The Weird Science Behind Morning Wood

cover1As far as problems go, morning wood isn’t the worst one to have.

It can be a bit annoying though, especially if you have roommates. Perhaps some of you have mastered the waistband tuck as you walk down the hallway to the bathroom to brush your teeth, antenna precisely adjusted. Or maybe you’ve found a more labor-intensive method for putting your soldier at ease.

But whatever your tactic of choice may be, have you ever wondered why you so often wake up on high alert?

Well thank god the scientific community has fully investigated the phenomenon, and I fucking love science recently published a thorough report.

Here are the warm, hard facts:


  • The proper name for morning wood is “nocturnal penile tumescence,” and they normally occur three to five times per night, unless you have erectile dysfunction (so be happy if you can’t tame yourself in the AM)
  • Believe it or not, NPT begins in utero. So like, baby boners — ew.
  • Women also have a similar body response called clitoral erections and vaginal engorgement during sleep. (In related news, this is the first time Queerty has published the term “vaginal engorgement.”)
  • NPT is associated with REM (rapid eye movement) sleep, with one school of thought saying that, “during REM sleep, noradrenergic cells (neurons that release the neurotransmitter noradrenaline [norepinephrine]) located in an area of the pons (part of the brainstem) called the locus coeruleus are switched off. It is thought that these cells are associated with the inhibitory tone of the penis; therefore, when their activity is reduced during REM sleep, testosterone-dependent excitatory tones can be expressed which result in an erection.”
  • As for why? Well some argue that it’s the body’s way of protecting your junk. Erections oxygenate the penile tissue, and in turn keep it viable and prevents erectile dysfunction.
  • Or it keeps you from wetting the bed. When the bladder becomes full it can trigger an erection to keep you from releasing. But that seems to be a less popular explanation.

So there you have it — way more than you ever needed to know about your morning wood. But rather than be annoyed next time, you can at least rest easy knowing that your body is doing what it can to keep your penis happy and healthy.

h/t I fucking love science