Index / The Ordinary / Multi-Peptide Serum for Hair Density
The Ordinary

Multi-Peptide Serum for Hair Density.

The Ordinary Multi-Peptide Serum for Hair Density
Haircare

About this product

A water-based scalp serum combining peptides (Redensil, Procapil, Capixyl, Baicapil) and caffeine, designed to support hair density and scalp health.

Full ingredients

Guru Score

69%

Mixed

13 experts · Strong agreement
13Gurus
7Yay
4Mixed
2Nay

What they liked

  • Water-based, lightweight texture
  • Keeps scalp hydrated in winter
  • Very affordable

What they flagged

  • May irritate sensitive scalps
  • Ingredient concentrations not disclosed
  • Results take at least three months to assess

What the gurus are saying

This serum earns praise for its stacked ingredient lineup at an affordable price, though results vary widely. Several experts love it for keeping dry scalp hydrated without greasiness, especially in winter, and some report visible improvements in hair density over months of consistent use. The main split: a few gurus found it left a greasy residue on hair strands or saw no change after three months, while others experienced noticeable thickening. Those with sensitive scalp may want to patch-test first, as polysorbate 20 and castor oil can trigger flare-ups. Best results come with patience (expect at least three months) and targeted application to thinning areas rather than whole-head coverage.
Synthesized from 13 expert reviews · most recent take July 2026

What the gurus are saying.

Every take we've logged from this product's reviews across YouTube. Click any row to watch the moment they said it.

