What Happens if You Sleep on a Memory Foam Mattress Before 24 hours

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Written by: Alex Savy
Read 8 minLast updated on February 22, 2023

So you just purchased a new bed. A hearty congratulations to you!

Now you're home, it's nighttime, and you're staring at your bed wondering if it's okay to disregard the company's instructions and sleep on a memory foam mattress before 24 hours. 

Would sleeping on it before time damage it? Is there any inherent threat to your health if you choose to lie on your bed, say, only 12 hours after purchase? Should you or should you not? 

Before you dive onto your bed, let's dive into this article first. Here, you'll find out valuable answers about sleeping on a newly purchased mattress.

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Right or Wrong: Lying on a New Mattress

So here comes the question you've been waiting for:  

Can you sleep on a memory foam mattress before 24 hours

Yes, you can! 

Laying on a new mattress

Laying on your bed before it fully spreads won't do any damage to it. 

Psst! Here's a secret:

You won't be the first to do it, nor will you be last. 

So if there's no harm in using a bed that's yet to expand, why in the world did the cheeky salesman tell you not to lay on it before time. 


Every manufacturer knows their product. And they always want customers to have the best experience.

The best way manufacturers can guarantee customer comfort is to give out instructions to only use products in certain optimum conditions. 

That is, you can spread across your new bed, but you might not feel comfortable sleeping on it. 

Another reason bed manufacturing companies dissuade customers from using a bed before it's due is to prevent potential health issues that may result from harmful chemical release from the bed. (1)

Alternatively, you could opt for other mattresses without memory foam if you feel uncomfortable about off-gassing.

How to Know a  Fully Inflated Mattress 

If you're a patient fellow and can find other sleeping alternatives pending your bed's full expansion, here's the tell-tale sign to know when your fresh-out-of-the-box mattress is ready for use

The bed will fully stretch out with all its corners solid and defined. 

It's imperative to note that the best mattresses will reach 90 percent enlargement within 12 hours, but only after 24 hours will the beds’ edges fill out and take shape.

Factors Determining a Mattress's Expansion

Factors Determining a Mattress's Expansion

A mattress's expansion pace depends on three factors: 

  • Thickness

The thickness of memory foam is proportional to the length of time it takes for expansion. That is, the thicker a mattress, the lengthier the time for enlargement. 

  • Density

In terms of density, beds come in three versions, Low, Medium, and High. A high-density mattress will take longer to spread out than a lighter version and vice versa. 

Are you confused as to which to choose? Check out some of the best memory foam mattresses, according to Reddit

  • Temperature

Memory foams possess specific elastic properties that are susceptible to heat effects. Moderate heat levels make the bed's flexible components stretch faster, thus guaranteeing a softer, plusher, marshmallow-like mattress.

How to Quicken Mattress Inflation

You can shorten the duration it'll take for a bed to fully expand by doing the following.

  • Lie on it

The fastest way to get a mattress to spread out is to lie on it. 

Quite an irony, isn't it? 

But it's the truth. 

Lying on a newly unboxed bed helps to stretch the foam's material faster.

Since the foam has undergone compression before getting into a box, the best thing to quicken up the expansion rate is to 'distort' the compressed particles by lying on the mattress. 

Quote Box 

You could further speed up the mattress inflation process by giving your bed a foot massage to free up those tightly packed molecules. Endeavor to do so with clean feet to avoid staining your new bed.

  • Warm-up Your Room

A warm room does to a bed what an oven does to a cake: it makes it rise and spread faster.

Now you don't need to apply oven-level hotness to your bed. Instead, you only need to make the room warm enough so the viscoelastic materials can gain more fluidity. 

You can turn on the heater to achieve this, or you could simply roll on the bed so your body heat and friction can apply the needed warmth.

When a Mattress Fails to Expand

Using a memory foam before it fully spreads doesn't stop its inflation. Typically, most beds require one full day to inflate completely. However, if the memory foam is not expanding, it's advisable to observe for another day before returning it or seeking a refund.  In fact, closely observing a mattress could be the deciding factor that saves you from  catastrophic lung failure as some mattresses that release harmful fibreglass may remain undetected in most homes until a major life-threatening occurrence.(2) Should a mattress fail to expand after 48 hours, it's mostly a fault from the manufacturer's end. 

Also: check here for memory foams without fiberglass


How Long for Memory Foam Mattress to Expand?

Typically, one full day is the ideal expansion time for a mattress, but some products may require an additional 24 hours for complete inflation.

Can I Sleep on my Memory Foam Mattress Right Away?

You shouldn't sleep on a memory foam mattress right after unboxing it because it gives off some chemicals.

Do You Have to Wait 48 Hours for Memory Foam to Inflate?

No, you don't necessarily have to wait 48 hours for the memory foam to inflate. You can start using your bed 4 hours after unboxing.


It’s okay to sleep on a memory foam mattress before 24 hours. However, you might not experience true comfort from a bed that's yet to expand fully. 

Have you ever slept on a mattress before it fully inflated? On a scale of 1 to 10, rate the quality of your sleep in the comment section.


  1. The United States Environmental Protection Agency, Volatile Organic Compounds' Impact on Indoor Air Quality. Retrieved from
  2. Az Family: Family forced to leave home over fiberglass mattress cover (2017). Retrieved from

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