Coffee Side Effects: Anxiety, Sleep, Jitters, Dependence, and Individual Sensitivity
Author: Ukrainian Psychological Hub · Published: September 28, 2026 · Editorial Policy
Coffee can cause side effects, but the phrase “coffee side effects” covers several different mechanisms. The most common unwanted effects are jitters, restlessness, anxiety, sleep disruption, a faster or more noticeable heartbeat, temporary blood-pressure changes, stomach upset, nausea, headache, and bowel urgency. With regular caffeine use, tolerance, physical dependence, and withdrawal can also occur. The U.S. Food and Drug Administration lists increased heart rate, palpitations, high blood pressure, insomnia or sleep disruption, anxiety, jitters, upset stomach, nausea, and headache among signs that caffeine intake may be too high for a particular person.
Coffee itself is a complex beverage; caffeine is one psychoactive component of it. Many side effects people attribute to coffee are primarily caffeine effects, while some digestive responses can occur with decaffeinated coffee as well. That distinction matters because changing the dose, serving size, timing, brew, or switching to decaf can change the experience without changing the fact that the beverage is still coffee.
There is no single number of cups that predicts side effects for everyone. For most healthy adults, the FDA cites 400 mg of caffeine per day as an amount not generally associated with negative effects, while emphasizing wide variation in sensitivity and elimination. EFSA’s caffeine safety assessment similarly concludes that up to 400 mg per day does not raise safety concerns for healthy adults in the general population, but also notes that a single 100 mg dose may affect sleep in some adults when taken close to bedtime. A population-level safety limit is therefore not a personal symptom threshold.
Coffee side effects: the short answer
If coffee makes you feel shaky, wired, anxious, nauseated, unable to sleep, or unusually aware of your heartbeat, caffeine dose and individual sensitivity are the first variables to examine. The same cup can feel mild to one person and excessive to another because “one coffee” is not a standardized dose and because caffeine pharmacokinetics, habitual use, genetics, medications, pregnancy, smoking status, sleep, and anxiety sensitivity differ between people.
The most useful way to think about coffee side effects is to separate five questions: how much caffeine was actually consumed; how quickly it was consumed; when it was consumed; what the person’s current sensitivity and tolerance are; and whether the symptom is caused mainly by caffeine, another component of coffee, or something that merely happened at the same time.
• Jitters and shakiness: usually an acute stimulant effect that becomes more likely as dose exceeds personal tolerance.
• Anxiety or nervousness: supported by experimental and review evidence, with stronger effects at higher doses and substantial person-to-person variation.
• Sleep disruption: one of the best-established caffeine effects; timing matters as much as total daily intake.
• Palpitations or a faster heartbeat: can occur subjectively, but feeling palpitations is not the same as having a dangerous arrhythmia.
• Stomach upset, nausea, reflux symptoms, or bowel urgency: can involve caffeine and non-caffeine coffee components.
• Headache: may occur with high intake, but headache is also a classic caffeine-withdrawal symptom after regular use.
• Tolerance, dependence, and withdrawal: pharmacologically real phenomena that should be distinguished from the casual phrase “coffee addiction.”
Why coffee can produce side effects
Caffeine blocks adenosine signaling
At ordinary human consumption levels, caffeine’s central pharmacological action is primarily antagonism of adenosine receptors. Adenosine participates in sleep pressure and neural regulation; blocking its receptors reduces the signaling that normally favors sleepiness and restraint of neural activity. Fredholm’s pharmacological review concluded that adenosine-receptor blockade is the mechanism relevant at concentrations reached during normal human caffeine consumption.
That mechanism explains why the desired and undesired effects are closely related. More alertness can become restlessness; greater arousal can become jitteriness; delayed sleepiness can become insomnia. The dividing line is not a categorical switch between “benefit” and “side effect.” It depends on dose, timing, task, prior sleep, tolerance, and the person experiencing the effect.
A cup is not a dose
The word “cup” is a poor pharmacological unit. The FDA gives a typical range of 113–247 mg of caffeine for a 12-fluid-ounce regular brewed non-specialty coffee, and actual products can vary outside simple averages. Espresso may be more concentrated per milliliter while a larger brewed coffee can contain more total caffeine per serving. For a detailed dose guide, see How Much Caffeine Is in Coffee?.
