$40 Unwritten Hair serum that transform damage in two hours
This five-star product is proven to transform hair within hours — and it’s approved by hairdressers across Australia.
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Looking at my dry, lifeless and dead-straight hair, you can probably tell I’ve never been big on hair products.
Yes, it’s probably because I focus most of my effort (and money) on skincare, leaving my hair and scalp to fend for themselves with whatever supermarket products happen to be lying around in my bathroom. Please, feel free to judge.
But there’s a reason behind this neglect. As a beauty writer with over a decade of experience testing thousands of haircare products, I’ve yet to find a shampoo, conditioner or treatment that truly wows me enough to repurchase or recommend. Whether it’s a premium product with a hefty price tag or one with glowing five-star reviews, nothing has ever left me impressed … until I discovered Unwritten Hair’s So Sublime Hydro Repair Serum.
To call this just another hair treatment product would be a disservice. This scientifically advanced formula is marketed as a hair serum – yes, like a serum for your face but designed for your locks – which promises to transform dull, lacklustre hair into soft, radiant tresses in mere hours. The best part? It’s priced at an affordable $39.95 for a 100ml bottle.
Unwritten So Sublime! Hydro Repair Serum 100ml, $39.95 at Unwritten Hair
Unwritten So Sublime Hydro Repair Serum
HOW WE TESTED UNWRITTEN HAIR SO SUBLIME HYDRO REPAIR SERUM
To help you determine if Unwritten Hair’s So Sublime Hydro Repair Serum is really worth your money, I put it to the test for four weeks over the Australian summer.
I used it alongside Unwritten Hair’s Bliss Out Vitamin Shampoo and Conditioner, which are available separately or as part of the cost-effective Hydration Repair Trio bundle ($109.95, saving $17.90).
During this period, I applied the serum after washing my hair, used it as a heat protectant before styling and even relied on it as a refresher prior to heading to the beach or pool.
WHAT IS THE UNWRITTEN HAIR SO SUBLIME HYDRO REPAIR SERUM?
The So Sublime is Unwritten Hair’s flagship product, which is designed to “rehydrate your hair by 97 per cent in just two hours”.
If you’re unfamiliar with Unwritten Hair, you’re not alone — in fact, it’s all part of the brand’s advertising strategy.
Unwritten Hair, a proudly Australian brand, was founded by four haircare industry veterans with over 50 years of combined experience. Their mission? To create a concise range of products blending cutting-edge hair science with native Australian ingredients — without the marketing fluff or exaggerated claims.
All Unwritten Hair products are manufactured and bottled in Sydney, developed by local chemists in collaboration with real hairdressers.
In fact, the brand is so confident their products work wonders that they offer a 30-day money-back guarantee. This means in the highly unlikely event you find yourself dissatisfied with your items, you can literally send them back within 30 days of receiving your goods for a full refund.
The quality of the formulas isn’t the only thing that has put Unwritten on the hair health map — it’s the brand’s dedication to sustainability that has earned the trust of thousands of customers. The entire range is PeTa-certified vegan and animal-cruelty-free, carbon neutral and packaged in bottles made from 30 per cent recycled plastic that’s 100 per cent recyclable. This ensures you can feel good about looking good.
WHAT DOES THE HAIR SERUM DO?
No matter your hair type – fine, frizzy or thick – the So Sublime Hydro Repair Serum is designed to hydrate deeply, even the driest, most damaged locks, within two hours.
Its lightweight, vegan formula is packed with powerhouse hydrators like hyaluronic acid, trehalose, glycerin and urea. But while incredibly moisturising, it’s far from being thick and heavy — thanks to the addition of natural bio-polymers such as alginate and pullulan, the serum delivers intense moisture without weighing hair down — making it a game-changer for fine hair and extensions.
Beyond hydration, the serum offers protection against UV rays, heat up to 270 degrees Celcius and environmental aggressors like salt and chlorine. It helps prevent moisture loss, colour fade and damage caused by styling tools or outdoor exposure. That means it’s the perfect product to reach for before using styling tools or prior to swimming and spending time outdoors under the sun.
HOW TO APPLY THE UNWRITTEN HAIR SO SUBLIME HYDRO REPAIR SERUM
Start with shampooing and conditioning your hair (for best results, use products from the Unwritten Hair range, which you can check out here). Depending on your hair length and thickness, you want to apply two to four pumps into your hand and work it through from your mid-lengths to ends. You can then proceed with blow-drying and styling your hair, without worrying about damaging your precious locks.
