We may earn a commission through links on our site. Why Trust Us? These days, thickening shampoos are a dime a dozen, most of which contain ingredients like biotin, saw palmetto, caffeine and a ...

The hair thickening shampoo we’re talking about is John Frieda’s ULTRAfiller+ Thickening Shampoo. Per the brand, it was made to help you achieve 200% thicker and fuller hair “instantly.” ...

We’ve spotlighted R+Co’s Dallas Biotin Thickening Shampoo more than once over the years, and for a good reason—it’s tough to beat as an all-around thickening shampoo for thinning hair.