From Erowid.com.
Caffeine
What are the short term effects of caffeine on the body?
Caffeine increases heartbeat, respiration, basal metabolic rate, gastroenteric reflexes, and the production of stomach acid and urine; and it relaxes smooth muscles, notably the bronchial muscle. All of these changes vary considerably among people and may depend upon the individual's sensitivity to this drug, his/her metabolism, or upon whether the consumer habitually uses or rarely uses caffeine. How long caffeine's effects last is influenced by the person's hormonal status, whether he/she smokes or takes medications, or has a disease that impairs liver functioning.
Subjectively, people report that caffeine gives them a "lift." They feel less drowsy, less fatigued, more capable of rapid and sustained intellectual effort. They also report improved performance of some manual tasks such as driving. However, caffeine may restore only those abilities or feelings the person had before fatigue or boredom set in. Studies have also shown that caffeine decreases reaction time to both visual and auditory stimuli; it does not significantly alter numerical reasoning (arithmetic skills) or short-term memory; and it can diminish performance of manual tasks that involve delicate muscular coordination and accurate timing.
When caffeine is taken in high doses it can cause many unwanted side effects. To learn more about these, please read "What are the symptoms of caffeine overdose?"
Withdrawal Symptoms
Caffeine has the potential to produce tolerance, which means that increased amounts of the drug are needed to achieve a consistent effect. Withdrawal symptoms can occur when use of caffeine is stopped abruptly. Users may experience fatigue, and most commonly, headaches. Primary withdrawal effects last for only a few days though mild withdrawal effects can last as long as a week or two.
* craving
* tiredness, lethargy
* confusion and inability to focus
* headaches, which may not respond to painkillers, but may abate with the intake of caffeine
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the site is very informative and has a lot of warning fact sheets.wonder why it is banned.
Guess it's because they never blatantly say they discourage drug use, but banning it just because they do not follow Singapore laws is not the way to go.
