THE EVIDENCE GAP: WHY SOME THINGS ARE TESTED AND OTHERS ARE NOT

Regulators, rightly, require evidence to approve a product for sale. This means there is funding for pharma and medical products

You can patent synthetic products or devices, meaning you can make money exclusively from them. You can’t do this for natural products as they’re not proprietary. This means that any seller would benefit from the funding one seller put in to fund a trial - funding public goods like this does not make commercial sense.

Not everything can be tested using gold standard methods. E.g. ethical issues (you can’t randomly allocate pregnant women to smoke, for example)