What were some of the effects Dr. Jekyll stated were an effect of the "impure" drug in The Strange Case of Dr. Jekyll an Mr. Hyde?

Let us remember that it is in the final chapter of this
story, which features Dr. Jekyll's own account of what happened, that we discover that
the initial power he used was impure, which gave the potion he created its strength and
miraculous powers. The first time that he tried his concoction, he explains the physical
and mental results that ensued:

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The most racking pangs succeeded: a grinding in
the bones, deadly nausea, and a horror of the spirit that cannot be exceeded at the hour
of birth or death. Then these agonies began swiftly to subside, and I came to myself as
if out of a great sickness. There was something strange in my sensations, something
indescribably new and, from its very novelty, incredibly sweet. I felt younger, lighter,
happier in body; within I was conscious of a heady recklessness, a current of disordered
sensual images running like a mill race in my fancy, a solution of the bonds of
obligation, an unknown but not an innocent freedom of the
soul.

Note the way in which,
in spite of the physical pain that Dr. Jekyll experiences, by far the most important
effect of the drug is the new "liberty" that he feels and the way that it gives him "not
an innocent freedom of the soul." Even though the drug has a rejuvenating effect, it is
shown that this is not a positive process, as he is overwhelmed with "sensual images" as
he himself realises that he is "more wicked, tenfold more wicked" than he was in his
previous existence as Dr. Jekyll.