Most of the studies of Saw Palmetto have been in relation to benign prostatic hyperplasia in men. The majority of those studies found 320 mg. of extract per day, standardized to at least 85-95% fatty acids with a guaranteed minimum of 0.2-0.4% sterols was both safe and effective. There has been talk of further studies utilising 640mg to treat men with more advanced BPH who did not respond to the lower dose. As there were no significant side effects noted from the studies using 320 mg a day, there is no concern about any potential toxicity from this dose.
Until further studies are done specifically targeting women with androgenetic alopecia I think the best idea is to start with a single dose of 320 mg of Saw Palmetto extract (not whole fruit – it’s important to check for this), which has been standardised as above. If the extract you use is standardised to 40-50% fatty acids as some are, then you will need to take twice as much to get the same amount of the active constituents. It is best to take a single daily dose of saw palmetto first thing in the morning on an empty stomach.
Green Tea & the amino acid l-lysine have both been found to inhibit 5-alpha reductase, the enzyme which converts testosterone into dihydrotestosterone which is the form which causes all the problems with hair loss (and unwanted hair growth). A clinical study with rodents with hair loss found that a third of those studied had significant hair regrowth when green tea extract was added to their drinking water. (Esfandiari A, Kelley P. The effects of tea polyphenolic compounds on hair loss among rodents. J Natl Med Assoc 2005 Jun;97(6):816-8.)
Don’t forget that everyone is different and the amount that will be effective for you may be higher or lower than that which would work for someone else. Herbs have potent physiological actions in the body, just as synthetic drugs do and it is always best to have the guidance of a qualified medical herbalist or naturopathic physician if you are taking herbs.