Hi OlliePOP.... I just go to my local health food store and / or natural foods market and have them order me organic sproutable fava beans. Usually get at least 20 lbs, but if you are not sure if they will work for you...I'd recommend a 5 lb bag . The tops of the plants are not as strong as making tincture from cut up fresh harvested fava bean outer pods. They are holding my dopamine level for a longer period of time , also require less tincture for a dose. Tops tincture is the only thing that has been tested...have trouble finding a chemist that will volunteer time to do testing. Tops tested out as a tincture L-dopa content of 2 drops equal 1 mg. not much , but very significant for treating my symptoms. I started out in October of 2009 taking 2 drops 3 times a day. Now with that same fava tops tincture, I require 2 droppers full (about 20 drops each) approximately 4 to 5 times a day, depending on stressful situations/ playing music out somewhere/ or just having a normal quiet day at home. Also depends on foods available. Peppers/ egg plant/ green tomatoes/ papaya /and watermelons all help me function better and I require less L-dopa. Also good exercise helps my symptoms (digging in garden/ dancing...and now we have a rescued chocolate Labrador retriever 2 yrs old that weighs 60 pounds that is increasing my activity level (just washing floors morning and night from foot prints and "slobber's" that he leaves everywhere. Like having a baby around...I may be too old for this. But, warm weather will come eventually and he will be outside 24/7 . And, that will be wonderful! A Blessed Christmas to you all from BEAN ACRES.