I did one a few years back for a statin in injection form and it is now on the market with great results.

as my favorite dr said many years ago to me never do clinical trials . they are there to see 1 if med works 2 see if there are side effects 3 to see if it can harm or kill people . so on that advice i would say not too . but of course it is everyone's choice not mine

If I had tried everything and the outlook was hospice looming then why not, all to gain and nothing to lose.

Just finished a 6 wk trail for couples dealing with cancer for Duke . NC. Zoomed once a week for a hr. It was the best trail . So informative and a few $$$ for it.

I think they can be very beneficial. One should carefully weigh the pros and cons of a clinical trial because sometimes the risks far outweigh the benefits. Some questions to ask:
Why is this drug/treatment better than existing ones?
How many participants are there in the study?
What condition does this treat?
How many of the participants have this condition?
What are the potential long term risks?

Clinical trials help provide data for proposed treatments. Many of these treatments are in some degree of experimental process and therefore there are still many questionable outcomes. If the benefits outweigh the risks and you think that it's worth pursuing I say go for it as long as you are comfortable accepting the risks.