In case anyone is curious about L-Theanine, it's very often used by people with interest in Nootropics for focus along side caffeine. The Theanine-Caffeine stack is considered to be the sort of entry or gateway into nootropic territory.
With typical dosing being 100mg caffeine:200 mg l-theanine
You can buy l-theanine pills and take it with coffee. If you'd like it from nature, Matcha has the highest L-theanine content. This is because L-theanine is an anti-oxidant made in the roots and sent to the leaves to prevent against damage from the sun. Matcha tea plants are kept in the shade for the last couple of months, so they build up the theanine and it is not used up. The full leaves are then ground up, but will only contain around 40 mg per serving, which is why I generally recommend supplementing it. Suntheanine has a patented form that is made in a biofermentation process that yields nearly 100% pure L-isomer theanine.
Also interesting is that, while L-theanine the molecule wasn't "discovered" until 1949, the Japanese ceremonial tea scale has been for hundreds of years, organized by increasing levels of theanine content.
I've tried other caffeine products and l-theanine alone, nothing had that great effect as Xenadrine did, I'm not sure if maybe one of the other ingredients is a nootropic either, could be, I imagine, or could just be the quantities.
Coffee and normal caffeine doesn't do much for attention/focus for me... but I drink way too much soda..or did.. (weaning off)... About to do keto for a few months.
Although the research in this area is very inconclusive afaik, it could even be placebo.
I was aware of this already—thanks for bringing it up though, since I think it’s important that people be aware of it. Unfortunately I haven’t found an equally effective yet safer replacement for nausea & allergies. Ginger works pretty well, but iirc that’s because it’s also a mild anticholinergic/antihistamine.
I would recommend avoiding anticholinergics!