Officially the Labor Day mattress sales are just a few days away, but in actual fact you’ll find that pretty much every sleep brand has fired up its Labor Day sales by now. So if you’re all set to buy one of the best mattresses on Labor Day, you could do well by ordering now rather than waiting until the day itself.
Most sleep brands have mattress sales running just about every day of the year, and this means they’re generally well prepared for sales events such as Labor Day. So they get their deals up well in advanced, and in most cases the prices you see now will be the ones you’ll pay on Labor Day. There may be a few instances of brands running flash sales with slightly increased discounts on Labor Day itself – Casper in particular has rolled out a handful of these during recent sales events – but on the whole, nearly all the prices you see here are the ones you’ll pay on Labor Day.
We’ve listed some of the top current deals for you, and as we get closer to Labor Day itself we’ll be updating this page with the best bargains as soon as we find them, so whether you’re after the best memory foam mattress, the best hybrid mattress or simply the best king size mattress, you should be able to find a fine discount. We’ve also included some handy info about the Labor Day mattress sales so that you can get properly prepared for the main event; for now, though, let’s get to the best mattress discounts available today.
Labor Day mattress sales 2023: quick links
Editor’s choice – Saatva: $200 to $500 off orders over $1,000Budget pick – Nectar: 33% off all mattressesDreamCloud: 40% off all mattressesAmerisleep: $450 off any mattress with promo code AS450Avocado: save 10% on green and vegan mattresses with code LABORDAYAwara: $400 off any mattressBear Mattress: 35% off sitewide + $400 of free sleep accessoriesBig Fig: save $400 with code LABORDAYBirch Living: 25% off mattresses + 2 free eco-rest pillowsBrooklyn Bedding: 25% off sitewide with code LABORDAY25Casper: up to 20% off sitewideCocoon by Sealy: save 35% on cooling mattresses + free pillows and sheetsGhostbed: 50% off the GhostBed Luxe + 35% off other bedsHelix: 25% off sitewide + 2 free pillowsLayla: save up to $200 on mattresses + two free pillowsNolah: up to $1,200 off mattresses + two free pillowsTempur-Pedic: save up to $700 on select adjustable mattress sets
The best early Labor Day mattress sales
1. Saatva Classic: was $1,095 now from $895 at Saatva
Editor’s choice – Saatva is taking between $200 and $500 off orders over $1,000 in its Labor Day sale. That means you can save really big on our top mattress recommendation: the Saatva Classic, which sits at number one in our best mattress guide. We found this mattress delivered superb comfort, support and durability for less than its luxury rivals when we tested it. With this deal it now costs $1,695 for a queen (down from $1,995), and you’ll get a lifetime warranty, plus a full year to trial it.View Deal
2. The DreamCloud Mattress: was $839 now from $499 at DreamCloud
Luxury hybrid – You’ve just missed a DreamCloud flash sale that delivered a 50% price cut, and now the DreamCloud Labor Day sale knocks the company’s usual 40% off the price, which means a queen size will cost you $799. This medium-firm mattress is one of America’s top beds for back pain, with dedicated lumbar support to ease aches and pains. In our DreamCloud Mattress review we also recommend it as a great choice for hot sleepers, as it sleeps cooler than many other hybrids we’ve tested. There’s a 365-night risk-free trial too, plus a forever warranty.View Deal
3. Nectar Memory Foam Mattress: was $649 now from $399 at Nectar
Best budget – The Nectar mattress is a superb lower-mid-range memory foam mattress and there’s 33% off in Nectar’s current sale. We think it’s the best budget mattress you can buy, and one of the best memory foam mattresses for anyone on a tighter budget. In our Nectar Mattress review we found it to be particularly comfortable for side and back sleeping, with good pressure relief and temperature regulation. However, if you’re a particularly hot sleeper, choose the Saatva above or the DreamCloud below, as these offer better temperature regulation properties.View Deal
4. Helix Midnight Mattress: from $936.30 $702.20 + 2 free pillows at Helix
Best mattress for side sleepers – In last year’s Labor Day mattress sale Helix was running tiered discount, but this year it appears to be sticking to a straight percentage reduction. which is a bit of relief. Right now there’s 25% off, which knocks the price of a queen Helix Midnight to $999, which is as good as it gets. Two Dream pillows are included for free, as well. If you’re a front sleeper, you might need more support, though, in which case check out the Saatva Classic, or if you want to stick with Helix, the Helix Dusk. View Deal
