Garnier Olia 5.0 Brown: 28,000 Ratings, a 60% Oil Formula, and a Packaging Scandal

The Packaging Problem Nobody Warned You About

We're leading with this because it dominates the recent review landscape and you need to know about it before anything else. A significant chunk of one-star reviews aren't complaining about the hair dye at all. They're reporting that their boxes arrived with instructions printed entirely in a foreign language, no English leaflet in sight.

Christine Winter gave it one star and wrote: "Nothing is in English, so thank god I already know what I am doing." She's not alone. Multiple buyers have reported the same issue, and it gets worse. Nick Hathaway ordered three boxes and found that "all of them are of the old design and had been previously opened and the instructions removed."

This points to a supply chain issue with certain Amazon sellers shipping grey market or old stock rather than official UK inventory. The dye inside is the same Garnier formula, but the packaging and documentation are clearly not intended for the UK market. If you're a first-time user, this is a real problem - you'd be colouring your hair with no guidance on timing or mixing.

Our advice: buy from Amazon directly (check the "Sold by" line), and if you're new to box dye, bookmark a YouTube tutorial as backup. If your box arrives with foreign-language instructions, don't hesitate to return it.

What Makes the Oil Formula Different

Now, the actual product. Garnier Olia's entire pitch rests on replacing ammonia with a 60% oil-powered delivery system. Traditional permanent dyes use ammonia to swell the hair shaft and force colour in. Olia instead uses a blend of Natural Flower Seed oils - Sunflower, Meadowfoam, Camellia, and Passionfruit - to carry the colour pigments into the hair.

The practical difference? No ammonia smell during application (every positive reviewer mentions this), and hair that feels noticeably softer after colouring rather than stripped and dry. The formula is also vegan and comes with a silicone-free conditioner, which is a relatively new addition to the Olia line.

Garnier claims 3x more shine compared to uncoloured hair, which is a bold statement. But based on what reviewers are reporting, the shine claim holds up better than most marketing promises. One reviewer, Brenhines y Cathod, wrote that she gets "often complimented on my hair colour" and called it a "bright, stunning colour."

How the Oil Delivery System Actually Works

The technology behind Olia is worth understanding because it explains both why people love the results and why some have trouble with it. The Oil Delivery System (ODS) uses the oil blend as a carrier to transport colour deep into the hair fibre without needing harsh chemicals to force the cuticle open. The oils naturally help the pigment penetrate, which is why the formula can skip ammonia entirely.

This approach also means the colouring process is gentler on your scalp. Several reviewers specifically mentioned no burning or irritation, which is a common complaint with traditional ammonia-based dyes. That said, a small number of reviewers did report allergic reactions, so the standard 48-hour patch test is non-negotiable. Every box dye carries this risk, oil-based or not.

Grey Coverage and Colour Accuracy: Where Reviewers Disagree

This is where the reviews split in an interesting way, and it has nothing to do with dodgy packaging.

On grey coverage, the verdict is almost unanimously positive. Joana Santos, a repeat buyer, wrote: "I use this shade regularly to touch up my roots, especially to cover greys, and it has worked really well for me." Garnier claims 100% grey coverage, and the reviewers back that up consistently. If covering greys is your primary goal, Olia 5.0 Brown delivers.

Colour accuracy is more contentious. Many reviewers say the shade is true to the box - a rich, natural-looking medium brown. But others found it came out darker than expected, particularly on lighter hair. This is fairly standard for permanent dyes in the brown range; the starting colour of your hair always affects the final result, and box images can only show one possible outcome.

There's also a specific warning for anyone with bleached or previously lightened hair: several reviewers reported that the colour fades much faster on pre-lightened hair. If that's your situation, you may find yourself reapplying sooner than the typical 8-week cycle.

The Salon Switchers: First-Time Box Dye Users Weigh In

Some of the most convincing reviews come from people who switched from salon colouring to Olia for the first time. One Amazon customer gave it five stars (with 8 helpful votes) and wrote: "Brilliant, first ever time using a box dye, I've always gone to the salon... This has turned out perfect."

That's a powerful endorsement. Salon-to-box converts are typically the hardest audience to please because they're comparing against professional results. The fact that multiple first-timers reported being impressed suggests the oil formula produces a quality of finish that most drugstore dyes can't match.

The kit itself is straightforward: a developer cream, colour cream, silicone-free after-colour conditioner, gloves, and an instruction leaflet (assuming you get the English one). Several reviewers singled out the included conditioner as surprisingly good, leaving hair soft and shiny rather than the straw-like texture you sometimes get after permanent colour.

A practical note that comes up repeatedly: one box is enough for short to medium-length hair. If your hair is past your shoulders, buy two boxes. Multiple reviewers learned this the hard way.

The Ethics Angle: Vegan, Cruelty-Free, Less Plastic

Garnier has pushed hard on the ethical credentials of the updated Olia formula. It's certified cruelty-free (approved by Cruelty Free International), the formula is vegan, and the packaging uses less plastic than previous versions. The conditioner is silicone-free too, which matters if you follow a curly girl method or just prefer to avoid silicone buildup.

These aren't just marketing badges. For the growing number of shoppers who factor ethics into their purchasing decisions, Olia checks every box that matters in the hair colour category. At £7.07, you're getting a vegan, cruelty-free permanent dye that actually performs - that combination is still surprisingly rare at this price point.

The Improved Formula: What Changed

The current version of Olia 5.0 Brown runs under Garnier's "New Improved Formula" banner, which highlights the three big changes: no ammonia, no silicone, and a vegan formulation. The silicone-free aspect is the newest update - previous Olia versions included silicone in the conditioner, which could create buildup over repeated use.

Some reviewers did note that the oil-based formula can leave hair feeling slightly greasy in the first wash or two after application. This is a trade-off of the high oil content and tends to settle after the second wash. If you have naturally oily hair, you might want to do an extra rinse.

The colour longevity is generally rated well for home dye, with most reviewers reporting the shade holding strong for 6-8 weeks before needing a root touch-up. That's roughly in line with what you'd expect from a quality permanent colour at any price.

So Who Should Buy It, and Who Should Be Careful?

Garnier Olia 5.0 Brown is a strong choice if you're looking for a reliable, ammonia-free permanent colour that covers greys and leaves your hair in better condition than most box dyes. The oil formula produces results that multiple salon switchers have called impressive, and at £7.07 it's roughly a tenth of what you'd pay for a full salon colour.

It's particularly well-suited to anyone with a sensitive scalp. The ammonia-free formula and gentle oil delivery system mean less irritation during application, and the aftercare conditioner is noticeably better than the typical sachet you get with budget dyes.

Be cautious if: your hair is bleached or heavily lightened (colour may fade faster), you need more than one box (budget for two if your hair is past shoulder length), or you're buying from a third-party seller on Amazon (check for English instructions and intact packaging before you start mixing).

The recent rating average of 3.40 is misleading. Strip out the reviews complaining about foreign-language instructions and tampered packaging - issues with the seller, not the product - and the actual product satisfaction rate is comfortably above 4 stars. With 28,345 total ratings and a #4 ranking in Permanent Hair Colour, Olia has built a loyal repeat-purchase following for good reason. Mrs Nicola Hatton summed it up neatly: "Gorgeous coverage and shiny results after application. Easy to use and good value for money."