Totally subjective, completely non-rigorous. That said: - I'm middle aged and have had tens of thousands of cups of coffee - The difference is pronounced, no

Totally subjective, completely non-rigorous. That said: - I'm middle aged and have had tens of thousands of cups of coffee - The difference is pronounced, not subtle - It's well-studied https://pubmed.ncbi.nlm.nih.gov/18296328/ https://pubmed.ncbi.nlm.nih.gov/18296328/ FWIW, I've played around with a lot of supplements. Generally the effects are non-existent or subtle. I'm not generally given to a placebo effect wrt this kind of stuff