Feedback suggestion Stevia for back pain

I received an email from John, via the "Contact me" button above, with an invalid reply email, so posting here instead. John posted:

Chinatown Bangkok they sell plastic bags of unprocessed dried stevia. looks like a bag of ganja.
anyhow just a leaf or two solves any back problems i may get for months.
the processed stuff i can find online may or may not work, but worth a try. not going to do you any harm as its primary use is as a sweetener for teas etc.

My reply, that bounced:

John,
I am growing Stevia Sweet Leaf (Stevia rebaudiana), the plant that is used to make sweetener.

Only put the young plant in a couple of months ago, have already been plucking leaves and using them in salads. Adds a sweet tang to the salad.

Never knew about the back improvement! Good, will keep eating it.

I am not currently having a back problem, as always mindful to keep the posture erect with lumbar region concave, especially when sitting in a chair. However, hiking will introduce stresses that will challenge the back. Will not be using a backpack which is good, but getting in and out of a tent, crawling around in the tent, has always been a challenge. Scrambling over rocks, climbing hills, also puts unfamiliar stresses on the back.

OK, Stevia might improve the back situation, but how? What does it do? I did an online search:

https://thelivingwell.com/stevia-side-effects-is-it-safe/

...oh. The suggestion in that post is to only consume the leaves, not the processed products, however, this link suggests the opposite:

https://www.stylecraze.com/articles/side-effects-of-stevia/

...that link mentions numbness, which would explain John's experience.

Well, I have the plant in the garden, and the leaves are nice in salads, for the taste contrast. Might continue to use it, but restrict to a few leaves each time. 

Tags: ethos