Can you develop a tolerance to l-theanine? I've heard both you can and can't. For example I've taken 200mg with my coffee every day for probably the past 2 years. I take it because it helps with focus and helps my anxiety.

But I've heard that with long-term use, it won't work as well and anxiety will get worse. But I've also heard it's fine and you can't develop a tolerance. What's the truth?