Gingko sharpens memory and has been used for thousands of years!
Vitamin B6 is a communication lifesaver for the body. It contains the building blocks that allow our body to be structured and intake information.
Rosemary oil has been shown in recent studies to be instrumental in improving memory function.
Let the roots take you back to before you had tendonitis. Ginger and turmeric are both anti-inflammatory. The effects won't kick in until after about 2 months of taking it so start it as a preventative measure. This can help the overall well-being as well.
Mate helps the late nights, long practice days, little sleep, carrying lots of equipment. Coffee might help as a go-to pick-me-up but after an hour it will drop you like it's hot. Yerba mate is a "keep-me-up" according to www.makingmusicmag.com
Seems too simple, right? There are calming herbs out there that would put you to sleep if you overdo them (valerian root, chamomile, passionflower). If you have a gig and want to be pumped/relaxed, green tea is perfect for that. It has the caffeine for a boost and theanine for relaxation.
Gotu Kola may be more abstract to people, but it has a 5,000 year history from India. It has been shown to promote relaxation while also improving brain function.