All takes Yay takes Nay takes Mixed takes Hide sponsored
~Mixed
"There's also The Ordinary Hair Serum, which combines Capixyl, Redensyl, and Procapil. There's definitely a lot less data on this one, but these peptides have such a wide range of benefits for hair growth, hair structure, and hair fullness that they would theoretically probably also help with eyebrow fullness, though more in a supporting role. There's some good data on these ingredients, and I think Capixyl acts very similar to minoxidil, so there's some overlapping benefit if you want a safer alternative to the other options out there."
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"The Ordinary one is a combination of Redensil, Procapil, Capixyl and Baicapil, which is actually pretty stacked for an Ordinary product. I think that's a really good affordable option if you're looking to enter into this space. There's not one that I particularly currently love, but if I was going to try one in this space, I would try probably the one from The Ordinary."
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"There's also The Ordinary Hair Serum, which combines Capixyl, Redensyl, and Procapil. There's definitely a lot less data on this one, but these peptides have such a wide range of benefits for hair growth, hair structure, and hair fullness that they would theoretically probably also help with eyebrow fullness, though more in a supporting role. There's some good data on these ingredients, and I think Capixyl acts very similar to minoxidil, so there's some overlapping benefit if you want a safer alternative to the other options out there."
~Yay
"You can find these in The Ordinary Multi-Peptide Serum for Hair Density. I love this one cuz it's super affordable."
~Mixed
"I was using The Ordinary Multi-Peptide Serum for Hair Density before I started using minoxidil, and I loved it. It uses the same grouping of ingredients as other formulas, but what I like about alternatives is that they state the exact concentration of the different ingredients in the formula because they all comply with what the successful testing was based on."
~Yay
"I love this stuff. The Ordinary Multi-Peptide Serum for Hair Density, which will be $18 during the sale. It's a water-based scalp serum for hydration and building root strength. And it's got some actually really interesting peptides in here which have been studied and shown to help with hair growth, hair density at the root. So it's got caffeine in there. Caffeine is used in a lot of lash serums as well and also eye serums for puffiness. It's got apigenin, which is a flavonoid, which makes it a super strong antioxidant. Also used in hair products. Wheat germ extract. It's got green tea. It's got biotinoyl tripeptide 1, which is a peptide claimed to be helpful for reducing hair loss. And it's also known for making eyelashes appear longer, fuller and stronger. It's got acetyl tetrapeptide 3, which is a four amino acid peptide that has been researched and promises to help combat hair loss. So two or three really exciting ingredients in this. [...] I use this more on my scalp to keep it hydrated during the winter."
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"The Multi-Peptide Serum for Hair Density is really nice. It [...] has some proven or really studied ingredients to help with hair follicles. [...] I like it because during the winter it keeps my scalp hydrated and it doesn't feel as dry. It's a nice option if you get really dry scalp issues. It's water-based and it doesn't feel greasy. I apply it when I get out of the shower on the part and then a couple other parts, [...] once or twice a week during the winter. I typically don't use it too much in the spring and summer when my scalp isn't very dry, but it's nice for that. If you have issues with hair density, it's certainly worth trying."
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"For hair care, my most repurchased product is the Multi-Peptide Serum for Hair Density. I don't use it so much during the summer, but in the winter when my scalp gets dry, I use this every other night on wet hair, just a little bit, a couple drops on my scalp, and it does the trick. It prevents dryness and it really helps. This one's well worth checking out if you suffer from dryness issues on your scalp."
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"The Ordinary Multi-Peptide Serum for Hair Density has a water-like texture and I use this more as a hydrating product than a hair growth product because I find it gives my scalp just enough moisture so that in the winter it doesn't get dry and flaky. [...] I didn't really notice anything in terms of hair growth, but that's not my main issue. My main issue is moisture in the scalp and this one has done the trick for me for winter."
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"Next up is The Ordinary Multi-Peptide Serum for Hair Density, which I love."
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"I've repurchased this probably [...] a dozen or so times over the years. The bottle is a little bit larger than the average serum and it's just got a nice water texture. I typically use this more in the winter when my scalp gets dry and I just apply a little bit to my part right after getting out of the shower, let it soak in and go. Nothing else you need to do. It's very hydrating and leaves my scalp feeling not dry or flaky."
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"The Ordinary Multi-Peptide Hair Density Serum, I use this one more for dry scalp than hair density, although nowadays my hair density needs all the help it can get as well. So this one's nice. If you didn't pick it up during the Ordinary sale, it's really nice. Fragrance-free. [...] Copper peptides are great for the root and the hair follicle."
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"The ordinary natural moisturizing factors Scalp Treatment I'd use this every night uh I was going through it like every other month because I didn't necessarily use it for hair density but I use it more for um hydrating the scalp without it being greasy"
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"I used to use [The Ordinary Multi-Peptide Serum for Hair Density] [...] on its own a lot. Not for hair density so much, just for dry scalp, and it really helps with that."
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"This is my newest bottle of it. I've repurchased this one probably tens of times. It's just a really nice serum with peptides in there, which also include 1% copper peptides, which are really good for your skin and anti-aging. It's got a blue color to it. It's got copper peptides, argilene peptide which is the botox in a bottle peptide, then it's got the Matrix Metalloproteinase 3000 peptide duo which helps slow down collagen degradation in skin, and also has the Matrix salt synthesis peptide which is another one for anti-aging. Then we've also got several amino acids which are skin identical ingredients, building blocks for skin. Urea and lanolin, which is a great soothing ingredient. So this one's really nice even at $32, it's still a wonderful product and I will still purchase it. If that's a little bit too expensive, then I don't know what to do. If it's too expensive, there's not a lot of real options that are cheaper than that."