5. Cocoon by Sealy Chill Memory Foam mattress: was $619 now from $399 + free bedding at Cocoon by Sealy
Affordable cooling mattress – If you tend to sleep hot, check out the Cocoon by Sealy Chill. This memory foam mattress is designed to keep you cool at night, thanks in part to a cover made with phase-change material designed to regulate your temperature as you sleep. There’s 35% off right now, with some free pillows and sheets thrown, and the MSRP has actually come down since last year, so you’ll pay less this Labor Day than you would have in 2022. You can pick up a queen for $699 (was $1,079), and score $179 in free bedding, too. It’s a great option if you suffer with back pain, but side sleepers may find it too firm.View Deal
6. GhostBed Luxe Cooling Mattress: was $2,595 now from $1,298 + 2 free pillows at GhostBed
Best cooling mattress – The ‘coolest bed in the world’ is by no means a cheap mattress, and the price has gone up a bit since 2022. But with 50% off it’s pretty well priced for what you get: a queen is now $1,598 (down from $3,195), which is quite a bargain. Also included with purchase are two free cooling pillows (worth $219) plus 10 years of accident protection from stains and spills. The standard 25-year warranty applies, and you get 101 nights to trial it. View Deal
7. Awara Natural Hybrid Mattress: was $1,099 now from $699 at Awara
Best organic mattress – Organic mattresses aren’t cheap, but this is a good saving on a popular model by the same company that owns Nectar and DreamCloud (hence the excellent 1-year trial and Forever Warranty). The Awara is on the firmer side, which makes it a great choice for back or stomach sleepers in need of some extra support. There’s $400 off the full range in the Awara sale. View Deal
8. Birch Natural Mattress: was $1,498.80 now from $1,124.10 plus 2 free pillows at Birch Living
25% off – The Birch Labor Day sale takes 25% off all mattresses. That means you can bring home a queen-sized Birch Natural Mattress for $1,592.80, which is a solid price for one of the best organic mattresses. A layer of Talalay latex plus a support layer of individually-wrapped steel coils means most sleepers will find comfort and support. A 100-night trial and 25-year warranty apply.View Deal
9. Purple Plus Mattress: was $1,495 now from $1,195 at Purple
Save $300 – The Purple Labor Day sale gets you $300 off the Purple Plus in all sizes. Where this mattress shines is in its pressure relieving properties, but it’s also a good choice if you want a cooling mattress. This mattress is medium in firmness, with the GelFlex grid plus an added layer of comfort foam not present in the original Purple mattress. A queen size will cost you $1,595 (was $1,895). Other Purple mattresses are on sale for $200 to $500 off, and you can get further discounts on most models by adding a smart base. View Deal
10. Avocado Green Mattress: was $1,399 now from $1,259.10 at Avocado
Best organic mattress – Avocado is taking 10% off most of its mattresses in its Labor Day sale, which means that you can save up to $259.90 on the Avocado Green Mattress. It’s available in gentle-firm and medium-firm feels, and is made using organic materials. You can bring home a queen size mattress for $1,799.10 (was $1,999) – which is a decent deal, considering you also get a 1-year trial plus a 25-year warranty with your purchase. View Deal
Labor Day mattress sales: Memory foam
Nectar Memory Foam Mattress: was $599 now from $359 at Nectar
Great price – Nectar Labor Day sale takes 33% off everything. That brings the price of a queen down to $699 (from $1,049), and while this is actually standard Nectar pricing, it’s well below the average price you’d pay for this size mattress at most other brands. The low price doesn’t mean you compromise on quality, though; we sang its praises in our Nectar Mattress review for exceptional pressure relief and good temperature regulation. You get a full year to try it at home, as well, with an industry-leading forever warranty to back your purchase.View Deal
Saatva Loom & Leaf: was $1,295 now from $1,095 at Saatva
Up to $350 off – This luxurious foam-only bed from Saatva delivers top-notch pressure relief for back ache and sore joints, and its gel-infused foam stops it getting too warm. It’s a pricier memory foam mattress, but it includes various different foams, with the top one infused with gel to help keep it cool overnight. We think this is a good choice if you suffer from back pain, as it’s firmer than many memory foam mattresses, to help keep your spine in correct alignment. The Saatva Labor Day sale takes up to $350 off the Loom & Leaf, getting you a queen size for $2,095.View Deal
