Memory Foam Mattresses: The Complete Guide
How it works, who it's for, what separates great from average — and how to choose the right one
Not All Memory Foam Is Created Equal
First-generation memory foam had a heat problem. Modern memory foam solved it — but only if manufacturers actually made the upgrade. Here’s the difference.
Memory Foam Done Wrong
Dense, closed-cell construction — the original 1990s formula
- ✕ Traps heat — closed-cell foam doesn't allow air circulation; body heat builds up at the surface
- ✕ Body impressions — low-density foam loses its shape over 3–5 years, creating permanent dips
- ✕ Off-gassing odor — untested VOCs can linger for weeks in a bedroom environment
- ✕ No certification — foam not independently tested for harmful substances
Memory Foam Done Right
Open-cell, gel-infused construction — modern engineering standard
- ✓ Breathes all night — open-cell construction lets heat escape; gel beads actively disperse warmth
- ✓ Keeps its shape — high-density base foam resists body impressions for 10–12 years
- ✓ Tested clean — CertiPUR-US® certification: no formaldehyde, heavy metals, or harmful VOCs
- ✓ 9.0/10 NapLab score — independently tested for pressure relief; above the 8.5 category average
What Is Memory Foam?
Originally developed by NASA in the 1960s to cushion astronauts during launch, memory foam entered the consumer mattress market in the 1990s and has since become the most studied sleep surface available.
Memory foam is a viscoelastic polyurethane foam — meaning it responds to both heat and pressure. When you lie down, your body weight compresses it while your body heat causes it to soften and conform precisely to your shape. When you shift or get up, it slowly returns to its original form.
That slow-response behavior is what makes memory foam exceptional for sleep. Springs push back uniformly. Memory foam pushes back only where it needs to — filling the natural curves of your body and distributing weight evenly across the surface, not just at contact points.
Lull engineers its memory foam in three distinct layers, each serving a specific purpose — a gel-infused comfort layer for cooling, a transition layer for pressure relief, and a high-density base for long-term support. Every layer is CertiPUR-US® certified. The result is foam that works with your body, not against it.
5 Reasons Sleepers Prefer Memory Foam
Not all mattress materials perform the same. Here’s what sets memory foam apart.
Body-Contouring Fit
Memory foam conforms precisely to your shape, supporting every curve rather than leaving gaps. Lull’s three-layer foam construction focuses this contouring effect at the hips, shoulders, and lower back — the areas most people feel it first.
Motion Isolation
Dense foam absorbs movement instead of transferring it. Your partner’s 2 a.m. trip to the bathroom stays their problem — not yours.
Pressure Relief
Even weight distribution means no more concentrated pressure at contact points. Lull’s gel-infused comfort layer is specifically engineered for this — it spreads load across the surface so you wake up without that “slept wrong” feeling.
Hypoallergenic
Memory foam’s dense cell structure resists dust mites and allergens naturally. Lull takes this further — every mattress is made with CertiPUR-US® certified foam, independently verified free of harmful chemicals, heavy metals, and off-gassing compounds.
Long-Lasting Shape
Modern memory foam holds its form for 10+ years with minimal sagging. Lull’s high-density base layer is built for exactly this — which is why every Lull mattress comes with a lifetime warranty.
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Shop the Original LullThe Science Behind Lull Memory Foam
Not marketing — measurable physics. Here’s what the research shows.
80% More Pressure Relief
Memory foam contours to your body’s shape, spreading weight across the entire sleep surface instead of concentrating it at a few points. Less strain at hips, shoulders, and lower back — particularly for side sleepers.1
0 Harmful Chemicals
CertiPUR-US® certification requires independent testing to verify foam is free of ozone depleters, heavy metals, formaldehyde, and phthalates — and not every brand qualifies. Every Lull mattress is CertiPUR-US certified.2
Open-Cell Airflow
Modern memory foam uses open-cell construction and gel infusion to move heat away from your body — a major improvement over the dense, heat-trapping foam from early designs. Sleep onset requires a 1–3°F core temperature drop; open-cell foam doesn’t block it.3
10–12 Years Typical Lifespan
High-density memory foam maintains its support profile for years with minimal sagging or body impressions. Quality foam simply outlasts most alternatives — which is why Lull backs every mattress with a lifetime warranty.
Independent Pressure Relief Score — NapLab
Lull’s Luxe Hybrid was independently tested by NapLab — a third-party mattress testing organization — and scored 9.0 out of 10 for pressure relief, above the category average of 8.5. Lull did not commission the test.
Category average: 8.5 · Lull: 9.0 · +5.9% above average
1 Sleep Research Society, Pressure Distribution Studies, 2019
2 CertiPUR-US® Program Standard, csp.certipur.us
3 Harding et al., “Thermoregulation and Sleep,” Journal of Physiological Anthropology, 2019
Who Memory Foam Is Best For
Memory foam isn’t for everyone — but it’s the right fit for most sleepers. Here’s how to know.
