I came across this web site that says soy and saw palmetto can interact with finasteride. I am wondering if they can potentially exacerbate side effects, as I experienced side effects b/c of Propecia and I was on both of those (and still am on soy).
Also, I’ve heard quercetin, which is found in citrus fruits, broccoli, green tea, red onions, red grapes, etc. utilizes the same enzyme that metabolizes Propecia, thereby increasing serum levels of the drug and leading to potentially more side effects. I also started green tea when I started Propecia. What do you make of this?
Much of what you are talking about reflects unsubstantiated claims. There have been mentions about soy isoflavones interfering with some medications, but I don’t believe that the connections you referenced are one to one with regard to the side effects. The mechanism of action of saw palmetto is not clearly defined but there is probably an impact on reducing some of the effects of DHT according to at least one reference I read. You can experiment on your own by stopping the soy and seeing if there is any difference (I am assuming that you are experiencing side effects).
Your logic may be flawed with regard to quercetin competing with 5AR. The human body knows how to regulate the byproducts of metabolism and can increase the amount of 5AR if it’s feedback suggested a shortage of it. I am afraid that you are oversimplifying the biochemistry here.