The effects of testosterone on female bodies

[Melamin]

twitter.com/MLaidlawMD/status/1005790356988784641

This was an interesting thread on twitter - the levels of testosterone in female bodies.

From what I understand, from my rusty biology, the effects of oestrogen on the body are not too damaging and also offer some protection from heart disease. However, the effects of testosterone are more damaging and there does not seem to be much research into giving female bodies large amounts.

I know that, in HRT land, small doses of testosterone can be prescribed off-label to women under advice from a consultant. This can help with libido, especially when ovaries have been removed. These are very tiny amounts though.

Does anyone know of any research on the effects of giving large doses of testosterone to women?

I'm interested too.

Slight tangent: I will point out a phenomenon I've noticed: Transman's voice.
When testosterone alters a woman's voice, it drops to a lower range, yes, but it (to me) takes on a quality that is quite recognisable and different from men's voices. The best I can describe it as is a type of 'vocal fry'.
I don't know if it's an unavoidable result of the testosterone on female vocal chords or a conscious attempt to force the voice into a lower register which isn't working well.

But I've noticed it in several transmen who visually are 'passing' quite well, yet vocally have this 'tell'.

Has anyone else noticed this?

Is that like DS trying different parts of his voice when it first broke, until it settled and he forgot about it? Or is the development of the larynx getting stuck at an earlier stage, like the tanner stage 4 breast development in MtF?

I was wondering, having read these tweets, what research had actually been done. I know that testosterone replacement for hrt is very conservative and tentative due to limited research on the doses and women usually use about 1/5 th of the lowest available male dose as that is all that is available.

Also, as there is a huge rise in young FtM, it is important.

Taking testosterone is linked to an increased risk of heart disease, diabetes and cancer and an increase in mental illness.

Most research is found under sport-doping and steroid/testosterone use.

I will point out a phenomenon I've noticed: Transman's voice
When testosterone alters a woman's voice, it drops to a lower range, yes, but it (to me) takes on a quality that is quite recognisable and different from men's voices

Yeah, like a bit "scratchy" or something. I've noticed this too.

I absolutely agree that testosterone use (for life!) is a massive risk, and I haven't been able to find any long term research on what happens - the East German athletes are probably the closest, although their treatment probably was an out and out abuse with no care for their future.

This is the evidence that the NHS bases it's treatment on (and note there is no reference to any evidence about testosterone use in natal females), note also use of words like "appear" "seem" "might":

"Cross-sex hormone therapy appear to be safe, with mortality rates of those undergoing treatment the same as that of the general population. Hormone dependent tumours might be a cause of the use of cross-sex hormones but findings need to be supported by further research. A 2012 study by Asscheman et al6 reported a three-fold increase in risk from cardiovascular death with current (but not previous) use of ethinyl oestradiol. The authors concluded that increased mortality in hormone-treated trans women was mainly due to nonhormone-related causes and that the use of testosterone in trans men at doses used for the treatment of male hypogonadism seemed safe. Also in 2012, Seal7 et al reported that treatment with conjugated equine oestrogen was associated with a higher incidence of thromboembolism than treatment with other oestrogen types, and that self- medication, particularly with spironolactone, was associated with increased subsequent requests for augmentation mammoplasty. Overall, there is only limited evidence to demonstrate the efficacy of hormonal therapy or gender reassignment surgery with regard to long-term complications or physical functional status"

This is the document here:
www.engage.england.nhs.uk/consultation/specialised-services-consultation/user_uploads/gendr-ident-policy.pdf

The endocrine treatment guidance referred to in the document is here

(I can only access the abstract), but it concludes with:

Clinicians should avoid harming individuals (via hormone treatment) who have conditions other than gender dysphoria/gender incongruence and who may not benefit from the physical changes associated with this treatment.

www.ncbi.nlm.nih.gov/pubmed/28945902

The effects of testosterone on a woman's voice are noticeable because it changes the pitch, but not the timbre. They are 2 different qualities. Vocal training can teach you to change your pitch, as its controlled by tension in the vocal chords and muscles of the throat and mouth. Timbre is a result of the size and shape of the voicebox.

To visualise it, think of a double bass and a violin. Pitch is controlled by tension on the strings, timbre by the size of the body of each instrument. If you could switch the strings over, you could still recognise the instrument.