Jennifer Garner, 52, calls this density booster 'the secret to thinning hair'

Jennifer Garner knows a thing or two about beauty. The 52-year-old actress, producer and spokeswoman loves sharing her favorite affordable products with fans — from Neutrogena moisturizers to her go-to foundation to nonbeauty picks like sneakers and cookware. One of the star's recent endorsements is Virtue Flourish Hair Thinning Density Booster Spray, which the A-lister credits with giving her locks a much-needed boost.

In an Instagram Reel made with hairstylist and Virtue Labs Creative Director Adir Abergel, Jennifer Garner called this "the secret to thinning hair — the biggest hair innovation for thinning hair in years and years." Abergel also emphasized that the spray is "drug-free," with Garner adding that "everything is good in here ... you can use it when you're pregnant, you can use it when you're nursing ... I would have killed for it when I was nursing my babies and so much of my hair fell out."

Indeed, Virtue Flourish Density Booster was created as a botanical, natural solution to hair thinning, using a clinical-grade protein and nutrient blend to nourish the scalp. The protein is identical to keratin, which makes up the hair, skin and nails and which may be lacking in thinning hair. The spray also works to thicken and strengthen strands while boosting roots and adding more volume to limp locks. Even more, it's designed to add more elasticity and flexibility to strands, helping prevent more breakage and fallout and returning hair to its luscious former look. The spray is free of sulfates, parabens, phthalates, and synthetic colors and dyes.

Though the Virtue thickening spray is a newer Amazon find, reviewers are already raving about their results after using it.

"Genetically I have very fine and thinning hair, and I had noticed that I was loosing the little I had," confessed a shopper. "I haven't used it for a long time — about three weeks, give or take a day. I have seen some new growth by my temples and also a reduction in hair loss. ... So far my hair is looking better and healthier. Also, I noticed I had very oily hair, and it's less oily now."

"Been using this a little over a month and I have new growth happening," marveled another another reviewer. One skeptic added, "I did not think it was working, but my hair grew about .75" in a month."

"It seems as though it takes a lot for each application," noted a user. "I don't have a lot of hair — my hair is very fine and not thick. I part it about every inch and spray it on the scalp. Perhaps I'm using too much? I'm not sure, but I am surprised at how fast the amount in the bottle is going down."

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The reviews quoted above reflect the most recent versions at the time of publication.