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"Their Multi-Peptide Serum for Hair Density is really nice and hydrating on my scalp. It's $22.80 and it's got a couple of actual proven ingredients to help with hair loss and hair density. It's got biotin oil tripeptide one, which is an amino acid peptide where the collagen fragment is combined with biotin to help supplement for stronger nails and hair. It's got acetyl tetrapeptide-3, which stimulates the synthesis of key extracellular matrix, which is the gooey stuff in between the cells that make up the framework of our skin components in the scalp, resulting in stronger hair bed anchoring. It contains green tea and apigenin. It's a great product. There's no scent to it. [...] It doesn't leave your hair scalp feeling greasy. I just put it in after a shower when my hair is wet, just a few drops."
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"I love this stuff. The Ordinary Multi-Peptide Serum for Hair Density, which will be $18 during the sale. It's a water-based scalp serum for hydration and building root strength. And it's got some actually really interesting peptides in here which have been studied and shown to help with hair growth, hair density at the root. So it's got caffeine in there. Caffeine is used in a lot of lash serums as well and also eye serums for puffiness. It's got apigenin, which is a flavonoid, which makes it a super strong antioxidant. Also used in hair products. Wheat germ extract. It's got green tea. It's got biotinoyl tripeptide 1, which is a peptide claimed to be helpful for reducing hair loss. And it's also known for making eyelashes appear longer, fuller and stronger. It's got acetyl tetrapeptide 3, which is a four amino acid peptide that has been researched and promises to help combat hair loss. So two or three really exciting ingredients in this. [...] I use this more on my scalp to keep it hydrated during the winter."
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"The regular Buffet which they renamed I think they renamed it their natural moisturizing Factor plus AJ serum anti-aging serum that's still that's great"
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"I really enjoy this stuff. I just typically use it in the fall in Winter and maybe at the beginning of Spring, just a couple drops down my part and it helps my scalp stay hydrated and it prevents some flakiness and things like that. My scalp tends to get dry in the winter. [...] I used to use it year round and now in the spring and fall it seems okay now without it."
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"If you have hair loss, [...] you could buy the powder and mix it into something like The Ordinary Multi-Peptide Serum for Hair Density. That's probably what I would do. [...] If you have issues with hair growth, I think that'd probably be well worth a try."
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"The Ordinary Multi-Peptide Serum for Hair Density, I found this stuff to be really lovely, non-greasy. I just apply a little bit, a couple drops to my part right after showering and it soaks in and feels nice. No hydrant, no dandruff, any itchiness, dryness or anything like that. It really helped make a huge difference. I use it maybe once a week and it really is nice. During the winter I'll use it more, right now it's summer I don't really have as many issues with dryness, but during the winter I use it usually every other shower. So it's really lovely, lovely product overall."
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"The Ordinary Multi-Peptide Serum for Hair Density is 17 bucks right now. It's a hydrating scalp serum that's meant to help with hair growth and slow hair loss. It's got a really light water texture to it so I just use this when I get out of the shower. I use it a lot during the winter. I apply this to my part and then let it soak in overnight and it's fine. [...] In here we've got caffeine, we've got peptides, we've got pea extract, we've got skull cap root extract, we've got green tea, we also have a wheat germ extract which is a great ingredient used in many hair conditioners as well as face creams as a protecting ingredient."
~Mixed
"I was trying this for 7 days, my scalp is seriously sensitive, and I used it in conjunction with Minoxidil so I did Minoxidil in the morning and this at night. My scalp flared up, and I looked at the ingredients and there's two things in there that would cause that: Polysorbate 20 as well as castor oil. So people use castor oil a lot for hair loss but it actually irritates the scalp a lot as well. So [...] if you've got a sensitive scalp I would actually stay away from this product. But if you've just got hair that maybe you've heat treated too much, you've got split ends, it could look a little bit healthier, fuller, and you don't have male and female pattern hair loss, then this product is good. If you've got male and female pattern hair loss, like Yours Truly, then stick to what you're using that's FDA approved for hair loss and you can use it as an add-on just to improve the health of your hair. That's how you should be using this product. [...] I think it's got some decent ingredients in there, nothing really too strong. I would probably not use this myself because for me, Minoxidil and my one tablet a day have stopped my hair from going further back."
~Yay
"I have been using the Multi-Peptide Serum for Hair Density from the ordinary and it cost about 15 bucks."
~Mixed
"The Ordinary Multi-Peptide Serum for Hair Density is a very peptide forward serum to promote hair growth. It's a water-based formula which is so easy to use on your scalp. I'm not going to guarantee your hair growth or anything, but definitely in conjunction with some physical stimulation with a scalp brush and these wooden tools would be worth trying."
~Yay
"They do sell SK SCP moisturizer a pretty inexpensive product from the ordinary it's their natural moisturizing Factor plus ha for scalp uh fragrance-free it's lightweight it's hydrating Ura and lactic acid in this formula are hydrating and can soften and exfoliate dry skin they're part of your Skin's natural moisturizing factors so they're helpful for moisture retention this formula goes into the scalp very easily and doesn't really leave any kind of residue on the hair strands"
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"There's something to be said about scalp massage [...] improving blood flow, and that combined with the caffeine in this could potentially help you get a healthier hair follicle in theory. [...] For me personally, I found this product to be a little bit messy. It did leave a residue on my hair strands that made them look kind of greasy. I [...] noticed that residue developing after one week of using it. I continued to use it, but I was more conservative with the volume that I used because of the effects that it had on the appearance of my hair. [...] I would suggest if you do have thinning in certain areas to just use it in those areas to see if it benefits you. [...] This is not the kind of thing that you are going to see results overnight. [...] It takes at least three months to see any sort of change. I have used this consistently for over three months and saw no change. [...] Given how it looked on my hair, I just was not motivated to continue using it. It's free of fragrance and it's not irritating. If you do have more patchy areas of significant thinning, you may find that it ends up moisturizing your scalp and you may like that aspect of it. For me, it ends up mostly on my hair strands, leading to the appearance of greasy hair."
