With proven ingredients like biotin, caffeine and niacinamide, this color-safe pair aims to promote stronger, thicker locks.

The Dr. Groot Scalp Revitalizing Solution is a hair growth shampoo from a popular Korean brand. Shoppers with thinning hair say it thickens hair and fills in sparse areas. Buy it at Amazon on sale for $21.

Hair growth is a complex biological process that involves the hair follicles, the cells within the scalp, and various nutrients. It is a natural cycle that all humans experience, but it can vary in speed,

“Shampoo with rosemary is helpful for anyone desiring to reduce shedding or anyone who desires to have hair to be thicker and fuller,” says Candace Spann, MD, a dermatologist, hair loss specialist, and the founder of ReTress. That being said, it's not a miracle ingredient.

Shampoo isn’t just for cleaning hair—the right formula can be your first step to thickening and filling out thinning hair and stopping breakage. From postpartum or stress-induced hair loss to natural hair thinning with age,