When Should You Have Your Last Cup of Coffee?
- Fysiobasen
- Nov 21
- 3 min read
Coffee is one of the world’s most popular beverages — loved for its taste, social culture, and energizing effects.
But caffeine has a downside: it can interfere with sleep, disrupt circadian rhythm, and affect your body’s natural recovery.
The timing of your last cup plays a major role in how well you sleep. So — when is it actually too late for coffee?
What Is Caffeine and How Does It Work?
Caffeine is a central nervous system stimulant naturally found in coffee, tea, cocoa, and energy drinks.
It works by blocking adenosine receptors in the brain.Adenosine is a chemical that builds up throughout the day and promotes tiredness.When caffeine blocks it, sleep pressure decreases — and you feel more awake¹.
Caffeine also increases levels of dopamine and adrenaline, raising alertness, heart rate, and physical performance.
Benefits of Caffeine (in Moderation)
Enhances concentration and reaction time
Improves physical endurance
Reduces fatigue and mental exhaustion
May lower risk of Parkinson’s disease and type 2 diabetes²
Drawbacks and Side Effects
Too much caffeine — or consuming it too late — can lead to:
Difficulty falling asleep
Restlessness and anxiety
Increased heart rate and blood pressure
Dependence and withdrawal symptoms when stopping³
When Should You Stop Drinking Coffee for Good Sleep?
A general rule of thumb: avoid caffeine at least 6–8 hours before bedtime.
Caffeine has a half-life of about 5–7 hours, meaning your body takes that long to eliminate half of it⁴.So if you drink coffee at 5:00 p.m., caffeine can still be active in your system close to midnight.
Bedtime | Latest Caffeine Intake |
10:00 p.m. | 2:00–4:00 p.m. |
11:00 p.m. | 3:00–5:00 p.m. |
12:00 a.m. | 4:00–6:00 p.m. |
What Affects How Long Caffeine Lasts?
Genetics
People metabolize caffeine differently.Those with certain liver enzyme variants (CYP1A2 gene) break it down slower⁵ — making caffeine’s effects last longer.
Age and Hormones
Caffeine metabolism slows with age, and hormonal changes (such as birth control or pregnancy) can prolong its presence in the body.
Sleep Quality and Pressure
The less you’ve slept, the stronger caffeine feels — but also the more it disrupts your next night’s sleep.
Tolerance
Regular coffee drinkers may build tolerance, but sleep quality still declines, even if you no longer “feel” the alertness⁶.
How Late Coffee Affects Sleep
Even one cup in the evening can:
Delay sleep onset
Shorten total sleep time
Reduce deep slow-wave sleep (N3)
Lower perceived sleep quality
Studies show caffeine taken 3–6 hours before bed still significantly reduces sleep duration and depth⁷.
Healthier Evening Alternatives
Decaffeinated coffee: Similar taste, minimal caffeine impact
Herbal tea: Chamomile, lemon balm, or rooibos promote relaxation
Warm milk or oat milk: Naturally rich in tryptophan, a sleep-promoting amino acid
Water with herbs or citrus: Refreshing and caffeine-free
Summary
Caffeine stays active in your system for hours — often longer than you think.
For optimal sleep, avoid coffee 6–8 hours before bedtime.Adjust your timing based on your usual sleep schedule, metabolism, and caffeine sensitivity.
Good sleep often starts with smart choices earlier in the day — including what’s in your cup.
Sources
Fredholm BB, et al. (1999). Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev, 51(1):83–133.
van Dam RM, Hu FB. (2005). Coffee consumption and risk of type 2 diabetes: a systematic review. JAMA, 294(1):97–104.
Juliano LM, Griffiths RR. (2004). A critical review of caffeine withdrawal. Psychopharmacology, 176(1):1–29.
Institute of Medicine. (2001). Caffeine for the Sustainment of Mental Task Performance. National Academies Press.
Sachse C, et al. (1999). Functional significance of a polymorphism in the CYP1A2 gene tested with caffeine. Br J Clin Pharmacol, 47(4):445–449.
Drake C, et al. (2013). Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. J Clin Sleep Med, 9(11):1195–1200.
Clark I, Landolt HP. (2017). Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials. Sleep Med Rev, 31:70–78.
