[thebigspacefuck]

I believe the 1.5 hour half life is only for smokers

Edit: the mechanism seems to be due to inducing Cytochrome P450 1A2, an enzyme responsible for caffeine metabolism and many other drugs. This is also induced by diet with cruciferous vegetables and medications like Prilosec/Omeprazole. So if you find yourself sleeping better or needing more caffeine to get through the day, ingestion of these could potentially explain it. Likewise it can be inhibited by foods such as cumin or turmeric and medications, so if you notice more energy after turmeric supplementation or heightened caffeine sensitivity after eating more Indian food or your sleep is impacted when you start taking oral contraceptives, this could potentially explain why.

See inducers and inhibitors here https://en.wikipedia.org/wiki/CYP1A2