Hi there, it's Matt here and welcome back to the podcast.

Now, there's a difficult truth for most people, which is that they have probably been taking

melatonin in entirely the wrong way and for the wrong assumed reason.

Not wrong in a disastrous sky is falling way, but wrong in a subtler sense.

You've been asking it to do a job it was never hired to perform, nor has the skill to accomplish.

Melatonin is not your brain's sleeping pill. It's your brain's clock whisperer, a nightly messenger telling your system

when night has begun far more than how intensely to sleep. In this episode, I want to tell you

the full story of that whisper, where melatonin comes from, what it can and cannot do for

insomnia, when it really shines for jet lag circadian

rhythm disorders and shift workers and what we're starting to learn about its long-term safety

including that worrying sounding but more nuanced recent social media frenzy about the risk of heart failure in long-term

melatonin users. Let's start inside your skull. Deep in the brain sits a tiny pea-size structure

called the pineal gland. For a long time, it was the anatomical equivalent of a locked room with no label.

Then researchers discovered that when darkness falls, this gland begins secreting a hormone,

melatonin, into the bloodstream. And as morning light returns, the secretion falls away again. Melatonin, in other words,

is the body's internal sunset announcement. It doesn't slam you into unconsciousness. It steps

onto the stage in the evening and says to every cell, it is biological night. Power down, begin the transition to sleep. In circadian biology,

we call melatonin a chronobiotic. That's just a fancy term for a substance that can shift the

timing of your internal body clock. If sleep is surfing, melatonin is not the wave and not the surfboard. It's the tide chart

telling you when the swell is likely to arrive. Take melatonin at the right time and you paddle

into position ahead of the wave. Take it at the wrong time and you're paddling in the wrong direction,

wondering why nothing is happening. There are really two melatonins in this story. One is endogenous.

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