So caffeine binds to adenosine receptors to block adenosine’s drowsiness effect. Melatonin binds to melatonin receptors to regulate circadian rhythms. As far as how adenosine interacts with melatonin, no idea. I’m no biochemist and what I’m about to say could be 100% incorrect, but it seems that adenosine is involved in melatonin production?
So if it’s true that adenosine leads to melatonin production, then I’m guessing that the adenosine-blocking effect of caffeine would be (partially?) negated by ingesting a melatonin supplement, especially in the massive doses that they sell.
My money is on SLEEP. [I got it backwards!! See below replies.]
You’re on the right track, but funnily enough you got it switched around!
Research shows that melatonin binding leads to downstream release of adenosine, so if caffeine is blocking its binding action sleep is not on the way!
Here’s the paper I am referencing: https://doi.org/10.1016%2Fj.neuron.2015.02.016
“We find that melatonin promotes sleep downstream of the circadian clock as it is not required to initiate or maintain circadian rhythms. Additionally, we provide evidence that melatonin may induce sleep in part by promoting adenosine signaling, thus potentially linking circadian and homeostatic control of sleep”