Bear Original Mattress: was $748 now from $487 + free accessories at Bear Mattress
35% discount – Bear Mattress has a 35% off sitewide sale Labor Day, which is the same discount it was running back on the 4th of July. The Bear Original is the brand’s most affordable cooling mattress, and this is a great time to grab one. The price of a queen is down from $998 to $649, while a twin is just $487. Add to that a free sleep bundle including pillows, sheet set and mattress protector, and you have an outstanding value for money. Memory foam mattresses are prone for trapping heat, but the Bear Original’s cooling graphite-gel memory foam will keep you comfortable and well-supported all night long. View Deal
Purple Plus Mattress: was $1,495 now from $1,195 at Purple
$300 off – There are discounts on all Purple’s mattresses in its Labor Day sale, and because it’s a straight $300 off across its entire range, the biggest percentage savings are to be had on its Essential collection. We’d direct you towards the Purple Plus; this memory foam mattress adds something extra in the form of Purple’s GelFlex grid that cradles pressure points and promotes better airflow. It also has an additional layer of comfort foam not present in the original Purple mattress. Right now a queen size will cost you $1,595; you can add extra savings by getting a base to go with your new mattress.View Deal
Siena Memory Foam Mattress: was $499 now from $199 at Siena Sleep
Save $300 – The medium-firm Siena Memory Foam Mattress is a good budget option for your bedroom or for upgrading a guest room. It’s 10 inches tall, an average height for budget boxed mattresses, and uses gel memory foam to boost airflow. There’s also motion-reducing foam to isolate motion from your partner during sleep, with contouring memory foam to give you both a relaxing, body-hug feel. A queen size is down to $399 (was $699) in this year’s Siena Labor Day mattress sale; you’ll get 180 nights to trial it too, which is the same trial length as luxury brands such as Saatva. View Deal
Labor Day mattress sales: Hybrid
Nolah Evolution 15″: was $1,499 now from $999 at Nolah
Up to $1,200 off + free pillows – The Nolah Labor Day sale is well worth checking out, with prices lower than on 4th of July as well as two free Nolah Squishy pillows included to sweeten the deal. This means you can get its most popular mattress, the luxurious Nolah Evolution 15″, for $1,699 in a queen size ($50 cheaper than 4th of July), and enjoy its impressive pressure relief and spinal alignment at a great price.View Deal
Casper Original Hybrid: was $1,095 now from $876 at Casper
20% reduction – There’s up to 20% off most mattresses at Casper for Labor Day, and the Casper Original Hybrid gets the full 20% off. That’s a great discount on a quality hybrid mattress that delivers a medium-firm feel, cradling support and low motion transfer. With this limited-time deal you can get a queen size for $1,196; we’ve noted in the past that Casper can drop bigger flash discounts on sales event days themselves, so it might be worth holding out for a lower price on Labor Day.
Leesa Legend Hybrid Mattress: was $1,999 now from $1,599 at Leesa
Save up to $700 – There are savings across Leesa’s full range for Labor Day, but the biggest price drop is on the luxurious Legend model. A step up from the brand’s original hybrid, this features premium foam and two layers of springs, designed to deliver “superior stability and targeted pressure relief”. With this offer, the price of a queen drops to $2,099 (originally $2,599). This mattress has some eco-friendly credentials too: recycled steel for the springs, and a cover made from polyester woven from old water bottles.View Deal
Helix Midnight Luxe Mattress: was $1,373.80 now from $1,099 at Helix
20% off + 2 free pillows – This luxuriously thick medium-firm hybrid features zoned lumbar support for targeted support, and a premium quilted pillow top. You can choose between a breathable Tencel cover or pay a bit more for the ‘GlacioTex Cooling Cover’ which is engineered to pull heat away from your body. This Labor Day mattress sale takes 20% off, getting you a queen size for $1,899 with two pillows included.View Deal
The Big Fig Mattress: was $1399 now from $999 with code LABORDAY at Big Fig
