I tried Olaplex's new scalp treatment that promises a hydrated and soothed scalp, and it actually worked

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I've tried just about every product for scalp health available, from prescription medications to serums, oils, and scrubs found at my local beauty retailers, but none have yielded very noticeable or lasting results. So, when I heard that Olaplex recently unveiled the No.0.5 Scalp Longevity Treatment — a serum designed to hydrate and soothe the scalp, balance the scalp microbiome, and strengthen hair from the root — I decided to give it a shot.

The truth is, I've had a complicated relationship with my scalp from the day I was born. As a baby, I was diagnosed with the infant form of dandruff commonly known as "cradle cap," — and this manifested into never-ending flare-ups of seborrheic dermatitis as an adult. (Using dry shampoo, bleaching my strands, and blasting my poor scalp with heat from my hairdryer probably doesn't help.) After a long, dry winter, my scalp has been in particularly rough shape. So, it felt like the perfect time to test out the new Olaplex scalp treatment, which just hit shelves in February of 2025.

This treatment has already been garnering some major praise from TikTok beauty influencers. But does it live up to the hype? In this Olaplex Scalp Longevity Treatment review, I'll share my honest thoughts after using it several times for a week.

How to use the Olaplex No.0.5 Scalp Longevity Treatment

The Olaplex Scalp Longevity Treatment can be used on either clean, wet hair before styling or on dry hair. For the purposes of this review, I tried both.

Whichever route you choose, the first step is sectioning your hair. I have fine hair, but I also have a lot of it, so I parted my hair down the middle and separated each side into two sections — for four total.

The treatment comes with a needle-nose applicator, so it's super easy to apply the product to your scalp precisely. I squeezed some down the center line of my scalp and then worked my way down in vertical lines spaced about an inch or two apart from the crown of my head to the nape of my neck. Since I tend to experience more flakes and scaling around my hairline, that's where I concentrated more of the product.

After applying, I massaged the treatment in with my fingers to distribute it evenly.

Olaplex claims the treatment is gentle enough for daily use but recommends using it three times per week for best results.

Olaplex No.0.5 Scalp Longevity Treatment Review

The first thing I noticed about the Olaplex treatment is that it has a very similar milky white appearance and texture to the brand's cult-favorite No.3 Hair Perfector.

One of my pet peeves is when scalp treatments don't come with a fine tip to help with precise placement, and the ultra-fine tip on this bottle makes application a breeze. I was able to deliver the product directly to my scalp without getting too much in my hair.

Many scalp treatments I've tried feel a little too oily and heavy for my liking, weighing down my roots. I was worried that this product might make my hair feel greasy, but that definitely wasn't the case — even when I applied it to my dry hair that wasn't super clean. As always, I was able to wait two to three days in between shampooing.

I love an excuse to give myself a good scalp massage, and once I rubbed the product in, the skin on my scalp felt noticeably less tight and dry.

When I applied the treatment on wet hair and then blow-dried it, I noticed a slight boost in shine and volume at the root.

The perks weren't quite as obvious when I applied it to dry hair, but I will say that I found it much easier to massage evenly into my scalp when my hair wasn't wet. I also felt a subtle cooling sensation on my scalp when I applied it to dry hair, which I certainly didn't hate.

Olaplex No.0.5 Scalp Longevity Treatment ingredients

After researching the Olaplex No.0.5 Scalp Longevity Treatment formula's ingredients, I admit I'm impressed: every single one appears to serve a function — no fillers here. I was surprised to find that not only are many of these ingredients nourishing for the scalp, but they may also help to play a role in supporting hair growth. I also appreciate that this scalp treatment doesn't contain any artificial fragrances, which can be super irritating to sensitive skin like mine.

Here are some of the standout ingredients in the Olaplex Scalp Longevity Treatment, along with some of the benefits they offer:

• Bis-aminopropyl diglycol dimaleate: This is the patented ingredient used in all Olaplex. It works by reconnecting and strengthening broken disulfide bonds in the hair that have been damaged by exposure to excessive heat, chemical treatments, environmental aggressors, and rough handling.
• Arginine: Studies have shown that a deficiency in this amino acid is associated with hair loss. Researchers believe that arginine may be beneficial because it can improve blood supply to the hair roots, thereby stimulating growth, and also because it has a protective effect against damage.
• Rice bran oil: A 2022 review found that when applied topically, rice bran extracts can promote hair growth by curbing inflammation, reducing the enzyme that shortens the hair growth cycle and causes hair follicles to shrink, and increasing cell growth during the anagen phase — during which hair is actively growing.
• Hydrogenated polydecene: This ingredient acts as an emollient, meaning that it can prevent moisture loss, soothe irritated skin, soften dry skin, and soften peeling or scaling skin. Emollients are often recommended to help treat eczema, psoriasis, and dermatitis.
• Glycerin: The American Academy of Dermatology Association calls glycerin one of the best ingredients for dry skin. Research has shown that glycerin can increase skin hydration levels, protect the skin from irritation, and strengthen an impaired skin barrier function.
• Soybean seed extract: Some studies suggest that topical application of soybean extracts can reduce hair loss. In fact, researchers are exploring the use of soybean extract as a viable alternative for prescription hair loss medications like minoxidil and finasteride, which are associated with some unpleasant side effects.
• Ceramide NP/ceramide EOP: Half of the epidermis — the outer layer of your skin — is made up of naturally occurring fats known as ceramides. They play an important part in maintaining hydration and shielding the skin from toxins and irritants.
• Patchouli (pogostemon cablin) extract: A 2023 study found that applying this particular plant extract to the scalp helped to normalize sebum levels on the skin, balance the scalp microbiome, and increase the presence of certain bacteria that are crucial for a strong skin barrier. It's worth noting that an imbalance of sebum production is associated with common scalp issues like dandruff and seborrheic dermatitis.
• Leptospermum scoparium branch/leaf oil: This essential oil is extracted from the Manuka tree in Australia in New Zealand. Research indicates that it has antibacterial, antifungal, and anti-inflammatory properties — and may even help protect the skin from damage caused by UV radiation.
• Magnolia bark extract: The superstar substance in this extract is honokiol, which has anti-inflammatory and antioxidant properties. Emerging animal studies suggest that honokiol may even be effective in promoting hair growth.
• Hyaluronic acid: The benefits of hyaluronic acid are well-researched. This humectant can combat dryness by pulling moisture into the skin on the scalp. A 2022 study revealed that treating damaged hair with hyaluronic acid can strengthen it, making it more elastic and, therefore, less susceptible to breakage.
• Lavender oil: Not only does lavender have antimicrobial properties, but some animal studies show that it may help hair to grow faster and thicker.

The bottom line

My scalp is — for lack of a better word — finicky and hard to please. It's dry, but it also gets greasy quickly. What I love about the Olaplex Scalp Longevity Treatment is that it contains clinically proven ingredients to address both issues: helping the skin on my scalp retain moisture while also regulating sebum.

While it's too early to tell whether the treatment will help with my hair growth goals, I'm optimistic about monitoring that extra potential perk with regular use in the coming months.

At the very least, the Olaplex Scalp Longevity Treatment makes my scalp feel hydrated and nourished, minimizes flakes, and even gives me a much-appreciated little boost in shine and volume. Given the science-backed formula and my own positive experience after just a few uses, I can confidently say it's worth the $44 price tag.