my dad is a cancer survivor for more than 18 y,

he reads up a lot on all sorts of health matters, sticking to solid studies etc

a couple of years ago he pointed out studies to me which say in a nut shell, that re Ginkgo all is nice and well, but brainfunction depends also very much on blood circulation

so that means that it is very important that you do some kind of excercise like walking (uphill)

in order to bring enough oxygen to your brain

----

an auntie of mine was all into homeopathie

brandishing some kind of drops for every occasion, she ate those "magic herbs" in a wide variety and amazing quantities

my impression: as along as you eat a good, balanced with loads of veggies, occasional fish, walnut etc,

you don`t really need it

another fun factoid (delivered by dad)

(especially for older folks) to keep your brain excersised it is important to interact with lots of different persons, that really keeps your brain cells on their toes...

-learn a new language

-stick to some "hobby"/activity and get really good at it

Have you posted your question in the HERBALISM Forum? It might get more responses than this forum, which is meant for the growing of culinary herbs in the garden or containers.

vinca minor, a little enchanting flower, might be good for cognitive functions and concentration ^^ more oxygen flows to the brains, it also lowers bloodpressure and is good for headache

I ordered from the Monterey Bay Spice Company before (which has the ones you mentioned, although they're not what I ordered), and I really liked the experience. Here's a link to their herbs: https://www.herbco.com/c-2-bulk-herbs-spices.aspx

You might also look into Mountain Rose Herbs, but I've never shopped there. If Nuts.com has anything you're looking for, it's a good vendor (but its focus is food).

Ginkgo bilopa is thought to increase blood circulation to the brain, and to have probably mild antihistimine properties. I've taken it on numerous occasions without side-effects, although it might thin blood and interact with blood thinners (not sure). It seems to have a mild positive effect on my cognitive function (but nothing huge). You might grow a Ginkgo bilopa tree. They're pretty cool, and they have lots of leaves. I don't remember much of anything about ashwagandha.