Save $400 – Big Fig’s medium-firm cooling hybrid mattress is specifically designed for heavier bodies: the more pressure you put on it, the more the high-density foam and flexible wrapped coils react to support you. There’s $400 off the Big Fig mattress in its Labor Day sale, with a queen costing $1,399. This one comes with a 120-night trial, so you can check whether it’s right, plus a generous 20-year warranty as well.View Deal
Amerisleep AS3 Hybrid Mattress: was $1,699 now from $1,249 at Amerisleep
Save $450 – All Amerisleep mattresses qualify for this $450 discount thanks to coupon code AS450 (which is automatically applied at checkout). That includes the brand’s best-selling model, the AS3, which is now $1,499 in queen (was $1,949). The AS3 is a medium hybrid mattress that offers impressive pressure relief for side sleepers; you can see in our Amerisleep AS3 Hybrid mattress review why we rate it so highly.View Deal
Casper Wave Hybrid Mattress: was $2,395 now from $1,916 at Casper
Save 20% – Casper’s most advanced non-cooling mattress has 20% off in the Labor Day sales. A queen size Wave Hybrid is marked down to $2,316 (from $2,895), which is a great price for a high-end hybrid with zoned support. Although it’s not a Snow mattress it still has some decent cooling features; bear in mind though that there’s a small chance of a bigger discount on Labor Day itself.View Deal
Zoma Mattress: from $749 $599 at Zoma
Save up to $150 – The Zoma Mattress is a good option for active people. It’s designed to help you recover faster from training, with a ventilated cover fabric to keep you cool at night, and breathable gel memory foam to relieve painful pressure points. This deal slashes the price of a queen size from $949 to $799 – that’s $150 off. You don’t get the free bedding bundle included last year, though.View Deal
Labor Day mattress sales: Cooling mattresses
Casper Wave Hybrid Snow: was $2,895 now from $2,316 at Casper
20% off – Casper’s yet to launch an official Labor Day sale but right now there’s up to 20% off its mattress range. So if a premium cooling mattress takes your fancy, now’s the time to buy the high-end Wave Hybrid Snow. It features HeatDelete bands, cooling gel and a QuickCool cover to keep temperatures down. This advanced hybrid is now available for $2,716 in a queen size, reduced from $3,395. We saw an increased 25% discount on the 4th of July, so it could be worth holding out until Labor Day itself for the chance of a better bargain.View Deal
GhostBed Luxe Mattress: was $2,595 now from $1,298 + free pillows at GhostBed
Half price, free pillows – Side sleepers with a tendency to get hot at night would do well to check out the GhostBed Luxe. It’s a 13-inch all-foam mattress with seven layers bringing the cooling and comfort, and while we think it’s just a bit too plush for heavier sleepers as well as back and stomach sleepers, others will appreciate its cloud-like feel. There’s 50% off in the GhostBed Labor Day sale, and a queen is reduced to $1,598 with two free pillows worth $219 included; it’s the standard GhostBed discount but still a good price.View Deal
Nectar Premier Copper Mattress: was $1,499 now from $999 at Nectar
Save 33% – The original Nectar mattress does an admirable job of regulating temperature, but the Premier Copper is your best bet if you’re a hot sleeper who likes the cushioning hug of memory foam. A copper-woven cover plus phase-change-infused cooling foam will leave you comfortably cool and well-supported. Bring home a queen on sale for $1,299 (MSRP $1,949). A lifetime warranty applies, and you’ll have a full year to test it out at home.View Deal
Tempur-Pedic ProBreeze mattress: was $4,099 now from $3,599 + free accessories at Tempur-Pedic
$500 off – Tempur-Pedic makes some of the best all-foam mattresses you can get, but they’re expensive and, unlike with most brands, they’re not always reduced in price. So $500 off its cooling Tempur-Breeze range is a welcome deal; it means that you can get ProBreeze, which promises to keep things 5° cooler at night, for $4,099 in a queen size.View Deal
Labor Day mattress sales: Organic mattresses
Awara Natural Hybrid Mattress: was $1,099 now from $699 at Awara
Save $400 – The Awara Luxury Hybrid is among the least expensive organic mattresses you can get. It has a firmer feel than you may expect, and is well-suited to back and stomach sleepers, as well as to couples and those seeking enhanced back support. You’ll have a year to trial it at home, and it comes with a forever warranty. In the Awara Labor Day sale, a queen size is reduced to $999 (was $1,399).View Deal
Nolah Natural 11 Mattress: was $1,499 now from $999 at Nolah Sleep