This is also why “strong coffee” is ambiguous. A coffee can taste intense while containing less total caffeine than a larger, milder-tasting drink. Roast darkness, bitterness, body, caffeine concentration, and total caffeine per serving are different variables.
Coffee is more than caffeine
Coffee contains many compounds besides caffeine, and the beverage can affect the gastrointestinal tract through mechanisms that are not reducible to caffeine alone. In a small human study, regular and decaffeinated coffee both increased distal-colon motor activity in responders, while hot water did not. Brown, Cann, and Read’s manometry study is one reason bowel urgency after coffee should not automatically be described as a pure caffeine effect.
Jitters, shakiness, restlessness, and the “wired” feeling
Coffee jitters are a cluster of stimulant sensations rather than a single diagnosis. People may describe fine hand tremor, muscle tension, internal shakiness, restlessness, difficulty sitting still, rapid speech, heightened bodily awareness, or the sense of being mentally overactivated. The FDA explicitly lists jitters among signs of too much caffeine for an individual.
Jitters are more likely when the dose is high relative to your tolerance, when several caffeinated products are combined, or when caffeine is consumed rapidly. They can also feel stronger after a period of reduced caffeine use because tolerance is lower. A person who drinks coffee daily and a person who rarely consumes caffeine can therefore have very different responses to the same measured dose.
Feeling jittery does not tell you exactly how many milligrams you consumed, and it does not by itself diagnose an anxiety disorder, heart problem, or caffeine-use disorder. It is evidence that the stimulant effect is noticeable and may have crossed your personal comfort threshold.
Coffee and anxiety
Caffeine can increase anxiety symptoms in healthy people, and the effect is dose-sensitive. A 2024 meta-analysis found greater anxiety after caffeine exposure overall and a larger effect in higher-dose studies. Liu and colleagues’ meta-analysis included 546 participants across 14 study samples. A newer 2026 systematic review of 27 studies likewise concluded that the evidence predominantly supports a dose-dependent anxiogenic effect, while noting differences between people with lower and higher habitual caffeine intake.
The important distinction is between an acute caffeine effect and an anxiety disorder. Caffeine can produce bodily sensations that resemble anxiety—tremor, restlessness, a racing or pounding heart, gastrointestinal discomfort, increased vigilance—without establishing a psychiatric diagnosis. In some people, those sensations are also interpreted as threatening, which can amplify the subjective experience.
People with panic disorder appear especially sensitive to high-dose caffeine challenge paradigms. A systematic review and meta-analysis of caffeine challenge studies found markedly greater panic responses in patients with panic disorder than in healthy controls, although many classic challenge studies used doses far above a small everyday coffee. More recent evidence adds nuance: a 2025 randomized crossover trial using 150 mg caffeine did not reproduce the dramatic high-dose challenge pattern.
For the full anxiety-specific evidence, use our dedicated guides to coffee and anxiety, caffeine and anxiety, and coffee and panic attacks. This side-effects page keeps the broader question in view: anxiety is one possible response to coffee, not a universal consequence.
Coffee and sleep disruption
Sleep disruption is among the most consistently demonstrated caffeine side effects. Caffeine can delay sleep onset, shorten total sleep time, reduce sleep efficiency, and alter sleep architecture. A 2023 systematic review and meta-analysis found significant worsening across several sleep outcomes, and a 2025 meta-analysis of 22 controlled crossover trials reported an average reduction in total sleep time of about 35 minutes, an increase in sleep-onset latency of about 8 minutes, and lower sleep efficiency.
Those averages do not mean every person loses exactly 35 minutes. Sleep effects depend on dose, clock time, habitual intake, genetics, and elimination rate. EFSA notes that even a 100 mg dose may alter sleep duration and patterns in some adults when consumed close to bedtime.
A randomized case-crossover trial in 100 ambulatory adults also found that days assigned to caffeinated coffee were associated with about 36 fewer minutes of nightly sleep than days assigned to caffeine avoidance. The CRAVE trial is especially useful because it studied coffee consumption in everyday life rather than caffeine capsules alone.
Sleep creates a feedback loop with coffee use. Caffeine can make it easier to function after insufficient sleep, but late or excessive caffeine can then reduce subsequent sleep, increasing the next day’s fatigue and the temptation to use more caffeine. The pharmacological effect and the learned routine can therefore reinforce each other without implying that every daily coffee habit is pathological.
