https://www.reddit.com/r/adhdwomen/comments/17zu4zj/ltheanine_has_saved_my_life/ These Redditors discuss their supplement experiences. Try green tea!

https://www.nccih.nih.gov/health/providers/digest/adhd-and-complementary-health-approaches-science Here's a comprehensive review of the research for a wide variety of supplements. Most of the research is inconclusive because there haven't been enough studies done. However, the studies that have been done have shown that supplements don't measure up to stimulant medications like methylphenidate (Ritalin).