Body stress is physical. It can come from lack of sleep, blood sugar spikes, poor nutrition, infection, inflammation, hard training, dehydration, alcohol, or too much caffeine. Mental stress, on the other hand, is psychological. It can come from pressure, fear, responsibility, conflict, uncertainty, emotional strain, or the constant feeling that your mind never fully shuts off.

In essence, your gut is an unsung chemical factory, quietly manufacturing the raw materials your brain depends on to stay balanced and resilient.

If dose is the what, timing is the when, and melatonin is exquisitely sensitive to it. Taken in the early evening, a small dose helps set your internal clock so sleepiness arrives on cue (this is the same clockwork that makes melatonin useful for jet lag). Take it at the wrong time, and you can nudge the clock the wrong way[8].

Before your immune system launches a full response, your body tries to stop invaders at the door.

Your skin is a physical wall. Your nose traps particles in mucus. Tiny hair-like structures called cilia line your airways and help move mucus, dust, and irritants up and out before they can settle deeper in the lungs.