A couple of years ago I read a case study in an Australian medical journal in which an elderly (approx 70yo) man with Parkinson's who worked as an arborist in a fruit orchard came to his physician, the author or the paper. He complained of serious fatigue and depression. The doctor administered testosterone on a weekly basis, resulting in apparently great improvement in both conditions within a few weeks.

Otherwise, I have not heard of this approach in a Parkinson's case.

caveat; Slow-growing prostate cancer may be sped up by added testosterone.

Robert