Caffeine
A bitter central-nervous-system stimulant naturally found in coffee, tea, cacao, and added to foods/drinks to increase alertness.
Should I eat Caffeine?
Caffeine is an effective stimulant with predictable short‑term benefits, but dose and timing determine whether it helps or harms. Most adults do well staying under 400 mg/day and avoiding it near bedtime; pregnancy and youth require lower limits.
Summary
Caffeine occurs naturally in coffee and tea and is also added to many drinks and supplements. Evidence supports clear intake thresholds: about 200 mg per dose and 400 mg/day for most adults, with 200 mg/day advised in pregnancy and roughly 3 mg/kg for youth. Benefits include improved alertness and lower perceived exertion during exercise, but sensitivity varies widely. Main risks are sleep disruption, anxiety, and palpitations, especially at higher doses or in sensitive people; product caffeine content varies, so read labels and count all sources. Purified caffeine is highly refined and often extracted using solvents, though residues are regulated and CO2 processes are available.
Key Research Points
Know your dose (200 mg once, 400 mg/day)
For most healthy adults, single doses up to about 200 mg and total intakes up to 400 mg/day are generally not linked with safety concerns; higher or clustered doses raise the chance of jitters, palpitations, and anxiety. Count caffeine from all sources, including guarana in energy products.
Timing matters for sleep
Caffeine can delay falling asleep and reduce sleep quality; many people do best avoiding it within about 6–8 hours of bedtime.
Special groups need tighter limits
Pregnant or breastfeeding people should keep intake at or below 200 mg/day, and children/adolescents should limit to about 3 mg/kg body weight; in the EU, high-caffeine drinks must carry warnings that they are not recommended for these groups.
Overview
What is it?
Why is it used?
Origin
People have brewed caffeine-containing plants for millennia: tea in China by at least the Tang dynasty, coffee in Yemen/Ethiopia by the 15th century, and cacao in Mesoamerica long before that. Purified anhydrous caffeine became commercially available in the late 1800s; by the early 20th century it was standard in cola drinks in the U.S., and today it is widely added to energy beverages, shots, and performance products.
Process: Extract, isolate, and crystallize (or synthesize)
Steps
Chemicals
Research & Safety
Potential Concerns
Too much caffeine, or doses taken close together, can trigger nervousness, rapid heartbeat, and poor sleep. Timing matters: many people should avoid caffeine within 6–8 hours of bedtime. Purified caffeine is a highly refined ingredient; extraction and decaffeination may use solvents such as methylene chloride or ethyl acetate, though residues in finished products are tightly regulated and CO2 methods avoid these solvents. Energy drinks and shots can contain large amounts per serving, so check labels and count all sources, including guarana.
Potential Benefits
At low to moderate doses, caffeine reliably increases alertness and can speed simple reaction time. Many people also feel workouts are easier and performance modestly improves with caffeine. These effects are short term and dose dependent, with common serving sizes in packaged products ranging from about 50 to 200 mg. Caffeine provides no meaningful calories, vitamins, or minerals—its value is functional, not nutritional.
Digestive Effects
Higher doses can cause nausea, stomach upset, or loose stools in some people. Caffeine can worsen reflux symptoms and may aggravate IBS in sensitive users. It also increases urine output, which some experience as more frequent bathroom trips. These effects are more likely with single doses above about 200 mg or with total intakes over 400 mg/day in adults, and at lower amounts in smaller or sensitive individuals.
Limit Consumption
Pregnant and breastfeeding people are advised to limit caffeine to 200 mg/day to reduce potential risks; EFSA and ACOG support this guidance. Caffeine passes into breastmilk, so watch for infant irritability or sleep changes when maternal intake rises. For children and adolescents, EFSA suggests about 3 mg/kg body weight per day as a conservative limit, and EU labels on high‑caffeine drinks warn they are not recommended for kids or for pregnant or breastfeeding women. People with anxiety disorders, insomnia, GERD, or heart rhythm problems may need lower limits or to avoid caffeine altogether; consult your clinician for personalized advice.
Fact Sheet
Regulatory Status
ESG & Sustainability
Allergens and Diet
Natural Alternatives
Coffee powder (finely ground)
Matcha (green tea powder)
Yerba mate extract
Citations
21 CFR 182.1180 — Caffeine (GRAS in cola-type beverages at 0.02%)
2024-01-01U.S. FDA • eCFR (FDA)
Spilling the Beans: How Much Caffeine is Too Much?
2024-08-28U.S. FDA • FDA Consumer Update
Scientific Opinion on the safety of caffeine
2015-05-27EFSA Panel on Nutrition, Novel Foods and Food Allergens • EFSA Journal
Regulation (EU) No 1169/2011 — food information to consumers (high-caffeine label statement)
2011-11-22European Parliament and Council • EUR-Lex
Moderate Caffeine Consumption During Pregnancy
2010-08-01ACOG Committee on Obstetric Practice • ACOG Committee Opinion
How is coffee decaffeinated, and is it safe to drink?
2024-08-29C&EN • Chemical & Engineering News
Using Caffeine as a Water Quality Indicator in Ambient Waters
2015-06-01Spence PL, et al. • Environmental Monitoring
Notes on JECFA evaluation (no ADI for caffeine)
2017-01-01EFSA • EFSA FGE 49 summary