactants can effectively clean the hair, they can cause significant dryness and irritation of the scalp and lead to hair brittleness."
Alcohol
Alcohol is another ingredient you want to keep an eye on, but it's important to remember that not all alcohols are the same. Likewise, their effect on your hair will vary. According to WebMD, if alcohols have "prop" in their name, you should steer clear. These alcohols will likely dry your hair out, making it more susceptible to breakage and other types of damage.
On the other hand, fatty alcohols (like cetearyl alcohol, cetyl alcohol, and stearyl alcohol) can actually help moisturize dry hair.
Botanical Oils
Shab Reslan, scalp and hair loss expert, trichologist, and HairClub's artistic educator and master stylist, says that these types of oils can lead to problems for your hair.
"Many plant-based hair product brands contain high concentrations of botanical oils," she tells SheFinds. "These are intrinsically irritating ingredients, and, if combined with alcohol, the penetration is enhanced on the scalp, which may increase irritation in sensitive individuals." An irritated scalp can mean trouble for your hair growth and health.
Synthetic Fragrance
When it comes to any product you are putting on your body, it's a good idea to avoid synthetic fragrances. According to Nutrafol, products with fragrance "can contain thousands of hidden chemicals." These chemicals can lead to scalp irritation, which can contribute to hair loss.