If you consume health and neuroscience-related information from other podcasts and newsletters, you’ve probably stumbled upon the advice of delaying your caffeine intake in the morning for 90-120 minutes.

I’ve seen this advice a few times, and as a caffeine junkie (I couldn’t survive without my morning coffee!), it immediately caught my attention.

I wanted to learn what’s behind the recommendation of delaying your morning caffeine intake, so I took a deep dive into the scientific literature. I’m sharing my results with you in this newsletter edition.

What counts as caffeine consumption?

Coffee is the classic source of caffeine, but it’s also found in tea, energy drinks, Coke, and even chocolate. Caffeine is known for its stimulant effects, and it’s estimated that around 80-90% of the world’s population consumes it in some form.

The “delay your morning caffeine intake” advice

This advice has been circulating in the biohacking community for a while. The idea is to wait 90-120 minutes after waking before consuming caffeine to avoid afternoon crashes, that is, feeling tired and unable to concentrate after lunch.

The explanation behind it sounds logical:

• It revolves mainly around adenosine, a molecule that circulates in your system and makes you sleepy.

• Adenosine accumulates over the day and is cleared while you’re asleep.

• The proponents of the idea claim that some adenosine still remains in your system when you wake up, and your body gradually clears it over the first 90 minutes.

• Because caffeine doesn’t eliminate adenosine but only blocks its receptors, consuming it too early would interfere with adenosine clearance.

What’s right and what isn’t

The claim that caffeine doesn’t eliminate adenosine but only blocks its receptors is supported by scientific evidence.

But here’s the thing:

There's no convincing evidence that adenosine levels continue declining for 90 minutes after waking. Instead, adenosine levels start rising immediately when you wake up. And so, there’s also no scientific foundation for the claim that immediate caffeine intake interferes with your body’s natural adenosine clearance response in the morning.

Another aspect often mentioned in the context of this advice is that early caffeine intake interferes with your natural cortisol awakening response, a steep rise in your cortisol levels during the first 30-45 minutes after waking. The idea is that caffeine intake during that window could spike your cortisol to unhealthy levels.

While it’s correct that caffeine increases cortisol levels, this effect is blunted or even abolished in people who consume caffeine daily. For habitual consumers, it’s unlikely that early caffeine consumption will interfere with the cortisol awakening response.

So what’s the recommendation then?

Currently, there’s no science-backed reason to delay your morning caffeine intake.

What we can say is the following:

• It makes sense to limit caffeine intake after noon, especially if you have sleep issues. Caffeine’s half-life is 5-6 hours (meaning half of it remains in the body after that period), and it can take about 24 hours to completely leave the system.

• Before caffeine, hydrate with water first thing in the morning to replenish fluids.

• Listen to your body: if immediate caffeine intake makes you jittery or anxious, test different delays and how they affect you.

Bottom line: If you enjoy your morning coffee right away and it doesn't cause jitters or sleep problems later, there's no compelling scientific reason to delay it.

P.S.: If you want more science-backed information on how to optimize your mornings, the Neuroscience-Optimized Morning Routine will launch very soon.

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No 5 AM wake-ups. No guilt. Just evidence-based strategies that reduce morning anxiety and set a calm tone for your day so you can be successful and productive. Made by a real neuroscientist with 20+ years in research and teaching, not some random internet guru.

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That’s it for today!

And now?

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Until next time!

Best wishes,

Patricia (Dr. Schmidt) from creatorschmidt.com