Lets say a new treatment had been devised that would increase your lifespan by a minimum of 1000% (you would live at least ten times longer). You would be immune to all disease and have perfect health for all of your life. The treatment is free and offered to everyone who wants it. With your longevity, you would help to create and live in a utopian society where all luxuries and necessities are provided free to all people, and scientific/technological progress is considered paramount. You would be able to pursue any lifestyle you choose.
However, the treatment has side effects - you would become hairless, shrink to 4 feet tall and become physically frail, your skin turns a sickly grey, your eyes become bulbous and black. You may find being outside unpleasant. But nobody will care about your appearance, you would not be considered ugly by other people or even yourself, and many others are also taking the treatment as well.
All of these effects, both positive and negative will be passed down to your children and all of your descendants. With enough time, the original human race may end up being completely replaced.
This is a hypothetical future world. The new breed of humans will advance their scientific and technological progress, and become much more intelligent. They will have the means to colonize other planets.
The side effects are irreversible. They are inexorably linked to the benefits, and it is utterly impossible to either separate them or to 'cure' them without loosing the increased health and lifespan.
Will you take the treatment?