Across 2,414 first-hand reports, people mentioned a side effect 577 times (about 24 per 100 reports). The most common: jitteriness, anxiety, insomnia. User reports show what people notice — they can't tell you whether Caffeine is safe for you.
“I have a love hate relationship with caffeine...if I drink any past 10am it can effect my sleep.”
“I no longer have any anxiety or existential or suicidal thoughts, and I am much happier and outgoing and social.”
“I've already noticed my face just looks better. Wrinkles aren't as pronounced and my face isn't as dried out looking.”
“it would give me crazy anxiety and dizzy spells. Especially when standing up.”
“If I drink caffenated after 10am I will not be able to sleep all night. So I just took the Novos quiz which flags which healthy habits you should improve and they said I need to drink more caffenated coffee.”
“Too much caffeine would make me feel weird and irritable. A soft drink was just right.”
Conclusion: The authors recommend that individuals avoid frequent energy drink consumption (5-7 energy drinks/week) and avoid co-consumption with alcohol; increased regulatory standards should be placed in the sale of energy drinks, particularly with regard to the pediatric population.