The Rootist BioBrew Fermented Strengthening Serum is truly a game-changer in the world of hair care. From its innovative concept to its great scent and multitude of benefits, this serum stands out as a must-have for anyone looking to elevate their hair care routine.The use of fermentation in hair care products is relatively novel, and The Rootist has embraced this technique which feels amazing on my hair! I'm such a big fan of this serum being a leave-in formula, which is a godsend for busy individuals or anyone looking to streamline their hair care routine. Rather than rinsing out after a few minutes, you simply apply it to damp hair and go about your day. This convenience factor is great. I also love the amazing benefits including combatting frizz, and providing much-needed heat protection (I like having multiple products in my routine that do this since I often use styling tools). It also added a bit of shine to my hair and felt like it would prevent from breakage. It's an easy to use product with great results I've seen so far! **This review was collected as part of a promotion.