Memory Foam Mattresses: The Complete Guide
Everything you need to know — how it works, who it's for, and how to pick the right one
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. That means less strain at the hips, shoulders, and lower back — particularly beneficial for side sleepers.1
0 Harmful Chemicals
Not all foam is created equal. 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 made with CertiPUR-US certified foam, so you know exactly what you’re sleeping on.2
20–30° Cooler Sleep
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. Lull’s foam is built to this standard.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.
1 Sleep Research Society, Pressure Distribution Studies, 2019
2 CertiPUR-US® Program Standard, csp.certipur.us
3 Foam industry thermal testing, Sleep Products Safety Council, 2022
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 →
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 $38/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 $61/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 memory foam last?
High-quality memory foam mattresses like Lull’s typically last 10–12 years with normal use. Memory foam holds its shape longer than innerspring because there are no coils to degrade. Lull backs this with a lifetime warranty. A waterproof mattress protector extends this further — see our Waterproof Mattress Protector guide.
Does memory foam sleep hot?
Modern memory foam runs much cooler than older-generation foam. Lull uses open-cell construction with a gel-infused top layer to draw heat away from your body. Most sleepers find it comfortable year-round. If you run extremely hot, the Luxe Hybrid adds coil airflow on top of foam comfort.
Is memory foam good for back pain?
Yes. Memory foam is consistently recommended for back pain because it contours to the spine’s natural curve, distributes body weight evenly, and eliminates pressure points that cause overnight muscle tension. Research from the Journal of Chiropractic Medicine found medium-firm memory foam reduced lower back pain in 57% of participants.
How long does memory foam take to expand?
Most memory foam mattresses reach full expansion within 4–8 hours of unboxing. Lull recommends allowing 24 hours before sleeping on it for full off-gassing and expansion, though most sleepers find it comfortable right away.
Can I use a memory foam mattress on any base?
Memory foam works on most solid surfaces: platform beds, slatted frames (slats ≤3 inches apart), adjustable bases, or the floor. It does not require a box spring. Lull’s mattresses are compatible with all standard frames and Lull’s own foundation.
What’s the difference between memory foam and hybrid?
Memory foam mattresses use only foam layers — better for pressure relief and motion isolation. Hybrid mattresses add a coil support layer — better for breathability, edge support, and a bouncier feel. Lull offers both: the Original series (pure foam) and the Luxe series (hybrid).
What Our Sleepers Say
4.6 out of 5 · 40,000+ verified reviews
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