10 Top-Rated Hair Serums Overzealous Amazon Reviewers Can't Get Enough Of

Rating: 4.2 stars, 2,235 reviews 

What people are saying: "I love this stuff! This is part of my hair routine every time I style my hair. I have thick, frizzy hair that tends to soak up styling products. With this product, a little bit goes a long way. The first bottle lasted me five months. It also builds well, without making my hair greasy, which is important because I can only wash my hair every four days, otherwise it dries out."

Rating: 4.4 stars, 251 reviews

What people are saying: "Terrific product. I squirt a few drops in my palms, then I brush fingers and hands right through my short, but full crop of graying hair. It makes these tresses look ever so shiny and silky while keeping it all in place. [I] don't even need to use hairspray. I especially like the fact that it's not greasy, nor gummy, nor does it have an odor. It just has a pleasant and unassuming scent. Most of all, this product enhances the natural wave and light curl that I still have. For me, it's best used right after a shampoo and a towel dry."

Rating: 4.3 stars, 302 reviews

What people are saying: "This stuff is GREAT. Works on my normally flyaway, wavy, tangled hair, making it straighter (with the help of a flat iron). I've actually grown a decent ponytail that I never could have before. I should mention I'm a guy, and I could have really used this stuff back when I was younger, playing in rock bands. I now have a ponytail for the first time in my life."

Rating: 4.7 stars, 437 reviews

What people are saying: "I have naturally curly hair and it has been on ongoing battle to keep the curls in my preferred curl pattern which is large ringlets without looking dry or, to the other extreme, oily. Since using Revlon Uniq One, my hair looks healthier and keeps the pretty curl pattern much easier and feels soft. I will be using this as long as it's available."

Rating: 4.2 stars, 807 reviews

What people are saying: "I wish I had known about this product years ago. My hair has always been on the thick side, but dry and brittle (yes, I color it frequently. I like to be blonde, what can I say?). Previously, it wouldn't grow past my shoulder blades—it kept breaking and I would get split ends and have to trim it constantly. Now, however, even my stylist comments on how long, silky and strong my hair is becoming. It isn't an overnight result, although the smoothness did happen overnight, but the length is definitely extending and the strength of my hair is unbelievable. I'm still golden blonde, still flat-ironing and curling and damaging my hair as we all do, but it looks shiny and gorgeous and healthy."

Rating: 4.2 stars, 489 reviews

What people are saying: "I have long wavy/frizzy hair that is dry at the ends, and oily at the scalp. This is the only 'fancy' hair product I use, and it's ALL I need to use to make my hair look gorgeous. It's also the only hair product I have purchased over and over again for several years, now. Why? Because it works. It doesn't matter what shampoo or conditioner I use, when I apply this after I wash my hair, it's perfect every time."

Rating: 4.6 stars, 369 reviews

What people are saying: "I have very dark brown, long, coarse hair and I live in a very humid climate. As a result, my hair would inevitably succumb to the frizzies, no matter what product I used. While this product can make the top of my hair a bit greasy looking, if I'm not careful in how I apply it, it does an excellent job of keeping the frizzies at bay. I expect that I will eventually figure out just the right amount of product to use and how to best apply it to avoid greasy roots. I use more than one pump, because of the length of my hair, but if you have fine hair or not very long hair, you should be able to get the desired result with one pump or less."

Rating: 4.7 stars, 47 reviews

What people are saying: "I’ve just started using this product and it is amazing. I have highlighted hair and after my normal products my hair felt like straw. Now after using their dandruff shampoo, cream rinse, and serum for fly sways my hair feels so silky."

Rating: 3.8 stars, 434 reviews

What people are saying: "The ends of my hair tend to get super dry in the Summer no matter how much I try to protect it from the Sun and get the ends trimmed every six weeks or so. This product did exceed my expectations. It really has kept my ends from getting frizzy and really leaves a nice, vibrant, healthy shine. I think I can cut back on the trims every six weeks and get them done every eight weeks instead. A little is all you need or you may find this to be heavy and greasy. I had to experiment with this till I figured out how much I really needed which was about a half of a dime size for my hair."

Rating: 3.5 stars, 50 reviews

What people are saying: "This stuff is AWESOME. Been using it for years, my hair is shoulder length, wavy (but I iron it straight) and lightened blond. This gel, and you only need a little, makes my hair positively sparkle, and not in a gauche way, it looks very natural. Leaves hair soft and style-able, on the day you wash it and beyond. I couldn't recommend it more highly, it's a great hair product."