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The Ordinary

Multi-Peptide Serum for Hair Density.

The Ordinary Multi-Peptide Serum for Hair Density
Haircare

About this product

A leave-in scalp serum from The Ordinary that uses a blend of peptides and caffeine to support the look of fuller, denser-appearing hair, not a treatment for pattern hair loss.

Haircare

The Guru Index verdict

63%

Mixed

~Mixed · 63%
7Reviewers
2Approved
4Mixed
1Skip
#11 in Best Haircare

What the gurus are saying

Gurus overwhelmingly praise this serum as a hydrating scalp treatment, especially for winter dryness and flakiness, with many repurchasing repeatedly. The consensus is that it excels at moisture and scalp comfort rather than dramatic hair growth. A few reviewers saw no significant density results or didn't notice changes, and one noted potential irritation from castor oil and polysorbate 20 for sensitive scalps. One reviewer flagged that ingredient concentrations aren't disclosed, limiting confidence in efficacy claims.
Synthesized from 7 expert reviews

Key actives & flags

AHAPeptidesFragrance-freeAlcohol-free

Full ingredients

Aqua (Water), Propanediol, Butylene Glycol, Glycerin, Caffeine, Biotinoyl Tripeptide-1, Acetyl Tetrapeptide-3, Larix Europaea Wood Extract, Pisum Sativum Extract, Scutellaria Baicalensis Root Extract, Triticum Vulgare Germ Extract, Glycine Soja Germ Extract, Trifolium Pratense Flower Extract, Camellia Sinensis Leaf Extract, Apigenin, Oleanolic Acid, Arginine, Glycine, Calcium Gluconate, Zinc Chloride, Lactic Acid, Gluconolactone, Dextran, Maltodextrin, Hydroxyethylcellulose, Xanthan Gum, Pentylene Glycol, Dimethyl Isosorbide, Polysorbate 20, Ppg-26-Buteth-26, Peg-40 Hydrogenated Castor Oil, Trisodium Ethylenediamine Disuccinate, Sodium Metabisulfite, Sodium Benzoate, Phenoxyethanol, Chlorphenesin

Every take, in full

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 Approved only Skip only Mixed only Hide sponsored
~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."
Approved
"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."
Top Pick: most repurchased hair care product
All 12 takes from No BS Beauty
I Tested Everything from The Ordinary & NIOD 🙌😍 Don’t Buy Until You See This! Slowvember Sale
"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."
The Only Products From The Ordinary I've Repurchased - And I've Tried Them All!
"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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"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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"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."
I've Tried Every Product From The Ordinary & These are the Skincare I'm Still Using Years Later
"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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"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."
My Most Repurchased Skincare Products - My Most Loved & Used Skincare
"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."
Skip
"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."
All 2 takes from Cassandra Bankson
f it... i'm microneedling my scalp? (everything i'm doing for my hair loss) [Dec 2023]
"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."
My Hair Growth Update…
"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."
~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."
~Mixed
"I massaged a few drops into the scalp at bedtime. For me personally, I did not experience any change in hair density or hair thickness. My hair looked exactly the same. In terms of the aesthetics and the feel, I really did not enjoy using it. I found that it made my hair appear very greasy. I'm skeptical that the results I could get with this alone would compare to what I've achieved with other treatments I use. This didn't add anything, so for me personally it's not something that I would ever continue to use on an ongoing basis."
All 4 takes from Dr Dray
THE ORDINARY HAIR DENSITY SERUM | Dermatologist Review
"I massaged a few drops into the scalp at bedtime. For me personally, I did not experience any change in hair density or hair thickness. My hair looked exactly the same. In terms of the aesthetics and the feel, I really did not enjoy using it. I found that it made my hair appear very greasy. I'm skeptical that the results I could get with this alone would compare to what I've achieved with other treatments I use. This didn't add anything, so for me personally it's not something that I would ever continue to use on an ongoing basis."
THE ORDINARY HAIR DENSITY SERUM | Dermatologist Review
"In terms of the aesthetics and feel, I really did not enjoy using it. I found that it made my hair appear very greasy. I'm skeptical that the results I got with other methods could be replicated with this alone. This didn't add anything, so for me personally it's not something that I would ever continue to use on an ongoing basis. The caffeine in this is probably one of the more evidence-based ingredients, and there's something to be said about scalp massage improving blood flow that combined with the caffeine could potentially help in getting a healthier hair follicle in theory. But 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 did not care for that."
THE ORDINARY HAIR DENSITY SERUM | Dermatologist Review
"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."
THE ORDINARY HAIR DENSITY SERUM | Dermatologist Review
"If you're someone who is motivated to introduce a caffeine serum to the scalp, this is a reasonable option. Don't expect a miracle, however. Don't get your hopes up too high. Caffeine shows promise for some people with hair thinning just for improving the nutrient delivery to that high metabolic demand hair follicle, and it could help in theory with improving the falls of the hair follicle. Caffeine shows promise for reducing shedding with telogen effluvium, so if you're going through that and the cause has been addressed and you're just waiting to get your hair back on track, I think this is a reasonable option to introduce. In theory it can help reduce the shedding phase for you, but I want to make it clear this hasn't been studied in that regard."
Approved
"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."
All 2 takes from Nipun Kapur
Skincare Live! Taking your questions | Nipun Kapur
"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."
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