SiL is convinced by the kinesiologist who she consulted about her daughter's problems (which seem to be occasional vague tiredness in a pre-teen).
She introduces most subjects with, "Speaking as an engineer/scientist/mathematician..." (she's a chemical engineer) but seems to have suspended all her scientific and/or critical faculties when it comes to this.
Her account of the session, summarised, comes to:
Daughter had to hold her arms out.
Practitioner pushed on her arms and said right one was weak (ie resisted less).
Then wondered, out loud, in SiL's and daughter's earshot, if it was selenium deficiency.
Gave daughter selenium and told her that should help.
Pushed on outstretched arms 10 minutes later. Said that her right arm was now stronger.
Repeat for various other supplements.
Sold supplements to SiL for healthy* amount of money.
Not a double blind trial so maybe not quite gold standard. Placebo effect/willingness of a child to please/ charlatanism...
No. Couldn't be. SiL knows this.
(She also knows a great deal about medicine that actual doctors in the family don't know.)
I realise that's only one experience.
Funnily enough, I haven't a personal experience of my own.
I do have a nice bag that cost the same as all the supplements SiL bought.
And could have still had a slightly less nice bag had I gone to Boots and purchased the supplements from them instead.
*IMO, the only part of the session that did pertain to health.