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"They do sell SK SCP moisturizer a pretty inexpensive product from the ordinary it's their natural moisturizing Factor plus ha for scalp uh fragrance-free it's lightweight it's hydrating Ura and lactic acid in this formula are hydrating and can soften and exfoliate dry skin they're part of your Skin's natural moisturizing factors so they're helpful for moisture retention this formula goes into the scalp very easily and doesn't really leave any kind of residue on the hair strands"
~Yay
"The multipeptide serum is the one I have repurchased a number of times. When I finished the copper peptide version of it, I didn't feel it did anything for me in addition to this regular multipeptide serum, which is why this is the one I keep going back to."
~Yay
"I've been using The Ordinary Multi-Peptide Hair Serum and it's been working for me, my edges were struggling a little bit and now it's working. I just started using it so I can't tell you much yet, but I do have knowledge on ingredients, and this one has a lot of patented ingredients like Redensyl, Procapil, Capixyl, Baicapil and Anagain, and caffeine, which are really strong ingredients that I'm really impressed by, and that's what made me want to buy this product. My only wish is that they disclosed how much Redensyl is actually in it, since it's patented they never will. I'm excited to use it and see what it does."
~Nay
"Speaking of hair serums, the one that was the fail this summer was The Ordinary scalp serum. It just didn't do anything. It's very heavy, it weighed down my hair. None of the other serums that I've tried, the Hail, Vegamore, or my Rogaine foam, as long as I apply it correctly just to the scalp, the part areas that I create, and apply it in very small amounts, none of that weighs down my hair. It just really encourages healthy scalp and hair growth. However, I didn't find that this was very easy to use. It made my hair kind of sticky and tacky. So as a scalp serum, this is going to be a pass for me."
~Yay
"I've gone through two bottles of it and I just stopped using it for a while and you can just see the results. I'm going to do a whole review on all the things that I have done since January which include The Ordinary Multi-Peptide Serum for Hair Density, and there are a lot of things that [...] have resulted in hair growth and which have just resulted in my hair being healthier."
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"I've gone through two bottles of it and I just stopped using it for a while and you can just see the results. I'm going to do a whole review on all the things that I have done since January which include The Ordinary Multi-Peptide Serum for Hair Density, and there are a lot of things that [...] have resulted in hair growth and which have just resulted in my hair being healthier."
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"My scalp was very, very healthy and nourished, not oily but it felt nourished. I had a few white hairs so I was very happy about hair growth. I did not see a massive change, so I'm not saying this is a bad product, it's a good product, but it's not massive changes. This has biotin, it has dry extracts, it has caffeine, it has a lot of good peptides as well. This has better hair growth ingredients than The Ordinary hair density and this was working fabulously on me."
~Nay
"I also tried this from The Ordinary the Multi-Peptide Serum for Hair Density I just didn't see big results with this. A lot of people have said this is amazing for them maybe I didn't use it for enough months I just didn't see the biggest results so I might retry outing this or I might just say screw it."
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"I also tried this from The Ordinary the Multi-Peptide Serum for Hair Density I just didn't see big results with this. A lot of people have said this is amazing for them maybe I didn't use it for enough months I just didn't see the biggest results so I might retry outing this or I might just say screw it."
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"The Ordinary is one that I tried, I think this was 2022 that I tried this. I was just not impressed by this. This was one of the Ordinary products I didn't love. This is the Multi-Peptide Serum for Hair Density, but I'm wondering if I didn't use it right."
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"The Ordinary also has the Buffet, which I think they just renamed. These are both great but they do tend to get a little bit gummy."
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"I was so excited about these when I first tried them and I've actually been through multiple bottles, but I feel like all they've done is run down my scalp and make it greasy. I really can only really use this when my hair is curly because otherwise it ruins the smoothing that I do to my hair. I just found that while this is great to moisturize the scalp if you have dry patches, I didn't see a big difference when it actually came to my hair's thickness or density or my actual hair roots. Overall I had really high hopes of these and they were a little bit disappointing for the price."
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"This is quite different from the NMF HA that goes on the skin. This has a much milkier formula and they do say this is specifically made for the scalp. This does have specifically fructose, sucrose and glucose, plus manganese PCA, zinc PCA, magnesium PCA, urea which is mildly exfoliating, as well as lactic acid which is also mildly exfoliating. So I could actually see this being really beneficial for people who have scalp buildup and a dry scalp. You're supposed to put this on when you're not in the shower and massage it in at night as a leave-in treatment. This is actually very interesting. I love all of the amino acids in here. It comes in at 12.80, and comparing that to everything else on the market especially for a scalp serum this is not bad. The main ingredients are hyaluronic acid and squalene, so really focused on delivering hydration and moisture into the scalp and locking it in. This is a much more liquidy formula. I feel like the closest comparable product from the Inkey List would be their hyaluronic acid hydrating hair treatment, but this seems to be more of a scalp hydrator whereas that is more of a frizz control serum."
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"This is an inexpensive one and I'm only testing it on half of my head to see how it actually works. This is the multipeptide serum for hair density. A lot of people have had reviews on this and said that it's really, really good. I am trying to not be a Debbie Downer, but I have not seen the most with it. But I'm also just about a month in and I'm going to be buying another bottle because this is going away very quickly. So far it drips down my scalp and it gives me an uncomfortable feeling. It kind of makes my hair a little bit greasy."
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"So far my scalp has been liking it. It's a little greasy, but their hair serum and their conditioner have actually grown pretty good, and for eight dollars, that's a follow-up with my testing experience coming soon."

