I am a conservative late adopter. By conservative, I mean "marked by moderation or caution" as opposed to the other political and change-related meanings of the word. I don't start in on the use of any particular healthy life extension technique or technology unless there is a real weight of science to support it.
Science is a debate aimed at discovering the truth, supported by tested methodologies for determining, reviewing, interpreting and predicting facts. Important questions, especially those related to medicine and statistics, are not answered with a single study. Each study, and the resulting debate, can take years. Building - or changing - even a preliminary scientific consensus on any position is a process that spans decades.
People are hungry for definitive answers. Nobody likes an unanswered or partially answered question, but unanswered questions are the essence of science. All "answers" provided by science are theories, possibly wrong in as-yet undetermined ways, and subject to replacement when a better theory emerges.
The human hunger for answers translates to a willingness to accept bad answers - and to pay for answers - if that means getting the answer now. This is especially true when the questions relate to methods to slow or prevent the symptoms and conditions of aging. This facet of human nature allows dubious "anti-aging" products to do well in the marketplace on the basis of limited, poor or outright fraudulent science. Human growth hormone (HGH) is a good example of this beast in the wild. You won't find - or be able to identify - a straight answer on the science of HGH if you go searching online. The merchants, and people who don't sell but are looking for a definitive answer today, have crowded them out.
For me, HGH just doesn't pass the weight of science test. There are good studies, bad studies, and a lot of anecdotal reports and opinions on both sides. This is characteristic of an area in science where more study is needed. It could turn out that HGH is good for some people but very bad for others. It could turn out to extend life span for everyone, but different doses or delivery methods are required depending on your genes. It could turn out that it raises the risk of serious disease. All the indications are that we should hold off and wait for researchers to better understand human biochemistry and hormones. Until then, using HGH is somewhat akin to pulling a big red lever on the side of a complex machine with no operating instructions attached. Quackwatch has some information regarding the history of HGH.
What does pass the weight of science test for me? Calorie restriction, exercise, modest supplementation, a good relationship with a responsible physician, and very little else that is available for use right now. Scientists are, however, on the verge of producing new medicines and technologies that will have great impact on the healthy human life span. The next few decades will see great strides in regenerative medicine, and the first steps towards nanomedicine. With the right levels of funding, and freedom from restrictive legislation, healthy life extension medicine could become an undisputed reality.
This means that activism and advocacy - working to support medical reseach and better medicine - will have a far greater positive effect on your own health and life span than giving in to the desire for (bad) answers to the problem of aging now.