Us Weekly has affiliate partnerships. We receive compensation when you click on a link and make a purchase. Learn more! There’s a funny thing that happens as we get older: our hair doesn’t seem to pick just one problem. The grays start multiplying, your ponytail doesn’t feel quite as thick as it used to and suddenly your bathroom cabinet is overflowing with root touch-up sprays, volumizing products and hair-growth treatments. Luckily, there’s a breakthrough new serum that does the work of all three, making your hair routine a whole lot simpler. Meet K18’s FutureIQ Biomimetic Hair Longevity Serum, the brand’s newest launch that’s taking aim…
