Insomnia is rarely a problem of not being tired enough—it is almost always a problem of timing. Dr. Andrew Huberman, Stanford neuroscientist and host of the popular Huberman Lab podcast, explains that most sleep issues stem from a misaligned internal clock rather than some mysterious defect in your ability to rest. Your circadian rhythm is not just a vague concept; it is a biological pacemaker that dictates when you feel alert, hungry, and sleepy. When that rhythm drifts off course, your brain releases cortisol at midnight and melatonin at noon, leaving you staring at the ceiling. The good news is that by understanding a few neuroscience principles, you can reset that clock without pills or expensive gadgets.

One of the most overlooked circadian cues is body temperature. Huberman teaches that your core temperature naturally peaks in the late afternoon and begins falling as bedtime approaches. That drop is actually a trigger for sleep initiation—your brain waits for this cooling signal before releasing melatonin. If your bedroom is too warm, you essentially block that signal. The ideal range for most people is between 60 and 67 degrees Fahrenheit, but here is the counterintuitive part: taking a hot bath one to two hours before bed actually helps. The bath raises your temperature, and the subsequent rapid cooling when you step out mimics and amplifies the natural evening drop. This temperature manipulation directly affects the preoptic area of your hypothalamus, the brain region responsible for switching you from wakefulness to sleep.

Fixing insomnia without addressing morning light exposure is like trying to bail water from a boat with a hole in the hull. Huberman stresses that light in the first thirty minutes after waking is the most powerful tool for setting your circadian rhythm. When sunlight hits your eyes, it triggers a cascade that eventually determines when your pineal gland will release melatonin that night. That timing is not immediate—melatonin typically rises about fourteen to sixteen hours after morning light exposure. So if you view light at 7 a.m., your brain naturally prepares for sleep around 9 p.m. to 11 p.m. Conversely, if you sleep in until 10 a.m. on weekends, your melatonin release shifts later, making Sunday night insomnia almost inevitable. Consistency here is more important than duration.

While morning light is medicine, nighttime light is poison for the insomniac brain. Huberman identifies the window between 10 p.m. and 4 a.m. as the most disruptive period for light exposure. During these hours, even brief pulses of bright light—checking your phone for a notification, walking to the bathroom with the overhead light on—can significantly suppress melatonin and shift your clock later. The neuroscience behind this involves a specialized cell type in your retina called melanopsin cells, which are incredibly sensitive to blue wavelengths and do not adapt quickly to darkness. One minute of phone light at 2 a.m. can trick your brain into thinking it is morning. Huberman recommends red nightlights or dim amber bulbs for nighttime bathroom trips, as these wavelengths have the least impact on your circadian system.

Here is a protocol that rarely appears in typical sleep advice: try to view natural light during the late afternoon or sunset. Huberman explains that light at low solar angles—the golden hour—contains a different color spectrum that actually helps your brain calibrate the length of the day. When your eyes detect the shift toward redder wavelengths at dusk, it sends a preparatory signal to your pineal gland that darkness is approaching. This does not directly cause sleep, but it trains your circadian system to recognize the transition from day to night. Even fifteen minutes of outdoor light between 4 p.m. and 6 p.m. can improve your brain’s ability to release melatonin at the correct time. People who spend all day indoors under artificial light miss this critical cue entirely.

Many insomniacs rely on coffee to function during the day, but Huberman warns that caffeine directly interferes with the brain’s sleep-pressure system. Here is the neuroscience: throughout the day, a chemical called adenosine builds up in your brain, creating a gentle pressure to sleep. Caffeine works by blocking adenosine receptors, essentially silencing your brain’s fatigue signal. That is fine early in the day, but caffeine has a half-life of about five hours, meaning a 2 p.m. coffee still leaves significant stimulation by 10 p.m. The real problem is that chronic caffeine use can cause your brain to grow more adenosine receptors, making you even more dependent while worsening your natural sleep drive. Huberman recommends stopping caffeine by 2 p.m. at the absolute latest, and ideally before noon for severe insomnia cases.

When you cannot fall asleep despite your best efforts, Huberman offers a neuroscience-backed alternative called non-sleep deep rest, or NSDR. This practice involves lying down with your eyes closed and following a body scan or yoga nidra for ten to twenty minutes. Even without losing consciousness, NSDR has been shown to increase dopamine levels, reduce cortisol, and promote a brain state similar to early-stage sleep. More importantly for insomniacs, NSDR breaks the anxiety cycle where lying awake makes you frustrated, which raises cortisol, which makes sleep even harder. Huberman suggests using NSDR during the afternoon if you feel exhausted, or as a replacement for sleep on nights when rest simply will not come. Over time, this practice retrains your brain to associate lying still with relaxation rather than struggle, making spontaneous sleep more likely.