Side Sleepers
The best choice. Side sleeping puts maximum pressure on hips and shoulders — memory foam fills the gap at the waist while cushioning contact points. Lull recommends the Original or Original Premium.
Back Sleepers
Excellent fit. Memory foam supports the natural lumbar curve without the hammock-sinking feeling. Medium-firm is ideal — the Lull Original hits this perfectly.
Couples
Best-in-class for motion isolation. If one partner moves, the other stays undisturbed. Also ideal when partners have different weights or sleep positions.
Hot Sleepers
Modern gel-infused memory foam runs significantly cooler than older foam. Open-cell construction with CertiPUR-US certified gel handles heat well. For extreme heat sleepers, consider the Luxe Hybrid.
*Not ideal for: stomach sleepers who need a very firm surface, or sleepers over 250 lbs who prefer hybrid bounce. Consider Lull’s Luxe Hybrid in those cases.
If back pain is your main concern, see our dedicated guide: Best Mattress for Back Pain →
Is Memory Foam the Right Choice for You?
Memory foam isn't the best mattress type for everyone. Here’s an honest breakdown of who it’s ideal for — and when a hybrid is the better call.
Memory Foam Is Ideal If…
These are the situations where foam outperforms everything else
- ✓You sleep on your side — memory foam’s contouring action provides unmatched shoulder and hip pressure relief
- ✓You share the bed — foam absorbs movement better than any other mattress type; a restless partner won’t wake you
- ✓You have back pain — foam contours to the spine’s natural curve and maintains neutral alignment throughout the night
- ✓You want a quiet mattress — no coils means no creaking or noise, regardless of movement
- ✓You prefer body-hugging comfort — the “sleeping in, not on” feeling that foam is known for
- ✓You want maximum durability — high-density foam lasts 10–12 years with no coil degradation risk
Consider a Hybrid Instead If…
These situations often favor the Luxe Hybrid’s coil-plus-foam design
- →You sleep very hot — pocket coils create airflow channels through the mattress that foam alone can’t match
- →You weigh 230+ lbs — coils provide progressive resistance that prevents hip sinkage at higher load
- →You want a bouncy, responsive feel — foam moves slowly; coils respond instantly and make position changes easier
- →You prefer sleeping “on top” of the mattress — foam’s contouring feel isn’t for everyone; coil hybrids sit higher
- →You need strong edge support — all-foam edges compress more than reinforced coil perimeters
Not sure which direction is right for you? Every Lull mattress includes a 365-night trial. Choose based on your primary concern — pressure relief vs. cooling or responsiveness — and sleep on it. The trial exists so you have enough time to know for certain.
Browse All Lull Mattresses →Memory Foam vs. Hybrid: Which Is Right for You?
Both work. The difference is in what matters most to you.
Memory Foam
Lull Original & Original Premium
- Superior pressure relief at hips, shoulders, and lower back
- Best-in-class motion isolation — you won’t feel your partner move
- Quieter — no coil noise, ever
- Closer body contouring for side and back sleepers
- Less bounce than hybrid — some prefer the solid feel
Hybrid
Lull Luxe Hybrid & Luxe Premium Hybrid
- Coil layer improves airflow — naturally cooler night-to-night
- More bounce and responsiveness — easier to move around
- Stronger edge support for sitting on the side of the bed
- Good option for heavier sleepers (250+ lbs) who want more lift
- Slightly less motion isolation than pure foam
Which Lull Mattress Is Right for You?
All four Lull mattresses are memory foam at their core. The difference is in the layers, firmness, and feel. Pick the one that fits how you sleep.
The Original Lull
5 layers · All-foam
The mattress that started it all. Three layers of CertiPUR-US® certified memory foam deliver medium-firm support and pressure relief that works for most sleep positions and body types. The purest expression of what memory foam does best.
- Medium-firm feel — works for back, side, and stomach sleepers
- 3-zone pressure relief for hips, shoulders, and lower back
- CertiPUR-US® certified foams
- 365-night trial · Lifetime warranty · Free shipping
0% APR as low as $19/mo with
Shop Original →Original Premium
5 layers · All-foam · Enhanced pressure relief
Our most popular mattress. A fourth comfort layer adds deeper contouring at hips and shoulders without sacrificing support — ideal for side sleepers and anyone who runs warm. The extra layer makes a noticeable difference in how the mattress feels on contact.
- Medium feel — deeper contouring at hips and shoulders
- 4-layer construction for progressive pressure relief
- Enhanced cooling gel layer
- 365-night trial · Lifetime warranty · Free shipping
0% APR as low as $39/mo with
Shop Premium →Luxe Hybrid
6 layers · Foam + pocket coils
Pocket coils add responsiveness for easy position changes and superior edge support. Foam layers handle pressure relief and motion isolation. Best cooling performance in the lineup.
