Caffeine is so bad for you that your body has to spread it out to every region including your brain so that you don’t die while your liver slowly detoxes it. It then blocks your adenosine receptors causing uncontrolled neuron firing in your brain. This causes an emergency mode in your body which triggers the pituitary gland to release ACTH.
ACTH tells your adrenals to pump out stress hormones by more than 200% (which is why your feel alert). This increases your heart rate and your blood pressure, restricts bloodflow to your brain, dampens digestive processes causing putrification in your gut, releases sugar into your bloodstream, disrupts the metabolism of GABA, decreases the absorption of thiamin, calcium, magnesium, potassium, iron, zinc, and some B vitamins.
Over time, this constant stress weakens your adrenals, lowering the output of DHEA leading to a state known as adrenal insufficiency. Making you tired, depressed, and weak.
Further, the stress response stimulates the survival part of your brain know as the limbic system. Which takes activity away from the higher functioning brain called the cerebrum and the prefrontal cortex which is involved in planning and abstract thinking. Overtime, this dampens your ability to delay gratification for long term goals, leading to short term pleasure seeking activities.
It’s addictive, has many side effects, fucks your stage 4 sleep, and increases your risk for many diseases. Get off of it ASAP.
Rant over.
Edit:
Some interesting articles:
https://www.youtube.com/watch?v=jqcnfYfYYdY
https://pmc.ncbi.nlm.nih.gov/articles/PMC2748160/
https://www.sciencedirect.com/science/article/abs/pii/S0195666305001133?via%3Dihub
https://pmc.ncbi.nlm.nih.gov/articles/PMC2249754/