There are are excellent savings to be had on Nolah’s only organic mattress for Labor Day. It’s offering a range of discounts up to $1,200 across its range, and where the Nolah Natural 11″ is concerned, that means up to $800 off. A queen size has $700 off, which means it’s yours for $1,399 right now; that’s $70 less than it was on sale for on the 4th of July. The Natural 11″ features pressure-relieving Talalay latex, plus organic cotton and GOTS certified wool to help you sleep cooler at night, too.View Deal
Saatva Zenhaven Latex mattress: was $1,895 now from $1,595 at Saatva
Up to $400 off – The Zenhaven is Saatva’s double-sided latex mattress, using hypoallergenic and sustainably sourced luxury latex to deliver enhanced lower back support and pressure relief, alongside a layer of organic, chemical-free wool and an organic cotton cover. The clever design can be flipped to achieve two different firmness levels: one side is a luxury plush firmness, and the other is gentle firm. There’s between $300 and $400 off for Labor Day, and a queen size is $2,945, with a $350 discount.View Deal
Avocado Latex Mattress: was $2,399 now from $1,679 at Avocado
For a great price on a latex mattress, head to Avocado where’s running a clearance sale on with 30% off the usual price, making it it a whole lot more affordable, at least while stocks last. This hand-crafted organic mattress is great for comfort and motion isolation, with just the right amount of bounce. It’s on sale in a queen size for $2,099, reduced from $2,999; that’s well worth grabbing before it sells out.View Deal
Amerisleep Organica: was $1,499 now from $1,049 at Amerisleep
$450 off – There’s $450 off all mattresses in the Amerisleep Labor Day sale, bringing the the price of this all-natural latex mattress in a queen size down to $1,299 (was $1,749). It’s not the cheapest organic mattress around, but it’s stacked with certified natural and organic materials for non-toxic, healthy sleep. It comes with a 20-year warranty and you’ll have 100 nights to trial it.View Deal
Labor Day mattress sales: mattress toppers
Puffy Deluxe Mattress Topper: was $179 now from $152 at Puffy
Puffy’s 2.5-inch customizable memory foam topper is available in two firmness ratings, and has recently taken the top spot in our guide to the best mattress toppers. Hypoallergenic, coming with a lifetime warranty and crafted with a non-slip backing, this topper will stay in place no matter how much you twist and turn. The MSRP for a Queen is $229, but there’s 15% off in Puffy’s sale, reducing the price to $195.View Deal
Tempur-Adapt Topper: was $319 now from $255.20 at Tempur-Pedic
20% off plus free gifts – The Tempur-Adapt is one of the best mattress toppers you can get, but it’s definitely a premium option. This topper features three inches of Tempur material, giving any bed an extra degree of pressure relief and comfort, and in Tempur-Pedic’s sale there’s 20% off with a Cloud pillow and sleep mask worth $118 thrown in. A queen size will cost you $335.20; however if you don’t need a pillow you can instead save 40% with the TOPPERS40 code, bringing the price down to $251.40; still not exactly cheap, but it’s a lot less than buying a whole new mattress.View Deal
Avocado Organic Latex Mattress Topper: was $549 now from $494.10 at Avocado
Save 10% – If you’re looking for an eco-friendly topper they don’t come much better than this. Avocado’s premium topper is made with certified-organic materials, including latex, wool and cotton, and comes with two sleep feels: plush or firm. There’s 10% off when you use Avocado’s LABORDAY code, which will get you a queen size topper for $584.10, reduced from $649.View Deal
Labor Day mattress sales 2023: FAQs
When do Labor Day mattress sales 2023 start?
Labor Day 2023 falls on 4 September, but we usually see promotions kicking off up to three weeks ahead of the holiday itself. These were typically marketed as early Labor Day mattress sale offers or pre-Labor Day mattress sales, but you’ll find that in the vast majority of cases, the exact same discounts ran through to Labor Day itself. In a handful of cases, a manufacturer or brand dropped a higher discount on Labor Day itself, but this is more typical of a flash sale that we normally see just before the best Black Friday mattress deals arrive in late November.
Is Labor Day a good time to buy a mattress?
Major holidays are typically a very good time to buy a mattress, and Labor Day is no exception. It’s one of the last big shopping events to occur before Black Friday and is known for featuring steep markdowns and generous freebie offers. It’s not uncommon to find some of the best deals of the year during Labor Day mattress sales.
