1. Silicones
Silicones in shampoo and conditioner aim to reduce frizz and create shinier locks. They can do a great deal to temporarily enhance the look of your strands, but the concern is that they may do long-term damage to your hair and scalp. Silicones can create buildup on your scalp that clogs hair follicles and keeps them from growing hair efficiently. They can also coat strands in a way that prohibits hair from being hydrated, which can lead to breakage over time. In addition to causing potential hair shedding, this ingredient is often linked to scalp itchiness and dandruff.
2. Synthetic Fragrance
Some shampoos smell heavenly, but if their scent is derived from synthetic fragrance, your hair can suffer. Fragrance can cause scalp irritation, which can lead to dandruff, itching, and fallout. It can make your hair dryer and contribute to frizz, result in an imbalance of oil production on your scalp, and even cause rashes if you are highly sensitive to scent.
3. Sulfates
Sulfates have their benefits. Namely, they create the sudsy conditions that can really help get your scalp and hair clean. But, in most cases, you can use a gentler shampoo that is free of sulfates and it will do just as great a job. Sulfates can be drying to your scalp and hair, and can cause irritation and dandruff. When dandruff builds on and around hair follicles they become blocked, which affects hair growth.
4. Phthalates
Phthalates are chemicals found in shampoo that act as stabilizers. In addition to some potential health concerns linked to them, including that they are endocrine-disrupting chemicals, they can irritate your scalp and cause redness, itching, and dandruff. They can disrupt the scalp’s natural oil balance and weaken hair follicles, which leads to hair shedding and breakage. To avoid the damage they can do, look “for shampoos that are labeled phthalate-free" or "free from harmful chemicals.”