There are great many people willing to rain fire and brimstone upon the merest mention of clinical studies in which the patient pays the costs. They emerge whenever any group runs such a study, or whenever an initiative earnestly proposes greater adoption of this structure of trial for medical procedures. At root, there is a sizable fraction of the population that seems very hostile to the idea that patients be allowed to choose their own risks, and we see this hostility whenever some loosening or adjustment of regulation is proposed. Petty authoritarianism, yes, but to the degree that it shuts down responsible experimentation and progress in medicine, and slows the pace of development as a consequence, it is just as harmful as the real thing.
A primary complaint about the patient paid structure is that it is impractical to conduct blind studies or use placebo treatments in a control group, as people tend to want to get what they paid for. This greatly reduces the ability of a study to assess the presence or absence of effects that are small, intermittent, or vary widely between patients due to as-yet unknown factors. If you are looking for small and unreliable effects, and sadly this is pretty much the case for most modern medicine for the treatment of age-related disease, then this is a fair criticism. You should not be trying to use this sort of trial structure in such a scenario.
However, when it comes to rejuvenation therapies we are not interested in small and unreliable effects. Small and unreliable is the same as failure. The SENS rejuvenation research programs, and any other initiative to repair the causes of aging, is aiming for large and reliable effects. The expectation is certainly there for success in addressing any of the molecular damage at the root of aging to produce reliably beneficial outcomes in patients. We all age for the same reasons, and a beneficial therapy in one individual should be beneficial in every individual of much the same age group. But people are used to the marginal effectiveness of present day medicine, the quest for tiny, incremental, unreliable gains, and that steers their expectations regarding the appropriate way to proceed.
When it comes to placebo treatments, it is arguably the case that some types of patient paid rejuvenation therapy trial could be structured to include them. Consider senolytic treaments that clear senescent cells, for example. One could envisage a trial that involves two treatments two weeks apart. One is a placebo. After each treatment, metrics are assessed. In mice, beneficial changes following elimination of senescent cells occur quite rapidly, as the senescence-associated secretory phenotype is cleared out. There will be measures of health status in humans that can be checked a few days or a few weeks later. So in general, there are often ways to proceed with a placebo for short-term studies and short-term measures.
Yes, for longer-term patient paid studies the use of a placebo control group just isn't practical. Again, however, the point of the exercise is the detection or confirmation of reliable, large effects. It is perfectly viable to use the rest of the population as your control group. If a senolytic therapy cuts back all sorts of measures of metabolic age quite quickly, to a degree that can only be achieved via other methods over a long period of time, if at all, then it is hard to reject that out of hand just because there was no control group of study participants. Based on the results in mice to date, and what is known of cellular senescence in humans, one would expect the first drug or other therapy to replicate the same degree of cell clearance in humans to be so very evidently beneficial that attempts to run blind studies with control group will be pointless - they will add little.
The response from the more conservative end of the scientific community following a patient paid study that shows significant benefits should be to pull in funds and interest to run their own more structured and careful studies to better quantify and improve upon the results. Publicity from the patient paid study will help them to do that, breaking through the reluctance that seems to characterize much of the industry. The patient paid structure is a way to bring in the necessary funding to carry out pilot studies in the absence of funding bodies within the existing institutions willing to do that. Given the history of the development of senescent cell clearance as a field of medicine - the long years in which it was ignored despite the compelling evidence, the struggle to fund the landmark studies in mice that proved that removing senescent cells could reverse aging - we should all be very skeptical that existing institutions will ever fund worthy projects in rejuvenation research if left to their own devices. They need to be kicked into action by outside efforts and outside funding, as they are otherwise happy to drift along performing marginal work.
If we want radical change to take place in the research community, if we want to see more work on human rejuvenation based on the SENS vision of repair therapies that can turn back aging, then patient paid studies are an important tool in the toolkit. Money doesn't grow on trees, and there are costs involved in getting the job done. Patient paid studies are one of the ways to overcome that hurdle.