Most of us treat the skin on our heads like it’s a completely different species from the skin on our faces. It's weird. We spend hundreds of dollars on multi-step facial routines but then blast our scalps with harsh clarifying shampoos and hope for the best. If you've ever dealt with that tight, itchy, "my-head-is-two-sizes-too-small" feeling, you know exactly what I’m talking about. This is where The Ordinary Natural Moisturizing Factors + Hyaluronic Acid Scalp Serum comes into play, and honestly, it’s about time we stopped ignoring the scalp-skin barrier.
Dryness isn't just about flakes. It’s about hydration.
Most people see a flake and immediately reach for a coal tar shampoo or something designed to kill fungus. But sometimes, your scalp is just thirsty. This specific milky serum from The Ordinary isn't a dandruff treatment in the traditional sense; it’s a barrier support system. It uses ingredients your body already recognizes to keep moisture from evaporating into thin air.
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What is actually inside The Ordinary Natural Moisturizing Factors + Hyaluronic Acid Scalp Serum?
The name is a mouthful. We’ll just call it the Scalp NMF. If you’ve used their famous face moisturizer, you already know the vibe. It’s designed to mimic the Natural Moisturizing Factors (NMF) that occur naturally in our stratum corneum. These are things like amino acids, fatty acids, triglycerides, urea, and ceramides.
Why does this matter for your hair?
Well, your hair grows out of your scalp. Revolutionary, right? But a compromised scalp barrier often leads to inflammation, which can eventually mess with your hair follicle health. The Ordinary included Hyaluronic Acid and Squalane in this formula to provide both immediate hydration and a bit of a "seal" to keep that water in. It’s a water-based serum, which is a huge deal for anyone who hates the feeling of greasy hair.
Let’s be real for a second: putting "oil" on a dry scalp often just results in oily flakes. This is different. It’s lightweight. It disappears.
The Science of the Scalp Barrier
The scalp has a higher density of sebaceous glands than almost anywhere else on the body. It’s also incredibly vascular. However, because we wash it frequently—often with sulfates—we strip away the lipid mantle. Research published in the Journal of Clinical and Aesthetic Dermatology suggests that scalp hydration is a major factor in "trichodynia," which is that weird "hair pain" or sensitivity some people get.
By applying The Ordinary Natural Moisturizing Factors + Hyaluronic Acid Scalp Serum, you are essentially reinforcing the "mortar" between your skin cells. The amino acids like Arginine, Aspartic Acid, and Glycine in the formula act as humectants. They grab onto water. The Squalane acts as an emollient. It smooths things over. It’s a team effort.
How it feels when you actually use it
It’s runny. Like, really runny. If you aren't careful, it’ll drip down your neck before you can rub it in. The bottle comes with a nozzle that allows you to get right to the roots, which is helpful because you want this on your skin, not your hair strands.
You’ve probably seen influencers drenching their heads in this stuff. Don't do that. You only need a few drops per section. If you overdo it, your hair might feel a little "product-y" the next morning, but it generally dries down to nothing.
One thing I’ve noticed—and several long-term users on forums like r/SkincareAddiction have pointed out—is that it doesn't have a scent. No fragrance. No essential oils. For anyone with a sensitive, reactive scalp, that is a massive win. Fragrance is one of the biggest triggers for contact dermatitis on the scalp.
Will it make your hair greasy?
This is the number one question. Honestly, it depends on your hair type.
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If you have fine, thin hair, apply it at night. Give it those 8 hours to sink in while you sleep. If you have thick, curly, or extremely dry hair, you might be able to get away with using it on damp hair after a wash without it weighing you down at all. Most people find that because it’s a "Natural Moisturizing Factors" formula, the skin drinks it up rather than letting it sit on the surface like a heavy castor oil might.
Common misconceptions about scalp hydration
People often confuse a dry scalp with seborrheic dermatitis. They are not the same.
If your scalp is oily but also flaking with yellowish, greasy scales, you probably have "seb derm." In that case, The Ordinary Natural Moisturizing Factors + Hyaluronic Acid Scalp Serum might feel nice, but it isn't going to fix the underlying fungal issue. You’d need something with Ketoconazole or Zinc Pyrithione for that.
However, if your scalp feels tight after a shower, or if you get tiny "snow" flakes that are dry and white, your barrier is likely just thirsty. That is exactly where this serum shines. It’s for the "thirsty" crowd, not the "fungal" crowd.
Does it help with hair growth?
The Ordinary is very careful about this. They don't claim it grows hair. That’s what their Multi-Peptide Serum for Hair Density is for.
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Think of it like a garden. The NMF serum is the fertilizer and the water that makes the soil healthy. While it won't magically wake up dead follicles, a healthy, hydrated scalp environment is the bare minimum requirement for optimal hair growth. If your "soil" is cracked and dry, your "plants" aren't going to thrive. It's simple logic, really.
The price point versus performance
It’s cheap. Usually under $15 for 60ml.
Compared to high-end scalp treatments from brands like Sisley or Dr. Barbara Sturm, which can run upwards of $100, The Ordinary is basically a steal. But you have to manage your expectations. It’s a basic, functional hydrator. It’s not a "luxury experience." The packaging is utilitarian. The texture is functional.
But it works.
If you look at the ingredient list, you’re getting a lot of "skin-identical" ingredients. Sodium PCA, Urea, Allantoin, and various Minerals. These aren't flashy, trendy ingredients like "Blue Tansy" or "Moonstone Extract," but they are what the skin actually needs to function.
How to integrate it into your routine
You don't need to use this every single day unless your scalp is severely compromised.
- Step 1: Use the nozzle to apply a few drops to key areas (hairline, crown, and behind the ears).
- Step 2: Massage it in thoroughly using your fingertips, not your nails.
- Step 3: Leave it on. Do not rinse it out.
- Step 4: If you find it leaves a residue, switch to nighttime application only.
Some people like to mix a few drops into their leave-in conditioner, but honestly, it works best when it has direct contact with the skin.
Real world results and limitations
No product is perfect. Some users find the inclusion of Squalane, while great for the skin, can be a bit much for very oily hair types. If you struggle with excess sebum production, you might find that this makes you feel like you need to wash your hair a day sooner than usual.
Also, the bottle is 60ml. If you have a big head or use it every single night, you're going to burn through it in about three weeks. It’s not a giant bottle.
But for the price of a fancy latte, it’s one of the few scalp treatments that actually addresses the moisture barrier without relying on "cooling" sensations from peppermint or menthol, which often just mask the irritation rather than fixing it.
Actionable Next Steps for Scalp Health
If you're ready to stop the itch and actually fix your scalp barrier, here is how to move forward:
- Identify your issue: If your scalp is red, itchy, and oily, see a dermatologist to rule out Seborrheic Dermatitis before starting a hydration-only routine.
- Patch test: Even though it’s fragrance-free, some people are sensitive to high concentrations of Urea or certain amino acids. Drop a bit behind your ear first.
- Nightly Application: Start by using The Ordinary Natural Moisturizing Factors + Hyaluronic Acid Scalp Serum three times a week at night. Observe how your hair looks the next morning before moving to daily use.
- Pair with a gentle wash: Don't undo all your hard work by using a harsh, stripping shampoo. Look for "sulfate-free" or "pH-balanced" cleansers that won't destroy the NMF you're trying to replace.
- Be consistent: Skin turnover takes about 28 days. Don't expect your scalp to feel completely "new" after one application. Give it a full month to see if that tight feeling finally goes away.