How to Use “However”

When “however” is an adverb, it’s a plain old adverb:

However you do it, do your work with good tools.

But “however” is frequently used as an aside, a pause in the flow of thought. When you use “however” this way, always follow it with a comma.

However, using good tools does not guarantee good work.

What do you do when “however” is inside a sentence? Preceed the word with a semicolon, not another comma! This sentence is wrong:

No modern clinical researcher has returned to Kast’s ideas, however, anecdotal cases have begun to emerge highlighting some people self-medicating with LSD microdoses to treat chronic pain.

https://newatlas.com/science/trial-lsd-microdoses-acute-pain-study-results

We have a judgement call here because what’s before and what’s after the “however” are different enough that the second part of the sentence could stand alone as its own sentence. The passage should be either of these:

• No modern clinical researcher has returned to Kast’s ideas; however, anecdotal cases have begun to emerge highlighting some people self-medicating with LSD microdoses to treat chronic pain.
• No modern clinical researcher has returned to Kast’s ideas. However, anecdotal cases have begun to emerge highlighting some people self-medicating with LSD microdoses to treat chronic pain.

But don’t put a comma ahead of “however”!

Um, a picture. Here’s what came with the article. Can you interpret it? I think it presumes more knowledge of LSD than I have: