I don't know that lactating is such great idea. (I certainly have no desire to! I might reconsider if I had a baby that required nursing.) But I've heard of an herb that might warrant investigation: Euphorbia lancifolia. You can buy the plant at www. alliesonline.net - for what it's worth - But I'd be careful if I were you. Sometimes the greatest danger lies in our 'success'! And who's to say that this herb is safe? Or what if you have an allergic reaction to it?
Although, I've also gone headstrong into worse foolishness - I'm sure!
Lactation is one of my eventual goals.
From the reasearch I have done on the internet, there seems to be two possible ways of starting lactation.
1) Simulate a pregnancy hormonally... when a genetic woman is pregnant her hormone levels rise, so increasing your hormones for an extended period of time (we're talking the normal length of a pregnancy), then dropping them suddenly (birth), should start the flow. This method takes a lot of time and patience, plus there is a decent chance it won't work. However, if done with the doctor's supervision, it seems to be the most reliable method.
2) Most pages I have read say that if the above method doesn't work, you can manually work your breasts (usually with a hospital quality breast pump) and get lactation started that way. If I remember correctly, they generally recommend you pump for about 15 minutes every 3 hours or so, allowing only a 5 hour block for sleeping. I may be wrong about some of those numbers, but that gives you the general idea as to how intense of a regimine it is.
As you can imagine there is no great comprehensive study on transsexual lactation. From my own perusing of the internet there are several things that I would consider fairly accurate.
a) Since transsexual breasts grown via hormones are the same as a genetic female's, information about starting lactation in females who aren't pregnant should be applicable, too. Perhaps not entirely the same (from comparing it seems as though method 2 above doesn't need to be performed quite as frequently for a genetic female) but similar. So try searching google or ask.com or whatever your search engine of choice is with keywords like "lactating without pregnancy" or "lactation" and "Adoption" (since that is the main purpose genetic women have for inducing lactation without being pregnant.)
b) The mind plays a big role in the process. If you can actually nourish someone... or make believe that you are... it is more likely to happen (or sooner).
--I would even say, though have never really seen it mentioned anywhere, that just the act of selflessly caring for or serving someone else (even if lactation is not needed) while imagining the love flowing through your breast and resulting in milk would definitely not hurt... and I think might even help. However, there is obviously no way to test that or prove it... but it might be an exercise to try.
---Continuing on the mind path, it seems as though positive re-inforcement of not just lactation, but our journey as a whole really helps. If you believe you can do it it will be easier. My general rule of thumb is don't be shy to use the mind. It doesn't cost anything, is simple, and many people swear that it exudes a lot of control over female sexuality.
c) For some transsexual women it just happens naturally. From what I gather it's not common, per se, but also less rare than we might innitially suspect. I know there have been multiple threads in these forums where a TS posts about naturally lactating. Since they didn't do anything to encourage it, I can only imagine how much they might lactate if they did start pumping regularly and all that.
I have found a number of good pages on the subject specifically of transsexual lactation, however, I must have found them using an odd keyword search string because they're not coming up when I plug in the obvious terms. When I just searched before typing out this post I had several in mind that do a good job of explaining the various techniques and what you can expect from them. But didn't find any of them. I did find this post instead, which seems on a brief glance to be very long, thus (maybe?) exhastive. http://etransgender.com/viewtopic.php?t=410 I haven't read any of it (it's too late for that!) but it may provide some helpful information.
Also search the forums here. I know I had posted a good link awhile back on the topic.
Oh, and regarding herbs: While I have read about herbal preparations that might boost milk production, I have yet to read anything about STARTING lactation in anyone, female... male... or inbetween. More likely you need to get the lactation started, THEN possibly consider taking something to help increase your production.
Hope this helps. (If it doesn't its because I'm tired as hell and will be going to bed as soon as I get this computer off!)