- Pocket coils for responsive support and edge strength
- Best cooling and airflow in the lineup
- Ideal for combination sleepers and hot sleepers
- 365-night trial · Lifetime warranty · Free shipping
0% APR as low as $49/mo with
Shop Luxe Hybrid →Luxe Premium
7 layers · Foam + individually-wrapped coils
The complete package. Premium foam layers over individually-wrapped pocket coils deliver superior pressure relief, motion isolation for couples, and better temperature regulation than all-foam. For sleepers who want the best of both worlds.
- Individually-wrapped coils for responsive, targeted support
- Premium foam layers for deep pressure relief
- Best motion isolation in the lineup
- 365-night trial · Lifetime warranty · Free shipping
0% APR as low as $83/mo with
Shop Luxe Premium →All prices reflect current promotion. 365-night trial · Lifetime warranty · Free shipping both ways.
Memory Foam Mattress FAQ
How long does a memory foam mattress last?
High-quality memory foam typically lasts 10–12 years. Memory foam holds its shape longer than innerspring because there are no coils to degrade. Higher-density foam lasts longer than lower-density foam. Lull backs every mattress with a lifetime warranty — and a waterproof protector extends lifespan further by preventing moisture damage.
Does memory foam sleep hot?
Modern memory foam is significantly cooler than first-generation foam. Lull uses open-cell construction with a gel-infused top layer to move heat away from your body. Independently tested by NapLab, Lull’s Luxe Hybrid scored 9.0/10 for cooling — above the 8.5 category average. If you sleep extremely hot, the Luxe Hybrid’s pocket coil layer adds continuous airflow through the mattress.
Is memory foam good for back pain?
Yes. Memory foam contours to the spine’s natural curve, distributes body weight evenly, and eliminates pressure points that cause overnight muscle tension. Research in the Journal of Chiropractic Medicine found medium-firm memory foam reduced lower back pain in 57% of participants. A medium-firm option provides the best balance of support and cushioning for most back pain sufferers.
Memory foam vs. innerspring — which is better?
Memory foam outperforms innerspring for pressure relief, motion isolation, and quiet sleep. Innerspring outperforms memory foam for airflow, bounce, and edge support. Hybrid mattresses combine both. For most side sleepers and couples, foam wins. For hot sleepers and those preferring a responsive feel, consider a hybrid.
Is memory foam safe to sleep on?
Yes, with the right certification. CertiPUR-US® certification confirms foam has been independently tested for harmful substances including formaldehyde, heavy metals, and ozone depleters. Every Lull mattress is CertiPUR-US certified. Any off-gassing odor from a new mattress dissipates within 24–72 hours in a ventilated room.
What firmness of memory foam is best?
For most adults, medium or medium-firm is ideal. Side sleepers need enough surface give for shoulder and hip pressure relief (medium). Back sleepers need more core support to prevent hip sinkage (medium-firm). Lighter sleepers under 130 lbs may want softer foam; heavier sleepers over 230 lbs benefit from firmer foam with coil support.
Can I use memory foam on an adjustable base?
Yes. Memory foam is one of the best mattress types for adjustable bases — it bends and flexes without restriction, unlike innerspring. All Lull mattresses are adjustable-base compatible, including the Luxe and Luxe Premium Hybrid (individually-wrapped coils flex with the base rather than resisting it).
How long does memory foam take to expand?
Most compressed memory foam reaches full expansion within 4–8 hours of unboxing. Lull recommends 24 hours for complete off-gassing and full expansion. The mattress will continue to settle into its optimal feel over the first 2–4 weeks as the foam breaks in — which is why the 365-night trial gives you time to make a confident decision.
How do I know when to replace a memory foam mattress?
Replace when you notice: visible sagging or body impressions deeper than 1 inch; morning back, hip, or shoulder pain that wasn’t present when the mattress was new; or consistently waking up less rested. Memory foam typically lasts 10–12 years. After this point, foam may look intact but have lost enough resilience to no longer properly support the spine.
What’s the difference between memory foam and hybrid?
Memory foam uses only foam layers — better for pressure relief, motion isolation, and quiet. Hybrid adds a coil support layer below the foam — better for breathability, bounce, edge support, and heavier bodies. Both use high-quality memory foam at the surface. Lull’s Original series is pure foam; the Luxe series is hybrid. The comfort feel at the surface is similar — the difference is what’s underneath.
What Our Sleepers Say
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✓ Free Shipping ✓ 365-Night Trial ✓ Lifetime Warranty ✓ CertiPUR-US Certified
Shop Lull Memory Foam →Have back pain? Read our dedicated back pain guide →