Here is some colourful language for you: Dominic Cummings makes my memetic immune system want to vomit.
Part of it is because he sets off my Malcolm-Gladwell-o-Meter, but mostly it’s because he’s trying so hard to appear more knowledgeable and well-educated than he actually is. He surrounds himself with the trappings of expertise he obviously doesn’t have. Case in point: this “paper” is clearly a blog post which he converted to PDF via MS Word because he thinks that makes it look more credible.
The effect for me is a bit like receiving an email from a Nigerian prince, asking for your help in getting millions of dollars out of the country. My response is approximately the same.
Phase I clinical trials exist for this purpose. The objective of Phase I trials is to establish safety, dosage, and side-effects of drugs in human subjects, and to observe their proposed mechanism of action if relevant.
It’s rare for Phase II and III trials (which have clinically-relevant endpoints ) to be carried out on healthy subjects. Part of this is ethical considerations, but also clinical trials are extremely expensive to carry out, and there’s not much payoff in learning whether your drug has some specific effect on healthy subjects.