3 Editors Try The Ordinary Hair Serum. Here Are Their Honest Takes

consistency is key

PureWow editors select every item that appears on this page, and the company may earn compensation through affiliate links within the story. All prices are accurate upon date of publish. You can learn more about the affiliate process here.

the ordinary hair serum review
Paula Boudes/PureWow/Retailers/Marissa Wu/Candace Davison/Katherine Gillen

As someone with fine, flat hair, I’ve always been a bit self-conscious about my lack of it. Especially since we’re surrounded by advertisements featuring models with full, gleaming locks. I’m working on loving—and working with—what I’ve got, but I’m also curious about hair serums that bill themselves as the fix to all my problems. So, when I read that The Ordinary’s Multi-Peptide Serum for hair density was a top trending product this year, I was intrigued. Would it actually live up to its claims? I decided to find out and tapped two fellow editors with similar hair types to test it with me. Here are the results.

Want more beauty tips sent right to your inbox? Subscribe here.

What’s In The Ordinary Multi-Peptide Serum for Hair Density?

The serum’s key ingredients are REDENSYL™, Procapil™, CAPIXYL™, BAICAPIL™, AnaGain™ and caffeine. The first four are all trademarked ingredients that are commonly found in hair growth products to stimulate hair growth and reduce hair loss. Notably, Capixyl consists of red clover extract and biomimetic peptides, which, as hairstylist Devin Graciano previously explained to me, is a trendy ingredient this year. Regarding caffeine, a 2012 study reported that it yielded positive results in alopecia patients, as the caffeine worked to prevent hair loss and stimulate growth.

How to Use the Serum

The instructions are simple, but as one of PureWow’s editors notes below, it may require some time management. You must apply a minimum of three drops to clean, dry hair before massaging them into your scalp. The Ordinary recommends using the serum daily, preferably at night.

How I Tested The Ordinary Multi-Peptide Serum for Hair Density

According to the National Library of Medicine, hair grows an average of 0.35 millimeters per day or 0.41 inches per month (30 days). Thus, it was important to test the hair peptide serum for at least eight weeks to gauge if it yielded any visible results. I enlisted PureWow’s Vice President of Editorial, Candace Davison, and Senior Food Editor Katherine Gillen, to test the product with me. We all have fine hair in varying degrees of density and were hoping that the serum would deliver on its promise of improving thickness, density and fullness. Over the course of two months, we applied the serum to clean, dry hair once a day. During this time, we refrained from using other products in our haircare routines that would encourage growth.

The Results

the ordinary hair serum review: before and after for PureWow VP of Editorial Candace Davison
Candace Davison

Candace’s The Ordinary Hair Serum Review

  • Longest hair length at start: 14.8 inches
  • Longest hair length at end: 16 inches

“The hair along my temples and at my natural part has been looking a little sparser in recent years, so I’ve been trying to encourage regrowth. I have very fine hair that breaks easily, so I was also interested in making my hair appear less stringy and a bit fuller. Day-to-day, I normally use shampoo, conditioner and heat protectant spray on the rare occasions I style it (about once a week).

The serum felt very light and runny, like a thin oil. It made my hair a bit greasy at first, but [when I] rubbed it in with a scalp massager ($18), the oily roots would disappear within half an hour. In its place, I’d have a bit more volume—likely from the serum and massager bolstering my roots a bit.

With a 9-month-old at home, I’m in the stage of postpartum hair regrowth. I expect to see baby hairs sprouting, though since using the serum, it seems there’s more of them—something my stylist commented on without me mentioning it. I’m seeing much heartier regrowth than when my first child was born, particularly where I’d been applying the serum directly. In the past, I had a few baby hairs here and there that grew back, but this time around, since using the serum, I have a fuzzy little lion’s mane popping up.

However, I think I can attribute most of the fuller, thicker hair to the fact that the product is so lightweight. That, plus the act of massaging it in really lifted my roots. My hair looked less wispy and flat, which was the end goal, so I’m happy with the results. I plan on using the serum for a few more months, just to see how it affects my hair long-term.

