Imagine an online shop for supplements which are candidates for life extension.
If you order anything from them, they will store medical data (age and why you buy this product).
Some months later you will be aked to give feedback on the product.
Do you feel younge or olderr?
Did you experience changes in your energy leve / endurancel? (worse, unchanged, better...)
Did you experience changes in skin/hair?
Did you experience changes in weight?
Did you experience changes in your immune system?
Did you experience changes in cardiovascular parameters (better blood pressure,...)
...
The results should then be available to the public, ideally with some tools to analyze (like mean values or selection of age groups).
Of course this would not be double blind, nor placebo-controlled. But it would provide a lot of hints about which supplements might work for a certain condition.
With something like this it would be possible to identify candidates automatically, and everyone could be a lab rat. What would you think about this?