Endorphins

The word people reach for when they want to explain why being hit can feel good. Endorphins are real. The confident chemical story built on top of them is mostly folklore, and I would rather give you the honest version.

Consenting adults only. Everything on this page is about adults over 18 who have freely agreed to it.

Written from first-hand experience or extensive research by the editor.

What it means

Endorphins are chemicals the body makes itself which act on the same receptors as opiates. They are released under pain and sustained physical stress, and they are the standard textbook explanation for why an injured person can walk a mile before noticing, and for the pleasant fog after hard exercise.

In this world, the word gets used as shorthand for the whole afterglow: the warmth, the floating, the raised pain tolerance halfway through a session, the strange contentment on the drive home. People say endorphins the way they say hormones, as a way of saying something chemical is happening and I am not making it up.

Something chemical is happening. Whether it is specifically endorphins is another question, and the popular account is a good deal more confident than the evidence.

What has actually been measured

Sagarin and colleagues took hormone samples from people before, during and after real BDSM scenes at events rather than in a laboratory, and found significant cortisol changes in receiving partners, and increases in reported closeness for couples whose scenes went well. Cortisol is a stress hormone, not an endorphin.

Ambler and colleagues, in 2017, found reduced performance on a task measuring executive function in bottoms, consistent with the transient hypofrontality seen in other intense physical states. That is a finding about the brain being partly offline, which is closer to what people actually describe than any account involving a chemical rush.

Both studies are small, self-selected and preliminary, and the 2017 one says so itself. That is still more evidence than most claims in this area can manage.

In practice

The practical value of the endorphin idea is that it predicts two things reliably, and those two things are worth acting on.

First, pain tolerance rises during a session. Strokes that were unmanageable in the first five minutes become absorbable by the twentieth. That is why warming up works, and it is also why a top who calibrates by how much she is taking at minute thirty will get it wrong. See warming up.

Second, whatever goes up comes down. The afterglow is followed for a lot of people by a dip a day or two later, which is drop. Whether or not the chemistry works the way the folk account says, planning for the comedown is sensible.

The usual mistake

Using endorphins as a reason to push further. If someone says she can take more because the endorphins have kicked in, what she is reporting is reduced feedback, not increased safety. Reduced feedback is a reason to be more careful, not less.

And treating the word as an explanation for the appetite itself. It might explain what happens during, but it does not explain why somebody wanted it on Monday morning at their desk. That is a different question, taken up on why do I like pain.