Hi Susan's,

I received some information from about MtF HRT from a reputable clinic in a major US city. In the information was a cautionary statement that one ought not to take more than the prescribed dose of estrogen, because excess estrogen gets converted to testosterone.

I believe this statement to be false. My understanding is that the enzyme aromatase converts T to E, but there is no natural metabolic pathway to convert E back to T.  I know Wikipedia is not absolutely authoritative: http://en.wikipedia.org/wiki/Aromatase Can someone suggest a source more authoritative than Wikipedia?

Or am I the one who is mistaken here?

Please understand I am *NOT* advocating anything other than taking the dose prescribed by your doctor.  It's just that you shouldn't give a WRONG reason (a scare tactic) to do the RIGHT thing (to follow your doctor's instructions).

I'm just sayin....

The mechanism of aromatase converting testosterone to estrogen is a one-way street.
Their is no mechanism for converting estrogen to testosterone.

I have heard reports of people being given these stories presumably to dissuade them from abusing estrogen.

What Renate says is true.  However, if you are not on androgen blockers and start to put oestrogen into your system your body may respond by producing more testosterone.  The higher the E possibly more response to produce T.  Some clinics and some professional are in a habit of reporting information in an inaccurate way to 'receive' your  attention.  As long as you are with professional endos and medics just follow what they say. (IMO)

Cindy

If a distinct increase  in  serum  estradiol is  sustained for approximately 36 hours (1), a positive feedback becomes manifest, this promote the excretion of GnRH results in LH surge that causes testosterone production to increase temporary, after that the level drop back to normal. When steady level of serum estradial is maintained, and if the level is sufficient to manifest as negative feedback, then the secretion of GnRH will be suppressed (2) , result in lower LH level which reduce testosterone production.

Reference:
1. NEURAL  CONTROL  OF  OVULATION*Judith  L.  Turgeon.
2. http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/SexHormones.html

It ain't so.

Hi everyone,

Thanks for your comments. I did raise this issue.  A medical professional I spoke to confirmed it was an "oversimplified statement" of the situation described by Cindy and Joyce.  But they did also insist that E -> T conversion can indeed take place, albeit on a small scale on an intracellular level. I'm not trying to make a federal case out of it or anything. It's just that there's so much BS out there, it's important to be right about all the details.

QuoteA medical professional I spoke to confirmed it was an "oversimplified statement" of the situation described by Cindy and Joyce.

Why don't you ask him what is the enzyme responsible for E -> T conversion, instead of having to search for answer yourself? To me, as long as there is no such enzyme, E -> T conversion is not going to happen.