You probably reach for coffee within minutes of waking up, almost on autopilot. But that early cup might be dulling its benefits and working against your energy later in the day.

For those experimenting with caffeine timing, the idea of waiting about 90 minutes before having caffeine is getting attention. And while there hasn’t been direct research on the effects of coffee timing, some studies point to the potential benefits of holding that first coffee until later.

Read more: Ultrahuman Caffeine Window PowerPlug explained

Highlights

  • Caffeine during your cortisol peak may land as jitteriness for some people.
  • Caffeine masks fatigue rather than removing it – when it wears off, the tiredness lands, often as an afternoon slump.
  • That slump drives a second cup, pushing caffeine later into the day, where it’s most likely to cost you sleep.

The morning cortisol spike

Your body is wired to wake up without caffeine. Within 30–45 minutes of rising, your brain releases a surge of cortisol – a hormone that supports alertness, metabolism, and stress response. This natural rise is known as the Cortisol Awakening Response (CAR). [1]

For some people, caffeine during this cortisol peak can backfire. Instead of boosting your energy, it stacks on top of an already-alert system, potentially increasing jitteriness, anxiety, and overstimulation. [2]

Adenosine and the afternoon crash

Caffeine doesn’t remove fatigue – it hides it. It binds to your adenosine receptors and blocks the signal, so the tiredness is still there. Then it wears off. [3]

Caffeine has a half-life of around 4–6 hours, so a large morning dose is fading by early afternoon – and everything it was masking becomes noticeable at once.

When people crash, the first thing they often do is reach for another coffee. But this afternoon hit can impact sleep later, fragmenting deep sleep and causing knock-on tiredness the next day [4], which many will, you guessed it, fix with more coffee.

The bottom line

The good news is that you don’t need to give up coffee. The evidence around delaying that first coffee isn’t well tested, but for those who may be experiencing crashes or jitters, testing a caffeine delay could be effective.

Waiting around 90 minutes lets your natural cortisol rise do its job first, so caffeine adds to an already-alert system rather than substituting for one.

Start your morning with hydration, natural light, and light movement. Then have your coffee – and notice how it feels.

References

  1. Cortisol Awakening Response – Stalder et al ., Assessment of the cortisol awakening response: Expert consensus guidelines, Psychoneuroendocrinology (2016).
  2. Caffeine and anxiety – Liu et al., Caffeine intake and anxiety: a meta-analysis (2024), PMID 38362247.
  3. Caffeine as adenosine antagonist – Ribeiro & Sebastião, Caffeine and adenosine, J Alzheimers Dis (2010), PMID 20164566.
  4. Caffeine and sleep architecture – Drake et al ., Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed, J Clin Sleep Med (2013). PMID 24235903.

THE AUTHOR

Ashima Raizada

Ashima Raizada is a fitness enthusiast and yoga therapist who helps people reverse lifestyle diseases by making simple lifestyle changes. She’s a voracious reader, a freelance writer, an avid traveller and an occasional bathroom singer.