1. has your husband eaten fava beans with no problems? some people have serious side affects.
2. just curious, from your reading this board, how many people do you think nationwide are taking fava tincture besides aunt bean?
if i were you, i'd try sinemet first, won't kill your husband and you'll know quickly if he responds to l-dopa. why spend weeks/months playing around with mucana or fava if it turns out he doesn't respond to l-dopa, the main active ingredient in both? you'll likely know in a few days. if he responds well, then pursue the alternatives if that's what you want to do. a few days on a low dose of sinemet and stopping won't be addicting or imho harmful but check with your doctor.

my impression is most people use mucana as an adjunct to sinemet. i can't remember any long time poster here using only mucana.