Shoppers Say This $9 Hair Growth Shampoo Thickens Hair In As Fast As Two Weeks

As much as you wish every day could be a good hair day, sometimes your mane just falls flat — literally. Especially if you deal with thinning hair, styling your tresses can be an inevitably frustrating experience. Hair loss is a common issue, and can be triggered by a number of factors, including stress, medications, and genetics; but luckily, you can fight back with the right products. Enter: Viviscal's Densifying Shampoo for Gorgeous Growth (Buy It, $9, amazon.com).

With more than 10,600 five-star ratings, this shampoo for thinning hair is a favorite of Amazon shoppers, who call it a "game changer." The product contains a special complex made with biotin, zinc, and keratin — three ingredients that are intended to help fortify hair and encourage growth. Keratin, a protein, has been shown to strengthen hair, and zinc can potentially be beneficial in reducing hair loss.

Biotin has been shown to improve hair growth, Howard Sobel, M.D., a cosmetic dermatologic surgeon based in New York, and director of Sobel Skin, previously told Shape. The catch? These studies have only been conducted in people who are already deficient in biotin, and they focus on ingested biotin not topical. Still, that doesn't mean biotin shampoos don't have the potential to aid in hair growth, and Dr. Sobel agrees it won't hurt your hair to try them. (

And according to Amazon reviewers, the results speak for themselves — many shoppers have reported positive changes in their strands since they started to use Viviscal's hair growth shampoo. "I have natural Black hair," wrote one five-star reviewer. "After two weeks of using this product my hair shedding decreased significantly. My hair feels thicker. I have no doubt that my thinning crown area will thicken as well."

Buy It: Viviscal Densifying Shampoo for Gorgeous Growth, $9 (was $10), amazon.com

"I've always had thin hair [and] struggled with hair growth because of medicine I have to take, but after using this for about two weeks or so, the hair grew in much thicker than ever before," another customer added. "My hair also has always broken easily, but the strands are so much stronger [now], which obviously keeps the hair on your head. [I don't know] if it actually sparks accelerated hair growth, but it definitely thickens it and prevents breakage, which fosters length."

Others say that the shampoo makes their hair soft and shiny — but not greasy — and it doesn't fade color-treated hair, either. Perhaps best of all is the price: Viviscal's shampoo for thinning hair costs just $9 a bottle, and shoppers say it's "worth buying." If you're dreaming of thicker, fuller hair, this product may just lead to even more good hair days down the road.