What are two signs that you’ve had too much caffeine?

Direct Answer: I get these most often from readers 1. “Jitteriness.”2. “Insomnia.” There are two clinically useful indicators that you have passed your own personal caffeine threshold: The Tired-Wired Paradox (fatigue but unable to sleep) and Disproportionate Anxiety (a physiologic head-fuck out of proportion to a stressor)..

Here is a detailed list of symptoms and actionable protocols for different kinds of caffeine consumers.

1. For the “Acute” Symptom Checker

You chugged a huge cold brew or double energy drink, and now you’re feeling it.

The Two Signs:

• Visceral Awareness of the Heartbeat: Your heart not only races, but you can feel it thump in your throat or ears while at rest.
• The Feeling of ‘Doom’: A sudden psychological fear or sense that something bad is about to happen, even though it’s an emotional feeling and not an actual trigger.

The “Flush and Balance” Protocol:

The standard advice is “drink water” — but that is woefully incomplete. Dilution alone will not correct the electrolyte shift created by caffeine’s diuretic effect.

• Stop Drinking Now: Set the cup aside. Don’t complete it “so it doesn’t go to waste.”
• Sodium Water Hydration: Consume 16–24 oz of water with a pinch of sea salt or an electrolyte packet. Caffeine makes your kidneys off-load sodium, dehydrating you; replacing that helps stabilize your heart rate faster than water alone can.
• The L-Theanine Antidote: If you can find any green tea or have access to L-Theanine supplements then take 100-200mg. L-Theanine: is an amino acid from green tea that crosses the blood brain barrier and increases alpha brain waves, which induces a feeling of calm and relaxation without drowsiness. It is a chemical “brake” to caffeine’s “accelerator.”
• Metabolic Walking: Don’t sit and try to meditate; your adrenaline is too high. Engage in light walking. This will help your metabolism digest the caffeine more quickly than if you remained sitting.

2. For the High Achiever Worker & Student

From 8 in the morning until eight at night, you run on coffee.

The Two Signs:

• You drink coffee and within a half-hour you are sleepier, or you wake up in the morning feeling like you have a hangover even though you didn’t party the night before.
• Emotional Volatility: You have zero tolerance for patience. Small annoyances (such as a sluggish website) lead to an irrational level of rage.

The Logic:

Caffeine does not give you energy; it lends it. It does this by blocking adenosine receptors in the brain. Adenosine is the chemical that makes you sleepy. When there’s no caffeine to block the receptors, adenosine pours into the brain and it locks on, making you drowsy. When the caffeine recedes, it is as if the dam bursts and you are hit by colossal fatigue.

The “90-Minute Delay” Strategy:

• Morning Delay: Do not consume caffeine for 90 minutes upon waking. By the time you awaken, your cortisol levels (your natural wake-up hormone) are at their peak. When caffeine is introduced, tolerance and anxiety are heightened.
• Give It Clearance: By waiting 90 minutes, you will be giving your body enough time to clear out the extra adenosine from sleep.
• Taper, Rather Than Quit: If you’re feeling the backswing, taper off use by 20% every three days rather than quit cold turkey that leaves your productivity sprawled out in the snow.

3. For the Health Nut (Pre-Workout Addicts)

You take powders and supplements to get the most out of your workout routine.

The Two Signs:

• Shivers vs. Sweat: A good workout makes you hot. Over-exposure to caffeine results in cold, clammy skin as it’s vasoconstrictive (blood vessels constrict), which reduces the flow of blood at the surface of the skin.
• No. 2 Woe: Needing Gastrointestinal relief during a set “You have to poop NOW!” Caffeine energizes the colon’s smooth muscle; large quantities of it in pre-workouts can incite chaotic digestive behavior.

The Performance Calculation:

A lot of pre-workouts have 300mg+ of anhydrous caffeine (a highly concentrated powder).

• Know Your Limit: The sweet spot for real sports performance enhancement peaks between 3mg and 6mg per kg body weight. That anything over 420mg is providing lesser physical returns and more side effects for a person who weighs 70kg (154lb).
• Check the “Proprietary Blend”: If your supplement has a “Energy Matrix” or “Proprietary Blend” without specifying the precise milligrams of caffeine — discard it. If you can’t measure, you can’t dose.
• Cycle Off: In order to ensure that you’re sensitive to it, cycle off from caffeine free pre workouts for a week each month.

4. Sensitive & Genetic “Slow Metabolizer” Types

You have a cup at noon and can’t fall asleep at midnight.

The Two Signs:

• The 10-Hour ​Jitter: You’re “still wired” or you are anxious 8 to 10 hours after you have had it.
• Distributed Sleep Architecture: You can go to sleep, but wake up repeatedly or not refreshed. This suggests that caffeine is disrupting Deep Sleep (SWS), even if it didn’t prevent you from falling asleep.

The Genetic Context:

This is not “tolerance” in a willpower sense; it is biological. The enzyme that metabolizes caffeine in the liver is CYP1A2.