What the evidence says.

Independent of what the gurus think, this is what the published research supports about the main active ingredients here.

Alpha hydroxy acids

Alpha hydroxy acids loosen the bonds holding dead cells at the surface. The evidence supports smoother texture and more even tone over time, and they can leave skin more sensitive to sun.

Source: NIH, National Library of Medicine

Peptides

Peptides are short protein fragments meant to signal repair. The evidence for them is thinner than for retinoids or vitamin C, and it varies a lot by the specific peptide, so the category is more promising than proven.

Source: NIH, National Library of Medicine

Frequently asked.

What is The Ordinary Multi-Peptide Serum for Hair Density?

A water-based scalp serum combining peptides (Redensil, Procapil, Capixyl, Baicapil) and caffeine, designed to support hair density and scalp health.

Is The Ordinary Multi-Peptide Serum for Hair Density worth it?

The gurus are split. 7 of the 13 gurus give it their stamp of approval while 2 would skip it, which lands it in the middle at a Guru Score of 69%.

What is The Ordinary Multi-Peptide Serum for Hair Density's Guru Score?

The Ordinary Multi-Peptide Serum for Hair Density holds a Guru Score of 69%. That is our read on how warmly the experts talk about it, based on the verdicts of 13 expert reviewers we have collected. At least one expert has named it a Top Pick in its category.

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