Firmness
Firm
Type
Pocket Spring
Depth (cm)
25
Number of Layers
7
Trial Period (nights)
100
Warranty (years)
5
Price Range
£549 to £1,089
Best Sleeping Position(s)
Certifications
Assessed from the specification published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
You get a lot of traditional craftsmanship for the money here. The 1200 pocket springs adjust to your movement individually, which means better motion isolation than an open coil design, and the outer rows use a firmer gauge with a rod edge, so you can sit or sleep near the side without feeling like you'll roll off. The eOlus fibres are made from recycled materials and promote airflow to dispel heat, helpful if you're a warm sleeper. Hypnos is a National Bed Federation Approved Brand and the mattress conforms to BS7177: 2008 for fire resistance. Yes, it's firm, but for heavier sleepers or anyone whose current mattress feels like a hammock, that's the point.
Key Features & what's inside
- Cover. A soft to touch Belgian damask cover, which gives a more traditional, upholstered feel than a knitted stretch fabric.
- Comfort layer. A blend of cotton and polyester that combines their comforting properties with increased breathability and moisture wicking. In practice, that means less clamminess on warmer nights.
- eOlus fibres. Hypnos' exclusive eOlus fibres are made from recycled materials and spun into breathable fibres that promote airflow to dispel heat. They also contribute to the secure, firmer feel this mattress is built around.
- Soft White Fibres. Soft synthetic fillings that create a cosy feel while staying durable and resilient. They're designed to maintain their shape rather than compressing into dips over time.
- Support pad. A dual density polyester pad that protects the spring unit and encourages equal weight distribution, which means the springs beneath wear evenly.
- Spring core. 1200 ReActive springs, each sitting in its own fabric pocket to increase responsiveness and isolate movement. You should feel less of a partner shifting about on the other side.
- Edge support. The outer rows of springs use a firmer gauge, reinforced with a durable rod edge. That gives you a sturdier perimeter for sitting on the edge and makes the full sleeping surface usable.
Layer details from mattressonline.co.uk product page, September 2026.
Who's it NOT for?
This isn't the one if you like a soft, sink-in feel. It's a firm mattress, and across owner reviews some found it firmer than expected, so lightweight side sleepers may find it puts a little too much pressure on hips and shoulders. There's also no memory foam, so don't expect that slow, contouring hug.
Hypnos Cawthorne Support Mattress
View all mattresses
Is the Hypnos Cawthorne Support mattress firm?
Yes, it's rated firm. The eOlus fibre layer is designed to give a secure, firmer feel, and owner reviews back this up, with some customers finding it firmer than they expected. If you prefer a medium or softer surface, this probably isn't the right pick.
How many springs does the Hypnos Cawthorne Support have?
It has 1200 ReActive pocket springs. Each spring sits in its own fabric pocket, which means it responds to your movement individually and limits how much motion travels across the bed. The outer rows use a firmer gauge, reinforced with a rod edge, for sturdier edge support.
Does the Hypnos Cawthorne Support come with a trial?
Mattress Online lists a 100-night trial with this mattress. That's the retailer's own offer rather than a Hypnos guarantee, and it requires purchasing a mattress protector from MattressOnline to be eligible, so check the terms before you buy.
What sizes is the Hypnos Cawthorne Support available in?
It comes in UK Single, Small Double, Double, King, Super King and Emperor, plus EU Double and EU King. Prices range from £549 to £1,089 depending on size, and the mattress is 25cm deep.
Is the Hypnos Cawthorne Support good for hot sleepers?
It should cope reasonably well. The cotton and polyester comfort layer offers breathability and moisture wicking, and the recycled eOlus fibres promote airflow to dispel heat. There's no foam to trap warmth, which tends to help spring mattresses sleep cooler.
Couldn't find an answer to your question? Send us a message