37 products on Amazon’s “famous” list for your thirties

K18 is a small company specializing in hair products.

To use, wash your hair with shampoo and no conditioner. Towel dry your hair, apply the hair mask and leave it on for four minutes. Then style as usual without rinsing.

This is what BuzzFeeder Melanie Aman says about it: “I bleach my dark brown-black Asian hair blonde every 6-8 weeks, so when I first heard some stylists at my salon raving about K18, I was immediately intrigued. I was speechless at how much softer my hair was. Seriously. I spent the entire day touching my hair and even my boyfriend thought my mane was noticeably silkier. Olaplex was my favorite before I tried K18, and I still stand behind that product, but I really love that K18 is a leave-in treatment and not a shower mask. Leaving Olaplex on for 10 minutes felt like an eternity, especially if I didn’t take an all-around shower (you know, the ones where you exfoliate and shave). With K18, you leave it in your hair for four minutes after you shower to activate it, and then you can style your hair (or just let it air dry, like I do). I found that my hair is the softest next day, so don’t be discouraged if your hair looks or feels the same on the day of application.”

Promising review: “My hairdresser recommended this product for my hair and it was far superior to all other products I have used. It’s expensive and I have long hair so it’s twice as expensive but it’s worth it. As I got older my hair got really frizzy and dry, but this product changed everything. It made my hair more manageable, silky, soft, voluminous and frizz-free.. I can’t say enough good things about K18.” —Dawne

Get it on Amazon for $29.