For timing-specific guidance, see Coffee and Sleep and How Long Before Bed Should You Stop Drinking Coffee?.
Heart rate, palpitations, and blood pressure
Caffeine can make the cardiovascular system feel more noticeable. The FDA lists increased heart rate, heart palpitations, and high blood pressure among possible signs of excessive intake. A meta-analysis of randomized trials of caffeine supplementation found small average increases in systolic and diastolic blood pressure. The 2023 systematic review and dose-response meta-analysis estimated pooled increases of roughly 1.9 mmHg systolic and 1.7 mmHg diastolic, while emphasizing dose and study differences.
Palpitations, however, are a sensation; arrhythmia is an electrical diagnosis. The two should not be treated as synonyms. In the CRAVE randomized trial, caffeinated coffee did not significantly increase premature atrial contractions, although premature ventricular contractions were more frequent on coffee-assigned days. Population-level observational evidence is also more complicated than the popular claim that coffee simply “causes arrhythmias.” A 2026 systematic review and meta-analysis of incident atrial fibrillation found no increased atrial-fibrillation risk at higher categories of daily coffee intake.
The practical implication is precision: coffee can cause a pounding-heart sensation or measurable short-term cardiovascular changes in some people, while the evidence does not justify treating ordinary coffee consumption as a universal cause of clinically important arrhythmia. New, severe, sustained, or unexplained cardiovascular symptoms deserve medical evaluation rather than interpretation through a coffee article alone.
Stomach upset, nausea, reflux, and bowel urgency
Coffee can affect the digestive tract in several ways. Some people notice nausea, upper-abdominal discomfort, reflux symptoms, or a rapid urge to have a bowel movement. The FDA includes upset stomach and nausea among signs of excessive caffeine intake, but coffee-specific gastrointestinal effects are not always caused by caffeine.
Bowel urgency is a clear example. In a small manometry study, both regular and decaffeinated coffee increased rectosigmoid motor activity in people who reported a coffee-related urge to defecate. That finding supports a coffee effect that extends beyond caffeine alone.
Reflux is more uncertain than many popular articles imply. Earlier studies were inconsistent. A large 2026 systematic review and meta-analysis of 40 studies found a small association between coffee use and GERD (odds ratio 1.18) but with very high heterogeneity, and the authors described the clinical significance as unclear. That does not support a rule that everyone with reflux must avoid coffee; it supports individualized attention to reproducible symptoms.
Drinking coffee on an empty stomach is often blamed for every unpleasant coffee reaction, but the evidence is more specific than the myth. Food does not reliably neutralize caffeine, and many symptoms depend more strongly on total dose and sensitivity. If fasting coffee reliably produces nausea, shakiness, or discomfort for you, changing the context may still be useful. Our dedicated article on coffee on an empty stomach separates evidence from common assumptions.
Headache: coffee can be involved in more than one way
Headache after coffee can have different explanations. High or poorly tolerated caffeine intake can coincide with headache, and the FDA includes headache among signs of excessive caffeine consumption. But headache is also the best-established symptom of caffeine withdrawal. These are opposite exposure patterns, so the timing of habitual intake matters.
A person who normally drinks coffee every morning may develop a headache after delaying or skipping it. A person who rarely consumes caffeine may instead get a headache after an unusually large dose. A third person may have a primary headache disorder whose relationship with caffeine is more complex. The symptom alone does not identify the mechanism.
If headache appears after reducing regular caffeine, see our evidence-based guide to caffeine withdrawal.
Tolerance, dependence, withdrawal, and “coffee addiction”
Regular caffeine use can produce tolerance to some effects, physical dependence, and a recognizable withdrawal syndrome. These concepts are related but not interchangeable.
Tolerance
Tolerance means that the same dose produces a smaller effect after repeated exposure. It can help explain why a long-term coffee drinker can consume a dose that makes a low-frequency user feel intensely jittery. Tolerance is effect-specific and incomplete; it does not mean caffeine has stopped acting. See Caffeine Tolerance for the dedicated evidence review.
Physical dependence
Physical dependence means the nervous system has adapted to repeated caffeine exposure such that reducing or stopping it can produce withdrawal. Dependence can occur without the compulsive behavioral pattern people often mean by “addiction.” Addicott’s review of caffeine-related disorders emphasizes that some users develop clinically meaningful dependence, while the prevalence and severity of more problematic caffeine use are less certain.
