This £79 cellulite cream promises firmer skin in four weeks, and it's sold out five times to prove it

Body skincare has always felt like the poor relation to our face routines. We'll happily layer up our best retinol serums and vitamin C serums for our complexions, then reach for whichever moisturiser is closest to hand for everything below the neck - even though crepiness, stretch marks and lost firmness bother most of us just as much there as they do on our faces. Every so often, though, a product comes along that changes the way we think about that gap.

Right now, that product is Murad's Retinal ReSculpt Body Treatment. Since it launched, the £79 cream has sold out five times, with Murad's global data showing one jar selling every nine minutes - and it's even picked up several beauty awards since its launch, proof that it's not just marketing spin.

Part of the appeal is that it's still the only retinal (not retinol) body treatment on the market, tackling cellulite, stretch marks, crepey skin and sagging in as little as four weeks. But what actually is retinal, and is it worth swapping into your body care routine? Here's everything you need to know.

Retinal vs retinol: what's the difference?

If you're a skincare regular, you'll know retinol well - it's one of the most researched anti-ageing ingredients around, working by speeding up cell turnover and boosting collagen production. Retinal (short for retinaldehyde) is a step further along in the vitamin A conversion process, which means skin can use it more directly and, in theory, see results faster than with retinol.

In Murad's Retinal ReSculpt Body Treatment, the retinal is encapsulated - essentially wrapped in a delivery system designed to release it gradually and reduce the irritation retinoids are often known for. That's paired with an "Exerkine-inspired" complex of milk thistle and bearberry extract, ingredients chosen to echo the compounds the body naturally releases during exercise, plus shea butter, avocado extract and squalane for hydration. Unlike some retinol formulas, there's no percentage strength to work out or build up gradually - you simply apply it at night as part of your normal routine.

Does it actually work?

With a stream of five-star reviews, it's safe to say users are loving it. "This cream is worth every penny," wrote one user. "It works. My skin has never looked better. And I can see such a difference on my stomach."

"Have only been using for a week but already noticing a difference on the crepey skin on my arms," wrote another, while one stated, "Simply brilliant". Even experts across the industry have been raving about it.

That said, it's worth setting expectations. Retinal, like any retinoid, works gradually and won't dramatically reshape the body or eliminate cellulite and loose skin altogether - it's a texture-and-firmness treatment, not a substitute for professional body treatments if that's what you're after. Anyone using it should also apply SPF over treated areas during the day, as with any vitamin A product.

Who should try it - and how to use it

Murad recommends focusing application on the areas prone to crepiness and dimpling: thighs, chest, elbows, knees, the backs of the arms and the abdomen. It's designed for nightly use, though anyone with sensitive skin might want to start at two to three times a week and build up.

At £79 for 148ml, it isn't cheap for a body cream, but a little goes a long way, and Murad currently offers free standard shipping on orders over £30, plus two complimentary deluxe samples with every order from murad.co.uk.