Not typically. Nihilism suggests self improvement is meaningless and without value.
Much more I could be considered an existentialist. Both kind of present the truth that life is meaningless and ideas of "good" and evil" are based on human constructs, but they go in different directions after that where nihilists tend to reject all meaning and purpose as impossible to define in any purposeful way, and existentialists believe the individual can create meaning through personal choices and free will that hold value for the individual, which in no way implies those existential definitions hold meaning outside the self.
For example, as much as I find ideas like hope to be outrageous, and accept the horror of the species, I have dedicated my life's work to helping disadvantaged communities, participate in volunteer Fire Department and Police Department, help blind people cross the street, and a variety of other behaviors many might find to be socially valuable.
I do not do these things for praise, I am uninterested and often uncomfortable with recognition for them, I do them because I believe it is the right way to behave, I have a moral standard for myself, and I am strict with it.
I however do not think this behavior makes me better than anyone else, nor am I frustrated that most others do not share my interest or commitment to these behaviors. I do these things because I must, because it is my choice. The opinion of society at large is irrelevant to it.
A Nihilist is unable to keep such conviction and a commitment to honor is antithetical to their philosophy.