For the terminology and clinical distinctions, see Caffeine Dependence: Tolerance, Withdrawal, and How It Differs From Coffee Addiction.
Withdrawal
A comprehensive review of experimental studies found that caffeine withdrawal typically begins 12–24 hours after abstinence, peaks around 20–51 hours, and lasts about 2–9 days. Validated symptoms include headache, fatigue, reduced energy and alertness, drowsiness, depressed mood, difficulty concentrating, irritability, and feeling foggy; nausea and muscle symptoms can also occur. Juliano and Griffiths’ critical review also found that withdrawal can occur after daily doses as low as 100 mg in some people.
This is why abruptly stopping coffee can feel worse before it feels better. It is also why a morning coffee can appear to provide a large “boost” in a habitual user when part of the change may be reversal of overnight withdrawal. The subjective benefit is real; the mechanism can include both stimulation and withdrawal relief.
Why the same coffee affects people differently
Total caffeine dose and speed of consumption
The same beverage consumed slowly over an hour and rapidly in several minutes can produce different subjective peaks. Total caffeine from the entire day also matters: coffee, tea, cola, energy drinks, chocolate, supplements, and some medications can all contribute. The FDA advises counting caffeine across sources rather than judging coffee in isolation.
Metabolism and medications
Caffeine is metabolized primarily through hepatic CYP1A2, and its pharmacokinetics vary widely. A systematic analysis of data from 141 publications documented differences associated with smoking, oral contraceptives, disease states, and drug interactions. Grzegorzewski and colleagues’ pharmacokinetic analysis is a reminder that “how long caffeine lasts” is a distribution across people and contexts, not a single universal half-life.
Genetic differences in metabolism and sensitivity
Genetic variation can contribute to differences in both caffeine metabolism and brain response. A 2023 systematic review of caffeine genetics and brain-related outcomes found evidence that CYP1A2 variation may modify some cognitive responses and that ADORA2A variation may influence anxiety and sleep responses. These effects are probabilistic, not a consumer-grade genetic test that can declare a person “safe” or “sensitive” from one variant.
Habitual intake and tolerance
People who consume caffeine frequently may show less subjective stimulation from a familiar dose than low-frequency users. When intake is reduced, tolerance can partly reverse. This is one reason an old coffee routine can suddenly feel different after illness, travel, a break from caffeine, or a change in daily habits.
Sleep debt and current arousal state
The same caffeine dose can feel different after a full night of sleep versus severe sleep restriction. Sleep loss raises the value of caffeine as an alertness aid, while also increasing the risk that later caffeine perpetuates the sleep-loss cycle. Stress and high baseline arousal can similarly make ordinary stimulant sensations feel more intrusive.
Pregnancy and other situations requiring different limits
General adult guidance should not be applied mechanically to pregnancy. EFSA concludes that caffeine from all sources up to 200 mg per day does not raise safety concerns for the fetus, and ACOG’s guidance states that moderate caffeine consumption below 200 mg per day does not appear to be a major contributor to miscarriage or preterm birth. People who are pregnant, breastfeeding, taking medications, or managing medical conditions may need individualized guidance.
Decaf coffee can still cause some coffee-related effects
Decaf is not caffeine-free. The FDA reports that decaffeinated coffee typically contains about 2–15 mg of caffeine per 8-fluid-ounce cup. For many caffeine-sensitive people, switching from regular coffee to decaf dramatically reduces stimulant exposure, but a person who reacts to very small doses or drinks many servings can still receive caffeine.
Decaf also retains many non-caffeine coffee compounds, which is why it can still produce taste, aroma, ritual, acid-related sensations, or bowel responses. If a symptom disappears with decaf, caffeine becomes a stronger suspect. If it remains reproducible with both regular and decaf, caffeine is less likely to be the only mechanism.
How much coffee is too much? Dose limits and symptom limits are different
For most healthy adults, 400 mg of caffeine per day is the widely cited FDA reference amount that is not generally associated with negative effects. EFSA also identifies up to 400 mg per day as not raising safety concerns for healthy adults, and up to 200 mg as a single dose that does not raise safety concerns in that population. These are safety assessments, not performance targets and not guarantees of zero symptoms.
