One of the biggest hair trends of 2023 isn’t a celebrity-inspired cut or TikTok-famous colour – beauty buffs eager to make more sustainable choices are lathering up with solid shampoo bars instead.

Starting out as a niche product for eco enthusiasts, shampoo bars have gone well and truly mainstream in recent years, with beauty behemoths like Aussie and Garnier, as well as salon brands such as Percy & Reed, launching their own.

Cosmetics company Lush reports customers have bought 76% more shampoo bars than bottles of liquid shampoo so far this year.

According to Lush, shampoo bars were invented in 1987 by the brand’s co-founder Mo Constantine and cosmetic chemist Stan Krysztal for Cosmetics to Go (the former mail order company owned by the founders of Lush).

They’ve come a long way since then, which explains why even skeptics are now being converted to plastic-free haircare.

Here are six reasons you should think about trying a solid shampoo…

1. Less plastic packaging

New research published in journal Plos One reveals the staggering level of plastic pollution, with 170 trillion particles floating in the world’s oceans.

“The worldwide plastic waste issue is obvious,” says Rebecca Mapes, CEO of Winden, a hair accessories brand that recently branched out with the launch of its Signature Solid Shampoo.

“What’s really alarming to me is the cosmetics industry contributes so heavily to that waste, and only 9% of all plastic is recycled.”

Recognising the climate crisis can be paralysing for shoppers, she says: “Solid shampoo is one way we as consumers can easily change our habits, without sacrificing the quality of our haircare products.”

Megan Curtin, senior manager of education at hair brand Briogeo, agrees: “Many shampoo bars provide the equivalent number of hair washes as two shampoo bottles, which is a major reduction in plastic waste.”

2. Reduces water use and carbon emissions

“Good solid shampoo is simply liquid shampoo without the water,” Mapes explains.

“Most consumers already have access to water in their homes, and shipping water around the globe just isn’t necessary anymore.”

Plus, the heavier the products, the more carbon emissions result from transporting them.

3. Solid shampoo is just as good as liquid

While they may look like a bar of soap, solid shampoos have more in common with their liquid counterparts.

“The quality is generally the same as traditional shampoos, meaning they won’t strip your hair,” Curtin says.

“Most shampoo bars are formulated without harsh surfactants and [are] infused with hydrating ingredients to provide the kind of slip we’re used to with liquid shampoos.”

With a huge range available in stores and online, there’s a solid shampoo whatever your hair type or concern.

4. Cut down on clutter

“There was a time when choosing sustainable options meant you would have to sacrifice aesthetics, thankfully that just isn’t true anymore,” says Mapes.

Shampoo bars – and their aesthetically pleasing cases – take up less space and mean you don’t end up with a graveyard of almost-empty bottles clogging up your bathroom.

Investing in a case for your shampoo bar will help prevent it from melting away in your shower.

5. Convenient for travel

“Shampoo bars are the ultimate on-the-go product, especially with the right travel case,” says Curtin.

“They’re compact and fit easily into the smallest toiletry bags – most are sized to fit nicely in the palm of your hand.”

Some brands even make smaller versions especially for packing in your luggage or cabin bag.

“The best part?” Curtin adds, “Since they’re solid bars, they are always airport-friendly – no worry about liquids here!”

6. Long-lasting and affordable

How many times have you accidentally squeezed way too much shampoo into your palm, only to watch it drip to the shower floor and run down the plughole?

There’s no such problem with shampoo bars that can be lathered directly onto wet hair, plus you won’t need to use as much product each time – and most are priced under £10.

“Our solid shampoo bars are much more concentrated than liquid shampoo, meaning they can last up to 80 washes,” says Rae Stanton-Smithson, Earthcare communications lead at Lush.

“Not only does this eliminate plastic bottle waste, but potentially saves our customers having to purchase up to three 200ml liquid bottles of shampoo.”

Raise the bar: Plastic-free shampoos for every hair type

Aussie Koality Moisture Vegan Solid Shampoo Bar, £6.66 (was £9.99), Boots

Winden Petite Signature Solid Shampoo, £6.50

Lush Seanik Shampoo Bar, £9

Wild Coconut & Vanilla Shampoo, £8.50

Garnier Ultimate Blends Honey Treasures Strengthening Shampoo Bar for Damaged Hair, £7.99, Boots

Grüum Hår Zero Plastic Anti-Dandruff Shampoo Bar, £8, LookFantastic

Percy and Reed All Lathered Up Shampoo Bar, £12

Eco Warrior Sensitive Scalp Shampoo Bar, £5.50, Sainsbury’s

Brigeo Be Gentle, Be Kind 3-in-1 Cleansing Bar for Hair, Face + Body, £25.99

WeDo/ Professional Shampoo Bar and Holder Bundle, £24.90, LookFantastic