My one caveat is that I often want to use the serum right out of the shower as part of my get-ready routine, but it needs to be applied to a clean, dry scalp. That’s worth noting, just because it requires a little extra planning—and because you’ll need to budget in time to let the product settle in and dry, so you don’t have greasy roots.

the ordinary hair serum review before and after katherine

Katherine’s The Ordinary Hair Serum Review

  • Longest hair length at start: 9 inches
  • Longest hair length at end: 10 inches

My hair is very fine and straight with a slippery texture. The right side has always felt thinner than the left, especially near my temple. I was hoping the serum would address that thinness, especially since my 9-month-old is always tugging at my hair. My haircare routine consists of shampoo and conditioner, plus a leave-in conditioner to detangle when I brush my hair out of the shower.

Though the serum wasn’t greasy out of the bottle, I didn’t love the way it left my hair feeling after use. I kept it concentrated to one area, but I think if I were using it all over, I would need to wash my hair every morning (which I try to avoid). Regarding efficacy, I think I’d need to use the serum longer to see if it really works. While I experienced increased length, I didn’t notice a major change in density after two months. Having tried all sorts of “thickening” products and talking to my hair stylist about it, I can’t see the serum actually changing the thickness or fullness of my hair strands—that’s just genetics for me. I don’t think I noticed much change.

Lastly, this isn’t necessarily a con, but I think it’s important to have realistic expectations going in. While it’s helped with hair growth overtime, the serum isn’t an instant miracle. Optimal results will require consistent, long-term use.

the ordinary hair serum review: before and after for purewow associate editor marissa wu

Marissa’s The Ordinary Hair Serum Review

  • Longest hair length at start: 13.75 inches
  • Longest hair length at end: 15.5 inches

My hair is fine and has always lacked density. In the right light, you can see straight through to my scalp. And volume? Forget about it. I’m always looking for products that will encourage hair growth to help with the density problem. (Because no product will make your hair thicker.) My haircare routine isn’t elaborate: Shampoo, conditioner and whatever hair product I’m testing at the moment. When styling, I will use heat protectant and pile on the volumizing products, including mousse and texture spray.

Regarding the serum itself, I found it lightweight and not greasy, though it did momentarily leave my fingers tacky after I had applied it to my scalp. While Candace and Katherine noted that their roots looked greasy, I thought mine simply looked wet. However, it dried quickly and didn’t weigh my hair down. Similarly to Candace, I saw that my roots were lifted significantly, likely thanks to the aggressive massaging.

In terms of efficacy, I also echo the sentiment of my fellow editors in that the serum did encourage hair growth, but I will have to continue using it long-term to see if it affects density. My hair grows very slowly. Based on pictures from last year, I calculated that it grows roughly ¼ inch per month, compared to the average 0.41 inches. However, in the roughly eight weeks that we tested the peptide serum, my hair grew about 1.75 inches, or 0.89 inches per month, surpassing the average. Overall, I think the serum is a good value, delivering on the promise to aid hair growth at a friendly price point.

The Ordinary Multi-Peptide Serum for Hair Density

What We Like

  • lightweight formula
  • effective in encouraging hair growth
  • dries quickly
  • affordable

What We Don’t Like

  • must be applied on dry hair, not wet
  • may look greasy initially

The Ordinary

After testing The Ordinary hair serum for eight weeks, all the editors experienced above-average hair growth. It’s also easy to apply, odorless and comes in at under $25. Personally, I think that’s a good deal considering the formula is loaded with many trademarked ingredients found in other hair growth-stimulating products with much higher price points. Overall, the serum is worth a try, but go in understanding that you’ll need to play the long game to see results.

Fast Facts

  • Size: 1oz
  • Key Ingredients: REDENSYL™, Procapil™, CAPIXYL™, BAICAPIL™, AnaGain™, High-Solubility Caffeine

MW 10

Associate SEO Editor

I’ve covered the lifestyle space for the last three years after majoring in journalism (and minoring in French) at Boston University. Talk to me about all things sustainable &...

Why You Should Trust Us

PureWow's editors and writers have spent more than a decade shopping online, digging through sales and putting our home goods, beauty finds, wellness picks and more through the wringer—all to help you determine which are actually worth your hard-earned cash. From our PureWow100 series (where we rank items on a 100-point scale) to our painstakingly curated lists of fashion, beauty, cooking, home and family picks, you can trust that our recommendations have been thoroughly vetted for function, aesthetics and innovation. Whether you're looking for travel-size hair dryers you can take on-the-go or women’s walking shoes that won’t hurt your feet, we’ve got you covered.