A person can experience anxiety, insomnia, tremor, palpitations, or stomach symptoms below 400 mg. EFSA explicitly notes that 100 mg near bedtime may alter sleep in some adults. Conversely, exceeding 400 mg does not mean a specific adverse event will occur. The correct interpretation is that risk and side effects are dose-dependent and individually variable.
A major systematic review of caffeine safety evaluated hundreds of studies and found that the overall evidence supported 400 mg/day as a level not associated with overt adverse effects in healthy adults, while also highlighting sensitive populations and interindividual variability. Wikoff and colleagues’ systematic review should be read alongside the FDA and EFSA guidance rather than converted into a universal personal prescription.
How to reduce coffee side effects without necessarily giving up coffee
The most effective strategy is usually to change the variable that actually causes the problem. For caffeine-driven symptoms, that means reducing caffeine exposure or changing timing rather than trying to “cancel out” caffeine with another ingredient.
• Measure the caffeine problem, not just the cup count. Check serving size and product information when available, and remember that café drinks can vary substantially.
• Reduce the size or strength of the caffeinated portion. A smaller regular coffee, half-caf, or decaf can preserve flavor and ritual with less caffeine.
• Move caffeine earlier when sleep is the problem. Timing can matter even when total daily intake looks moderate.
• Avoid stacking caffeine sources. Coffee plus energy drinks, pre-workout products, tea, cola, chocolate, or medication can make the total dose easy to underestimate.
• If you are a daily user and want to reduce substantially, tapering is often more comfortable than abrupt cessation because it lowers the chance of withdrawal headache, fatigue, and irritability. The FDA also advises gradual reduction.
• Treat reproducible symptoms as useful data. If a certain dose repeatedly causes jitters, anxiety, palpitations, nausea, or insomnia, your personal threshold may be lower than a population-level safety ceiling.
Food, hydration, breathing exercises, or a walk may change how someone feels in the moment, but none of them chemically removes caffeine from the bloodstream. The most reliable preventive variables are dose, timing, frequency, and choice of caffeinated versus decaffeinated coffee.
When coffee symptoms should not be dismissed as “just caffeine”
Common coffee side effects are usually transient, but a familiar explanation should not become a reason to ignore severe or unusual symptoms. New chest pain, fainting, severe shortness of breath, a sustained or clearly irregular rapid heartbeat, seizure, severe agitation, repeated vomiting, or other intense symptoms require appropriate medical assessment. Pure or highly concentrated caffeine products are especially different from ordinary coffee: the FDA warns that rapid consumption of high doses can produce toxic effects including seizures and that concentrated caffeine products can be dangerous.
Likewise, a sudden change in caffeine tolerance can have explanations beyond the coffee itself, including medication changes, pregnancy, changes in smoking status, illness, or altered sleep. A coffee diary can help establish a pattern, but it cannot diagnose the cause of unexplained symptoms.
The psychology of coffee side effects
Coffee side effects are physical events and interpreted experiences at the same time. Caffeine can change arousal; the brain also interprets what that arousal means. A pounding heart before a presentation may be labeled “energy,” “excitement,” or “anxiety” depending on context, expectation, previous experience, and perceived control. This does not make the physiological response imaginary. It explains why the same measurable arousal can feel different across situations.
Expectation can also shape symptom monitoring. A person who has previously had a frightening episode after coffee may scan for heartbeat, tremor, or stomach sensations the next time they drink it. Greater attention can make sensations more salient, while the caffeine itself is still producing a genuine pharmacological effect. The useful distinction is between the physiological trigger, the perception of bodily change, and the interpretation placed on that change.
This is especially relevant to panic vulnerability, where interoceptive sensations can acquire threat meaning. It is also relevant to habit: the smell, cup, café, time of day, work desk, or social setting can become learned cues for expectation and craving. None of these psychological mechanisms replaces pharmacology; they operate alongside it.
What the evidence shows—and what it does not
Established evidence supports several core conclusions. Caffeine blocks adenosine receptors at ordinary consumption levels. It can disrupt sleep, increase anxiety in a dose-dependent way, produce jitters and other stimulant symptoms, cause physical dependence and withdrawal with regular use, and produce short-term cardiovascular effects such as modest blood-pressure increases. Coffee can also affect gastrointestinal motility through mechanisms that are not solely caffeine.
