MGT explicitly states there are dangers in using anagathics.

As anagathics effect the whole body and the fundamental mechanism of aging, we are talking a pretty serious drug here. The fact that it is a 'choice' to take does not, just as in the real world, remove the generally accepted responsibility of most societies/governments to protect their citizens. Freedom to commit suicide is often restricted - as is voluntary and involuntary manslaughter...TMB pg 36-37 said:Characters can prolong their youth using anagathics (drugs that slow the aging process), but these are hard to find, expensive, and illegal or socially unacceptable in many parts of the Imperium. ...
If a character stops taking anagathics, then he must roll immediately on the aging table to simulate the shock that comes from his system beginning to age again....
Anagathics have two drawbacks. Firstly, the risk of trying to obtain a reliable supply and the disruption to the character’s biochemistry means the character must make a second Survival check if he passes his first Survival check in a term. ...
