Anywhere that sells both advice and supplements is suspicious. True advocacy and medical organizations rarely sell their own supplements. If it’s a legit place it will sell you advice and let you buy your own meds elsewhere. Even the optometrist and the veterinarian will give you a paper prescription to buy elsewhere.

I recommend finding a neurologist who deals in ADHD. They are shockingly common and way easier to deal with than psychology and psychiatric practices, in my experience. Neurologists treat it as the neurological difference that you can medicate and cope with, not a mental illness or inadequacy. Such a refreshing experience!