There’s a common rumor that steeping tea leaves for too long releases excessive theophylline, leading to side effects like toxicity or sleeplessness. Is this actually true?
How Long Does It Take for Tea to Release Theophylline?
Tea leaves do contain theophylline, and small amounts are released during brewing. However, the levels are extremely low and pose virtually no risk to human health. Here is what the Taiwan Tea and Beverage Research Station has to say:
The alkaloids in tea leaves are primarily purine alkaloids and a small amount of pyrimidine alkaloids. Purine alkaloids include caffeine (making up about 2–4% of tea leaves), theophylline (making up only about 0.002%), and theobromine. The amount of theophylline in tea leaves is naturally minuscule, so its potential side effects are negligible. Therefore, with normal brewing and drinking habits, there is no need to worry about theophylline levels or side effects.
Does Theophylline in Tea Cause Sleeplessness?
The main culprit behind sleeplessness isn’t theophylline—it’s caffeine. Here is another insight from the Tea and Beverage Research Station:
Since theophylline levels in tea are inherently very low, sleeplessness after drinking tea is actually caused by caffeine remaining in the body due to slow metabolism and elimination.
Conclusion: If you’re worried that over-steeping tea releases too much theophylline or causes toxicity, you can rest easy—the amount of theophylline in tea is extremely tiny. Furthermore, caffeine—not theophylline—is what keeps you awake. If you want to prevent caffeine from disrupting your sleep, check out our article: “Does Drinking Tea Cause Sleeplessness? 3 Simple Tips to Prevent Insomnia.”