Caffeine Side Effects and Safe Daily Limits

Caffeine is well tolerated by most adults and genuinely unsuitable for a meaningful minority, and knowing which group you are in matters.

The general limit

Regulatory bodies including the EFSA and FDA regard up to 400mg daily as not raising safety concerns for most healthy adults, with 200mg as a single dose. For reference, a filter coffee is roughly 95mg, an espresso 65mg, and an energy drink 80 to 150mg. Supplement doses vary widely and should be counted.

Common side effects

Jitteriness, racing heart, anxiety, digestive upset, headache and — the most consistently underrated — disrupted sleep. With a half-life of five to six hours, a 2pm dose leaves a meaningful fraction circulating at bedtime. Poor sleep then raises next-day appetite, quietly undoing the point of taking it.

Who should be cautious or abstain

Anyone with an arrhythmia, uncontrolled hypertension or a history of panic disorder. Anyone on medication for blood pressure, heart rhythm, thyroid, anxiety or depression without medical clearance. Pregnant women, for whom limits are much lower. Anyone under 18. And slow metabolisers, who feel a single coffee for eight hours.

Practical rules

Count every source including supplements, and treat a product like SodaSlim as one of your servings rather than a free addition. Keep the last dose before early afternoon. Stop and reassess if resting heart rate rises or sleep degrades — those are the signals worth acting on.

Editorial note: This article is general information, not medical advice. SodaSlim contains caffeine and is not suitable for everyone — see who should not take it and our full disclaimer. Individual results vary and no outcome is typical or guaranteed.

Keep reading: what SodaSlim is • how it works • the ingredients • the benefits • our full review