Simon, you are passing on very poor information here.
From someone that spent almost my entire working life in the pharmaceutical world, I can tell you from personal experience that everything you get from that industry has been tested, checked, counter checked, and checked again before it is allowed out into the market place. Nothing they sell can be released to market unless it is approved by a qualified and very experienced individual who is legally responsible for the safety and efficacy of the product they have released. Everything they use as a manufacturing substrate is supplied from a known and trusted source, and is legally listed in the production license application. All operations carried out during manufacture are logged, and all production parameter data is recorded and kept for ten years past the shelf life of the product. Every anomaly that occurs during manufacture, no matter how trivial it may seem, is investigated and the potential impact on product safety assessed and recorded. Key ingredients must come from a regulatory approved source, and cannot be substituted with an alternative (even from another approved source) unless the alternative has been tested to the same rigorous standards and the change is agreed up front by the industry regulators.
In comparison, alternative therapies and diets use ideas and suppositions that are passed on by word of mouth, use untested ingredients, sometimes from extremely dubious sources, and have no basis in scientific methodology. They may be dressed up as pseudoscience for marketing purposes, and to “sell” the latest antivaxer diatribe, but they do not undergo peer review and are not subject to regulatory review. Personally I would not subject myself to such a regime unless I had checked with my GP that it would do no harm. I certainly wouldn’t expect it to do much good, unless it was more by luck than judgement.