You can also use the serum on dry hair as a refresher for added hydration or protection throughout the day.
THE SO SUBLIME HYDRO REPAIR SERUM: MY RESULTS
My hair is fine, straight and frequently exposed to damage from daily heat styling and regular colouring. Add to that my sensitive scalp, which reacts poorly to new products and weather extremes, and you’ve got a recipe for flat, dry-looking locks that require high maintenance — and yet, barely receive it.
But despite all the challenges the So Sublime hair serum had to work through, it did pull through — even from the first application.
It was quite amazing how it tamed post-shower frizz, absorbed quickly and left no heavy or greasy residue (a massive tick of approval). A few hours later, my hair felt noticeably softer, and by the fourth use, the transformation was undeniable.
The inclusion of hyaluronic acid worked wonders for my scalp, alleviating itchiness and dryness throughout the trial period. The serum’s subtle scent was another bonus, and its lightweight texture meant a little went a long way — three pumps was more than enough to cover my hair from roots to ends.
Most impressive was how well my hair held up during long days under the harsh Aussie sun. Even after frequent trips to the beach and pool, my locks remained shiny, soft and healthy — all thanks to this serum.
WHAT THE REVIEWS SAY
I’m not the only one impressed by the results from Unwritten Hair’s So Sublime Hydro Repair Serum. The single product has garnered hundreds of five-star reviews on their website, which all rave about the results.
“I can’t believe how much this has changed my hair,” exclaimed one five-star review. “For someone that swims in the ocean and is outdoors a lot, this serum has transformed my hair BIG time. I am now able to brush my hair after surfing, extend the amount of time between hair washes and it just feels silky smooth. It’s the best. My scalp is also not as dry when usually this time of the hair (winter) it really dries out. So thankful to have found this product.”
A second person wrote: “Fantastic. Noticed the difference straight away. Only used it twice. Can’t wait to see what it looks like in a couple of weeks.”
Many others commented on their amazement with the product’s non-greasy formula.
“A lot of serums I use end up making my hair feel oily but the texture is easily absorbed and settles “the freshly washed frizz” I often get,” a satisfied customer said. “Love how smooth and silky it makes my hair look and feel!”
Another person added: “So Sublime! Hydro Repair Serum is my go-to for luscious locks. It’s a hair game-changer – lightweight, non-greasy, and oh-so-nourishing. My hair feels softer and more manageable after just a few uses. Plus, it smells amazing!”
A third simply said: “It’s great serum for daily use, and doesn't build up or look oily.”
IS UNWRITTEN HAIR’S SO SUBLIME HYDRO REPAIR SERUM WORTH IT?
For $39.95 per pop, this hair serum is a no-brainer. That’s more affordable than most hair lotions, creams, masks and oils you can find at your local supermarket or drugstore.
In fact, I’m a full-blown So Sublime convert I would recommend purchasing the So Sublime Duo for $69.95, which means you can snag two 100ml bottles for a discount of $9.95. Every dollar counts, right? What’s more, you can score a 15 per cent discount on your first order when you subscribe to Unwritten Hair’s newsletter. Plus, the company offers same-day dispatch (if you place your order before 11am) and a 30-day money-back guarantee, so adding the serum – along with other Unwritten Hair products – to cart should come with absolutely zero hesitation.
I do have to admit that combining the serum with the Bliss Out Shampoo and Conditioner definitely contributed to the speed of the results as opposed to just using a regular shampoo and conditioner. If your budget allows, I would advise considering the Hydration Repair Trio for $109.95 — this comes with the Bliss Out Hydro Repair Shampoo and Conditioner and the So Sublime Hydro Repair Serum, which are all designed to transform your hair within two to four washes.
There are other bundles available, like the Vitamin Repair Trio ($109.95), the Blonde Bombshell Collection ($145.95), the Roots To Ends Trio ($123.95), the Styling Trio ($92.50) and the Anti-Frizz Styling Duo ($69.95), just to name a few.
All in all, I’m officially a convert after four weeks of consistent use with the hair serum. Unwritten Hair has proven that investing in scientifically backed, Australian-made haircare products can make all the difference.
To discover the full haircare range, head online to Unwritten Hair.
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