Yes. 20mg/day. I don't see any clear reduction of symptoms (e.g. tremors, insomnia, orthostatic hypertension), but I really felt like the best case scenario would be that it would stop progression, which would take a long time to see. I don't think I'm seeing any side effects though.

I attended the Grand Challenges VAI event in Michigan this week, and asked a panel of PD researchers what they thought of the doxy approach. They were dismissive of it.