Marks and Spencer shoppers are snapping up a beauty serum that has been praised as ‘a neck lift in a bottle’. The product is currently already discounted from £45 to £36, but there’s a way to get it for even cheaper.

Here’s how it works. For new members of TopCashback and all customers of M&S, shoppers can grab the This Works Perfect Cleavage & Neck Serum (150ml) for £20.70 after cashback. For existing members of TopCashback and all customers of M&S, however, it’s £35.70 after cashback. The price calculated includes free click and collect, while standard delivery is from £3.99.

The This Works Perfect Cleavage & Neck Serum (150ml) is described as a ‘nourishing serum’ that has been formulated specifically for the skin on the cleavage and neck. It is also enriched with marine algae, hyaluronic acid and botanical oils.

Hyaluronic acid helps to moisturise and plump the skin for a softer, smoother result, while larch extract is said to have an instant tightening and firming effect. There’s also the vitamin C-rich marine algae, which helps to brighten and even the skin. To use the serum, shoppers should massage the product into the cleavage and neck daily.

For an alternative, however, there’s this No7 Future Renew Neck & Décolletage Serum (50ml) for £38.65, down from £42.95. The brand claims this product is ‘proven to reverse visible signs of skin damage in these delicate areas’.

Or at LookFantastic, there’s the Medicube Triple Collagen Serum 4.0 (55ml) for £18.40, down from £23. This is described as a milky serum that nourishes and smooths visible fine lines and offers ‘a glass skin glow’.

But returning to the This Works Perfect Cleavage & Neck Serum (150ml), shoppers have left many positive reviews on M&S’ site. One said: “It’s like a neck lift in a bottle! My skin looks so much smoother and firmer after just a few weeks.”

A second said: “This does work and smells divine when I have used it on my mature skin.” While a third wrote: “This is lovely to use, absorbs beautifully and gives great results.”

Others weren’t totally satisfied, as another said: “I bought this out of curiosity to see whether it would do any good. So far, after a couple of weeks, I haven’t noticed any difference, but it goes on smoothly and has a pleasant herbal smell. I may yet see a smoother neck and cleavage!!”

Someone else said: “Lovely product. It is light and smoothes skin effortlessly. Bought when on offer as a bit pricey.”