The Four Stages of Sleep

The Four Stages of Sleep

You’re here to get better sleep. So are we. The pursuit of better sleep is what brought us all to Proper—and we are united in this pursuit because of its importance and because of the challenges we all face. Trust us, if we found sleep simple, we’d be working on something else.

But improving your sleep begins with understanding it. So here we go today tackling sleep cycles. You’ve certainly heard of them, but what are they comprised of? What is their function? Let’s get right to it.

Stages of sleep are typically broken down into REM and Non-REM sleep. While true, this oversimplification is masking some important differences we need to know about non-REM stages. Sleep can be broken into four distinct stages: N1 (light sleep), N2 (deeper sleep), N3 (deep sleep), and N4 (REM sleep), and each stage unfolds with significance and purpose. And here at Proper, we know you can handle more than just two generalized categories, so join us on a journey through a typical night’s four stages of sleep.

As the day comes to a close, our body’s natural circadian rhythm kicks into the sleep preparation phase, bringing down our cortisol levels (the stress hormone) and kicking up our melatonin levels. Many things can mess with this transition, and much of our modern world is set up in opposition to how our bodies would like our rhythms to progress, which we will cover in another post. As we’ve wound down in bed and fallen asleep, we enter stage the first stage, which we call N1.


N1 - Light Sleep

N1 is the lightest sleep stage. It is a necessary initiation phase for our approximately 90-minute sleep cycles, and features primarily alpha and theta waves in the brain, in contrast to our brain being dominated by beta waves during wakefulness. Our muscles retain their tone. But N1’s primary function is to get us along to N2, which is a bit deeper.

Proper's ingredients that aid N1: Melatonin; GABA; Valerian Root Extract; Venetron®; Sensoril® Ashwagandha; MicroActive® Melatonin.


N2 - Deeper Sleep

N2 is deeper sleep and is the most common stage of sleep overnight, usually about 45% of our total sleep. Our body temperature drops along with our heart rate, and our baseline brain waves synchronize to between 4 and 8 waves per second. This stage introduces a phenomenon called sleep spindles, which are brief powerful bursts of coordinated neuron firing at 12-15hz frequency. Sleep spindles are thought to be an important component of long-term memory consolidation. K-Complexes also show up in this sleep stage, which are long delta waves that last about one second and are believed to be important in maintaining sleep itself and memory formation. If all goes well, we pass from N2 to N3 after about 25 minutes.

Proper's ingredients that aid N2: Venetron®; Sensoril® Ashwagandha; MicroActive® Melatonin.


N3 - Deep Sleep

N3 is the deepest non-REM sleep, and is critical to our physical and brain health, but is also one of the hardest stages to get for many people and becomes harder as we age. This is slow wave (Delta wave) sleep, and if you’ve ever been awoken during this stage, you know that it may take a few moments to re-orient yourself. This is the stage where our bodies and brains are in full-on repair mode—our brains are being washed by our cerebrospinal fluid during this stage, helping to clear out plaques and detritus. Getting sufficient N3 thus may be important in avoiding neurodegenerative disorders like Alzheimer’s disease. In fact, a hallmark symptom of Alzheimer’s is a decrease in time spent in N3, potentially creating a feedback loop of accumulating plaques and poor sleep. Adding to its importance is N3 is also when our immune cells recover, and our body improves our insulin sensitivity.

On a given night, N3 is more common in our earlier sleep cycles, as later sleep cycles replace N3 with the REM stage, so it is important that not only do we eventually sleep well, but that we sleep well and deeply at the beginning of our night to get this time in deep sleep and our bodies and brains can repair and restore themselves.

Proper’s ingredients that impact N3: Venetron® (shown to increase delta waves and non-REM sleep time); Sensoril® Ashwagandha; MicroActive® Melatonin.


REM (Rapid Eye Movement)

REM sleep is commonly understood as the sleep cycle during which we dream. During REM Sleep, our brains are active—so much so that sleep technicians can’t just monitor brain electrical activity during sleep studies to know if someone is in REM because it is almost indistinguishable from being awake. REM sleep is critical for emotional processing, which is perhaps what is happening while we dream. Notably, our bodies entirely lose muscle tone during REM, meaning if you picked someone up who was in REM, their limbs would flop towards the ground. This may be to protect us from taking physical action while in our dream state, which would of course be quite dangerous.

Proper’s ingredients that impact REM: Sensoril® Ashwagandha; MicroActive® Melatonin.


Our bodies developed these sleep stages over millions of years because they are important. It is highly costly to not be searching for food or a mate for 8 hours out of every day. We sleep because it is critical to our physical health, our brain health, and our mental health.

We at Proper are doing what we can to make getting a complete and restful night’s sleep as easy as possible, without forming dependency, risking long-term brain health, or feeling groggy in the morning. Our formulations are backed by science and built with this pursuit in mind. Here’s to getting a great night’s sleep.


MicroActive® Melatonin is a registered trademark of BioActives, LLC.
Sensoril® is a registered trademark of Natreon, Inc.
Venetron® is a registered trademark of Tokiwa Phytochemical Co. Ltd.