The “Personal Half-Life” Protocol:

• Know Your Speed: If you have the “slow” version of the CYP1A2 gene, your caffeine half-life (the time it takes to metabolize and eliminate 50% of the drug) can stretch up to 10 hours.
• Noon Cutoff: Stringent rule: No caffeine after noon.
• Trade Down On Variables: Nix dripped coffee, which varies widely depending on bean variety and the length of the brew. Switch to espressos, where the dose is more standardised (roughly 63 mg per shot) and you can factor in this variable.

5. For Energy Drink Drinkers & Parents

Drinking factory-made drinks like Monster, Red Bull, or Prime Energy.

The Two Signs:

• The Sugar-Caffeine Crash Loop: An unparalleled cycle of hyperactivity and then being dead to the world along with super cranky. This is the cascading combination of insulin spiking due to sugar and adenosine rushing in after caffeine crashes.
• “Widow Tics”: In young or small patients, overdose can present as an involuntary twitch of the eyelid or finger.

The Label Literacy Method:

• Size Scam: Check the can. Tend to the can size, many are labeled “2 Servings.” If the label says “150mg per serving,” drinking the whole can gives you a total of 300mg.
• The “Guarana” Multiplier: Check the ingredients for Guarana. It has double the caffeine found in coffee beans. Caffeine content is often cited independently, so the total caffeine is more than the big number on the front says.
• Hard Cap: Zero for kids, according to the American Academy of Pediatrics, but if we’re being honest real life shouldn’t allow more than 100mg a day.

Frequently Asked Questions

What is actually the medically important indications I couldn’t satisfy my caffeine restrict?

In addition to the usual suspicion over-reaction, it’s two big signals are “The Tired-Wired Paradox” (exhausted but can’t sleep) and “Disproportionate Anxiety” (noticeable physiological ‘fight or flight’ responses to relatively minor events).

What should I do right away if I feel “doom” or a racing heart after ingesting caffeine?

Discontinue immediately and drink water with a pinch of salt mixed in or even an electrolyte beverage to fix the osmotic imbalance that caffeine has caused your kidneys. Also, 100-200mg of L-Theanine as a chemical “brake” and oh yeah… some metabolic walking in lieu of sitting still.

Why do I fall asleep or become irritable soon after having coffee?

It is called “Adenosine Backlash.” Caffeine doesn’t flush adenosine from the brain’s receptors so much as jam it up, by impersonating the neurotransmitter that reports fatigue to those receptors. After the caffeine is metabolized, all that pooled adenosine washes over your brain and you experience a crash, with mood swings.

What is the best time to drink caffeine so it does not crash?

After you wake up, wait at least 90 minutes before consuming any caffeine. This way, you’re letting the sleep-induced adenosine in your system clear and allowing your normal levels of cortisol to return, which helps prevent increased tolerance and anxiety.

What is the effective dose of caffeine on workout performance?

The maximum limit for sports performance enhancement is between 3 to 6mg per kg body mass (around 420mg for an individual weighing in at 154lb). It’s at a higher dose than all but the last, and taking more will give you progressively fewer benefits (which is one reason it’s so popular as a recreational drug), along with increased risk of side-effects like cold sweats and an upset stomach.

References

Reference regarding Safe Upper Limits:

• Organization: U.S. Food and Drug Administration (FDA).
• Subject: Spilling the Beans: What’s the Deal with Caffeine?
• Outcome: Refers to 400 milligrams per day — the equivalent of about four or five cups of coffee — as a dose that isn’t commonly linked with harmful, adverse effects in healthy adults.

Refs on The L-Theanine, Caffeine Synergy:

• Entity: Biological Psychology (Journal).
• Submitted): Giesbrecht, T., et al.
• Year: 2010.
• Purpose: L-theanine, a type of amino acid, has been shown to benefit behavior and mental health; however, the effects of the combination of L-theanine and caffeine on cognition have not been examined in detail.
• Result: The study concluded that a combination of ingredients enhanced accuracy and speed on attention-switching tasks and decreased susceptibility to irrelevant information versus caffeine alone.

Read about Caffeine and Adenosine Mechanisms here:

• Source: Journal of Alzheimer’s Disease.
• Authors: Ribeiro, J.A., and Sebastião, A.M.
• Year: 2010.
• Subject: Caffeine and Adenosine.
• Finding: Described that antagonist action on adenosine receptors (A1 and A2A) is the major effect of caffeine to increase wakefulness.

Reference regarding Genetic Metabolism (CYP1A2):

• Source: Journal of the American Medical Association (JAMA).
• Source: Authors: Cornelis, M.C., et al.
• Year: 2006.
• Topic: Coffee, CYP1A2 Genotype and Risk of Myocardial Infarction.
• Outcome: Those with the “slow” *1F allele of the CYP1A2 gene clear caffeine more slowly and are at increased risk of nonfatal heart attacks with high coffee consumption, while a “fast” metabolism doesn’t.

Reference regarding Sports Performance Dosage:

• Source: Journal of the International Society of Sports Nutrition.
• TITLE * Authors: Goldstein, E.R., et al.
• Year: 2010 (Revised 2021 position stand).
• Title: International society of sports nutrition position stand: caffeine and performance.
• Implication: It is now well accepted that caffeine enhances sport performance in moderate doses (3-6 mg.kg) and that higher doses (>= 9 mg.kg) do not induce any further enhancement but increase the chances of side effects.