Evidence is more qualified for several popular claims. Palpitations after coffee do not prove a dangerous arrhythmia. Coffee is not a universal cause of GERD, although a small association appears in recent pooled observational data. Feeling calm or sleepy after caffeine does not diagnose ADHD. A dark roast is not automatically “stronger” pharmacologically. Milk does not remove caffeine. Eating before coffee may change comfort for some people but does not erase the caffeine dose.
Long-term observational coffee research also cannot be used to predict an individual’s acute side-effect threshold. People who choose to drink coffee differ from non-drinkers in many ways, and people who are highly sensitive may self-select into lower consumption. Acute randomized caffeine studies answer a different question from cohort studies of habitual coffee intake. The strongest interpretation comes from keeping those evidence types separate.
Frequently asked questions
What are the most common side effects of coffee?
The most commonly recognized unwanted effects include jitters, nervousness or anxiety, sleep disruption, palpitations or a faster heartbeat, temporary blood-pressure increases, stomach upset, nausea, headache, and bowel urgency. With regular caffeine use, tolerance, dependence, and withdrawal can also occur. Which effects appear depends strongly on dose and sensitivity.
Why does coffee make me jittery?
Usually because the caffeine dose produces more central nervous system arousal than is comfortable for you at that moment. Low tolerance, rapid consumption, large servings, multiple caffeine sources, sleep deprivation, and anxiety sensitivity can all make the same dose feel stronger.
Can coffee cause anxiety?
Yes. Controlled studies and systematic reviews support an anxiogenic effect of caffeine, especially at higher doses, but the effect varies substantially between people. Feeling anxious after coffee does not by itself diagnose an anxiety disorder.
Can coffee cause a panic attack?
High-dose caffeine challenges can provoke panic attacks in people with panic disorder more readily than in healthy controls. Everyday coffee doses are highly variable, and lower-dose evidence is more nuanced. Panic-like symptoms after coffee should therefore be interpreted by dose, vulnerability, and clinical context rather than by a universal rule.
How long do coffee side effects last?
There is no single duration. It depends on caffeine dose, absorption, metabolism, habitual use, medications, smoking status, pregnancy, and the symptom being measured. Caffeine can remain biologically active for many hours, so sleep effects may outlast the obvious “buzz.”
Can one cup of coffee cause side effects?
Yes. “One cup” can contain very different amounts of caffeine, and some people are sensitive at doses that are well below general adult safety limits. The dose in the cup and the person’s response matter more than the cup count.
Does decaf coffee have side effects?
It can. Decaf usually contains a small amount of caffeine and retains non-caffeine coffee compounds. It is less likely to produce strong caffeine-driven jitters or insomnia, but it can still produce digestive or sensory effects in some people.
Does coffee raise blood pressure?
Caffeine can cause a modest short-term rise in blood pressure on average, although the response varies and tolerance may modify it. A single reading after coffee cannot establish chronic hypertension.
Are palpitations from coffee dangerous?
Palpitations are a symptom, not a diagnosis. Coffee can make heartbeat sensations more noticeable, while studies do not show that ordinary coffee universally increases clinically important arrhythmias. Severe, sustained, new, or unexplained palpitations—especially with chest pain, fainting, or shortness of breath—deserve medical evaluation.
Can coffee upset your stomach or make you poop?
Yes. Coffee can stimulate gastrointestinal activity in some people, and this is not entirely a caffeine effect because decaf has also altered colonic motility in human studies. Reflux evidence is mixed, with a recent meta-analysis finding only a small association and substantial heterogeneity.
Can you become dependent on coffee?
Regular caffeine use can produce physical dependence, which means reducing or stopping it may trigger withdrawal. Dependence is not identical to compulsive addiction. Caffeine-use disorder has been studied as a clinically meaningful pattern in a subset of users, while withdrawal is much better established.
What happens if I stop coffee suddenly?
Habitual users may develop caffeine withdrawal, commonly headache, fatigue, drowsiness, reduced alertness, irritability, low mood, and difficulty concentrating. Symptoms often begin within 12–24 hours, peak within roughly the next day or two, and resolve within several days.
Is 400 mg of caffeine safe for everyone?
No single number applies to everyone. The FDA cites 400 mg per day as an amount not generally associated with negative effects for most adults, and EFSA reaches a similar population-level conclusion for healthy adults. Individual side effects can occur at lower doses, and pregnancy, medications, medical conditions, and unusual sensitivity can change the relevant limit.
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