However, keep in mind that we are in the middle of a cost of living crisis this year and inflation is affecting the mattress world just as badly as it is other sectors, so while there will be deals and discounts, the actual price of mattresses has in many cases risen over the summer.
We’ll be focusing on the best mattress sale offers here, and will explain how they compare to the deals and prices we see most months from these brands.
(Image credit: Getty)
Labor Day mattress sales: Price history
In last year’s Labor Day mattress sales, there were hundreds of deals to choose between, with big offers from popular sleep brands including Nectar, Purple and Tempur-Pedic competing with discounts from heavyweight retailers including Mattress Firm, Macy’s and Bed, Bath and Beyond. We searched through them all, and rounded up the very best Labor Day mattress sales to help you bag the biggest bargain.
The best Labor Day mattress sale came from Nectar. With $200 off every Nectar mattress – plus $499-worth of free gifts added to your order (luxury pillows, a mattress protector and sheet set) it was a tough offer to beat, dropping the price of a queen size from $999 to $799. As all Nectar mattresses come with a year’s risk-free trial and forever warranty, no other Labor Day mattress deal came close to this for value for money.
If you had a little more to spend, or preferred an innerspring mattress, we also recommended buying the luxury hybrid Saatva Classic in the Labor Day mattress sales. Saatva offered between $200 and $500 off off when you spent over $1,000, however we had an exclusive discount that knocked $375 off, which brought the price of a queen size down to $1,395. As we explain in our Saatva Classic mattress review, that hybrid is exceptional value for a handcrafted luxury bed anyway – especially with a discount.
In short, there were plenty of Labor Day mattress deals to browse, whether you were looking for the cushioning support of memory foam, the bounce of springs, a cooling hybrid option, or an ultra-durable and sustainable choice like organic latex.
5 tips for buying a mattress in the Labor Day sales
Buying a mattress online is probably easier than you think, if you’ve never done it before – and it’s likely cheaper too. Increased competition online has led to lower prices for consumers. Plus, many brands have been able to save money by choosing not to have physical stores and have instead invested in better quality materials, so you often get more for your cash when you buy online too.
To help you find exactly the right mattress, all the top brands now offer long, risk-free sleep trials so you can test them properly (and safely) by sleeping on them in your own home.
(Image credit: Cocoon by Sealy)
Most of them come with free deliveries and returns, too – all of which makes buying online an easier, quicker and more reliable way of ending up with the right mattress than spending five minutes testing one in a showroom.
Here are five things to look for when buying a mattress online:
1. Choose a mattress with at least a 60-night trial
The only way to know whether a mattress is right is to sleep on it. That’s why most top brands now offer a risk-free trial, and promise to collect the mattress and give you a full refund if you don’t like it (as long as it isn’t damaged).
We’ve made sure all the mattresses in our Memorial Day mattress sale round-up come with at least a 60-night trial – the majority come with 100 nights, and some, such as Nectar, give you an entire year to decide whether you like it.
2. Check for free returns
As part of the risk-free trial, most brands offer a full refund and free returns if you decide the mattress isn’t right for you. However, some do charge a fee for collection, around $75, so check the policy first.
3. Read third-party T&Cs
We usually recommend buying your mattress directly from the manufacturer so that you can make the most of generous sleep trial and warranties. You’re more likely to get a better deal from the manufacturer too, with competitive discounts and free gifts often added to your order.
However, sometimes a third-party retailer can run a deal that makes it slightly cheaper than buying through the manufacturer. If you’re looking for the cheapest price possible, this can be a good way to get it – however bear in mind that you may not receive the same trial or warranty benefits if you buy from a retailer such as Amazon, so always read the T&Cs carefully first.
4. Ensure it’s the right size with the elbow test
Do the elbow test to work out what size mattress you need. Lie back with your hands behind your head. If you share a bed, your elbows should be able to extend without touching your side of the bed or your partner’s elbow; if you don’t share a bed, your elbows should be able to extend without touch either side of the bed.
5. Try a new mattress for three weeks
It can take up to 21 days for your body to adjust to a new mattress. So even if it isn’t comfortable initially and you wake up with aches and pains, stick with it – particularly if your body is used to sleeping on a much older mattress. If after three weeks you still don’t like it, then you know it’s because it isn’t right, rather than because your body still hasn’t readjusted from sleeping on a less supportive or different mattress.
