2:00 pm. You have pumped so much work in the morning and already attended three (Zoom) meetings. Now you’re having a bit of ‘me time’, watching the hands of the clock making more movements than you are doing now. You want to get on to that next task but your lids feel so heavy. You feel like staring into blank space for 5 more minutes.
Welcome to the afternoon slump!
Normally you’d make your way to the coffee machine and make another cup of joe. But you suddenly realize that if you do, this would be your fourth cup for the day.
You start to think – how I wish my caffeine fix would last.
The clock continues to tick…
So fleeting! This is how long caffeine lasts
If you’re wondering how long caffeine lasts (and consequently how many trips to the barista you need to take in a day), then here’s the low down.
There are two things to consider: how long caffeine takes to kick in, and how long it could stay in your system.
How long does caffeine take to kick in?
As many of you know, caffeine takes a while to go full-on power mode. Yeah no, it doesn’t work like Popeye’s spinach.
The magic number based on various research appears to be 10-45 minutes.
Researchers from the University of Barcelona in a study published in December 2008 in the journal Progress in Neuro-Psychopharmacology and Biological Psychiatry reported that caffeine hits top speed after about 45 minutes, when 99 percent of the caffeine from your coffee, tea or energy drink has entered the bloodstream fully. Then it takes many hours for the caffeine to dissipate. 
And according to a study featured by Science Daily, alertness does not increase until after 30 or 45 minutes. 
“Forty-five minutes is the time needed for maximum caffeine concentration to be reached in the blood, but levels reach half this concentration after just a few minutes,” Science Daily reports.
How long does caffeine stay in your system?
Now that you know how long the effects of caffeine are felt after that first sip (or mint pop), the next question is how long caffeine actually stays in your system.
According to various reports, the average plasma half-life of caffeine in healthy adults is within the range of 1.5 to 9.5 hours. [3, 4]
The University of Nottingham School of Health Sciences defines half-life as: 
the duration of action of a drug [and the] period of time required for the concentration or amount of drug in the body to be reduced by one-half.
We usually consider the half-life of a drug in relation to the amount of the drug in plasma. A drug’s plasma half-life depends on how quickly the drug is eliminated from the plasma.
While half of the total caffeine dosage consumed get cleared from the body in 5 hours for most people, it normally takes 8.25 hours to 2.18 days to completely rid of the stimulant.
To learn more, read this article: The half-life of caffeine lasts for hours after your last drink.
Now this duration varies from person-to-person, and factors such as age, body type and build, genes, medication, diet (and if it consists of too much caffeine), and many more play a role in how long our caffeine fix could last.
How do you make caffeine last longer
Now the question remains. How do you make your caffeine work for you? How could you make it last so you save more trips to the barista or the coffee machine?
Some people drink coffee throughout the day. Think Friends or the Gilmore Girls where making coffee or hanging out in a café is a big part of every episode. But while this could ensure that you have a constant stream of pick-me-upper in your system, maybe this isn’t making the most bang for your cup.
There’s only so much caffeine you could have in a day. In fact, here’s how much your body can take on a daily basis: 400 mg. That’s 4 cups of brewed coffee, 10 cans of soda, or 2 energy shot drinks. But while that speaks of the capacity, it isn’t likely for any medical professional to recommend that on the regular!
Remember, caffeine could stay in your system for until 9 hours, and if you feel like the effects you’re after easily fades away, then you may be caffeine tolerant. Perhaps revisiting your caffeine consumption is in order.
If you decide to ease off on your caffeine, or be more intentional with your consumption, then here are some slump-saving hacks for you:
Small, frequent doses
Have you tried caffeine microdosing?
A trend in Silicon Valley, microdosing has a become a common practice of ingesting minimal doses of a substance – say one-tenth or one-twentieth of what’s normal. Caffeine microdosing is consuming it in small amount, enough to reap the benefits without the infamous downsides of over-caffeination – jitters, heart palpitations and anxiety.
Timing your caffeine consumption
This is another intentional way of enjoying your caffeine fix and reaping its benefits at the same time.
Find your non-peak times when your cortisol levels are down. Cortisol are your body’s flight-or-fight hormones and keeps you up on your toes.
The best time to take in coffee, then, is when cortisol levels are NOT on their full-on high. This could be mid-morning or in the afternoon before 3 PM (otherwise you may not be able to sleep well at night).
If you’re wondering what cortisol is and its importance with regard to coffee consumption, then read the article “When's the best time to drink coffee?”.
Or maybe have a coffee nap, a cup of joe you drink right before having a power nap. The article “Here’s the best way to drink coffee and stay awake” will tell you why coffee naps are effective and can get you through that sluggish afternoon.
Time-release delivery is a relatively new technology in food science but it doesn’t mean it’s not effective. Sciencemeetsfood.org explains how it works: 
In this delivery system, nutrients are encapsulated in microbeads, and these micro-beads are designed to release the nutrients within gradually in response to the changing pH conditions in the small intestine.
In everyday terms, it means that there’s extended release for the caffeine so it is slowly released over time. This gives you a smooth and steady kick that lasts for hours without the crash.
Products like VALI Time Release Caffeine - Microencapsulated Caffeine gives you a steady energy boost so you can focus, work, and perform your best. It uses microencapsulated caffeine that is a controlled and timed release. The sustained energy over time keeps you alert and gives you a boost without the jittery side effects of typical caffeine products.
Now this hack surely works to avoid caffeine crash and that caffeine taste (if you’re not a fan). But proceed with caution – this may be perfect for early morning meetings that go through the afternoon. But taking these halfway through the day may not be the best idea if you want to get a good night’s sleep.