Huh. Mihari's de-age-and-gender-bend drug isn't exactly a youth potion, since you have to keep taking it, but it's not not a youth potion either. I suppose junior high would be a little young for a tenured academic to abruptly revert to, but it could be worse.
(Admittedly, the worse I'm comparing to is the "failed immortality drug" of 100 Girlfriends' Yakuzen Kusuri, which de-ages you to 8 and locks you there, though the weaker versions can be temporarily overriden by Kusuri's all-purpose drug negating drug, returning you to your biological age temporarily. I fear the crossover potential.)