Every new class of rejuvenation therapy, and there will be many of them in the decades ahead, will follow a cycle consisting of a few years of rapidly growing hype, followed by a sharp crash of disappointment, and then, ultimately, long years of slow and steady success. People attach great hopes to the early stages of every new technology, unrealistic expectations for sweeping, immediate change and benefit. Those expectations are usually possible to realize in the long term, but they can only be met in the later stages of development, perhaps several decades after the advent of the new approach to rejuvenation. Producing a mature product that meets the early visions needs the participation of an entire industry, much of which typically does not exist at the start of the process.

Every new technology goes through this cycle, lasting decades from start to finish. The life span of a technology is perhaps fifty years, depending on where one wants to draw the line between a given technology and its next generation, and the first decade can be quite the wild ride when it comes to raised expectations and sudden disillusionment. Human beings are just built this way, the incentives operating at every step of the development process produce this outcome regardless of the fact that we've all seen it before.

Nothing happens quickly, even when the course of action is obvious, even when proof of principle exists for a new medical technology. This is the result of the way in which investment and commercial development works in practice, as it is based on a great deal of happenstance in the percolation of new information through communities, as well as the process of finding, organizing, and persuading groups of people. It takes a few years for a potential entrepreneur to move from exposure to concept to launching a startup company. It takes a few years for a company to succeed or fail. It takes a few years for those lessons to percolate through the research and development communities. Similar cycles play out in the grant writing and publish or perish world of research. Several of these cycles may be needed for any new technology to launch in a useful form. This is why even comparatively straightforward advances can take a decade to make their way out of the labs. Nothing is really all that simple in practice, and regulation slows down these cycles of progress in medicine in comparison to other industries.

Why do the early years of development, those leading in to the first clinical therapies for a new medical technology, inevitably involve an excess of hype? Well, firstly it is sufficiently challenging to raise funds for research in the early stages that advocates tend to sell the vision of the complete industry, the end product rather than the first versions. Further, in the world of biotech startups and venture capital, near all investors are looking for the seeds of enormous, industry-changing companies, the big wins that will provide enormous returns on investment. All venture funds provide their investors with returns that are largely derived a couple of big wins amidst the failures and the mere successes, and the financial model for such funds is predicated on finding those few big wins. This cultivates, directly and indirectly, a culture of public relations and industry commentary that is prone to hype, to emphasizing the facts in ways that are attractive to investors. Lastly, the people who would benefit from rejuvenation therapies, or indeed any radical new advance the capabilities of medical science, rarely have a good understanding of the realities of and the underlying science, and can muster an enormous degree of hope on that basis.

It is worth considering that the development of therapies is in fact a difficult and challenging process in its details. It involves a great deal of discovery as matters move from cells to mice to human trials. The early stem cell therapies of fifteen to twenty years ago were an example of the type, in that the simple transplantation of stem cells did not led to the reliable regenerative therapies that were hoped for at the outset, cures that would reverse heart disease and numerous other age-related conditions. These hope led to the establishment of countless clinics and a sizable medical tourism industry. Obstacles were discovered, in the form of the sizable logistical costs, the difficulties in standardizing cells for therapy, the unreliably benefits when it comes to regeneration. Transplanted stem cells do not survive for long, and it is their temporary signaling that produces benefits, changing for a time the behavior of native cells and tissues. After the initial years of work, the results consist of a few standardized approaches that fairly reliably reduce chronic inflammation for a time, a considerably benefit, but that fail to reliably improve tissue function and structure. This is a lesser outcome by far than the goals aimed at by the early advocates and developers.

The development catches up to the early hype, however. It just takes time. Presently the field of stem cell research and development is well on the way towards approaches that are in principle capable of reliably producing regeneration. Some of those are quite similar to the early visions, the transplantation of cells that survive in large numbers to integrate with tissues and improve their function. They result from incremental, steady advances in capabilities, rather than any profound new approach to the problem. Others are indeed entirely novel lines of work that didn't exist, even in concept, at the turn of the century, such as the use of full or partial reprogramming to produce patient-specific or universal cell lines, or even to alter cells in vivo.

The world turns, and we live in an age of change, a revolution in progress in the capabilities of biotechnology and its application to medicine. It just doesn't happen quite as rapidly as everyone would like it to.