How Much Caffeine Is Considered Safe?

According to the European Food Safety Authority (EFSA) and the U.S. Food and Drug Administration (FDA), the following caffeine intake levels are considered safe:
Symptoms of Too Much Caffeine
Clinical studies have identified these common symptoms of caffeine overdose (Kerrigan & Lindsey, 2005)[3]:
- Rapid heartbeat (tachycardia)
- Anxiety and restlessness
- Insomnia
- Headaches
- Dizziness
- Dehydration
- Nausea
- Muscle tremors
In severe cases, caffeine overdose can lead to more serious symptoms such as:
- Irregular heartbeat (arrhythmia)
- Seizures
- Hallucinations
- Difficulty breathing
- Loss of consciousness
Understanding Dangerous Levels of Caffeine
Research indicates the following thresholds for caffeine toxicity:
Caffeine Tolerance vs. Toxicity
Research has identified several key factors that influence caffeine metabolism and effects (Nehlig, 2018)[4]:
- Body weight and metabolism (CYP1A2 enzyme activity)
- Regular caffeine consumption (tolerance development)
- Age and health conditions
- Medications and supplements (drug interactions)
- Genetic factors (CYP1A2 gene polymorphisms)
How to Stay Within Safe Limits
Based on clinical research (Temple et al., 2017)[2], these practices can help maintain safe caffeine consumption:
- Track your daily intake
- Space out consumption throughout the day
- Stay hydrated
- Be mindful of hidden caffeine sources
- Listen to your body's signals
When to Seek Medical Help
According to clinical guidelines (Kerrigan & Lindsey, 2005)[3], seek immediate medical attention if you experience:
- Severe chest pain
- Difficulty breathing
- Seizures
- Severe confusion
- Vomiting that won't stop