Transmasc Hormone Science 101
I'm curious to learn more about the specifics of different T preparations and methods, esp in terms of varying results. As far as I can tell, the assumption is that they're identical - they produce some masculinisation which is presumed to be what all transmasculine people ultimately want. But they don't - we're individuals - and so I'm interested to learn what, if anything, we can do to customise our outcomes more
All of these studies are of cis men, unless otherwise stated; some are cis men with particular conditions, or who are elderly, or part of particular groups. This may or may not be applicable to us. At the level I'm capable of, I can't say whether these impact transmasc people significantly or at all - but they are interesting, let's say. Experiment with as you wish.
Initial search: transgender testosterone on Pubmed, going back 5 years.
Reproduction
10.1210/endocr/bqaa014
Discussion of what we know
Unfortunately, in regards to best practices surrounding fertility treatment and/or fertility preservation in transgender men, there seem to be more questions than answers from the available literature....As such, the current status quo is to recommend fertility preservation before initiation of T therapy and, for patients presenting subsequent to T therapy, cessation of T before ovarian stimulation....The long-term goal should be to equip medical providers with the information necessary to provide high-quality, data-driven counseling regarding fertility options for transgender men.
Other
10.1089/andro.2021.0008
irk. Is this study for real? I have no idea what, if anything, this means for us. Congrats on having a bigger brain, I guess; you were right, The Patriarchy!
Testosterone produces structural changes in the brain as detected by quantitative magnetic resonance imaging. Mainly, it induces an increase in cortical volume and thickness and subcortical structural volume probably due to the anabolic effects.
10.1016/j.psyneuen.2022.105751
I've heard through the grapevine that people with a uterus still feel monthly dysphoric peaks, following the ghost of their menstrual cycle. This study stood out as apparently validating this sense - our ability to complete logic tasks is cycle-dependent. I like that the study notes its intention is NOT to normalise like, cissexist frameworks around sex or gender, but to call for a deeper understanding of our hormonal situation.
Performance of TM- varied across the menstrual cycle, and matched that of menstrual phase-matched CW. Additionally, cycling individuals in Follicular performed as strongly as TM+ and CM, all of whom performed above individuals in Luteal...Rather than conforming to static categories that suggest sex- or gender-typical organization of cognitive circuits, our findings support dynamic shifts in visuospatial ability of TM, and illustrate the need to consider activating effects of hormones beyond GAHT
Social
10.1016/j.jsxm.2018.03.079
Testosterone therapy was not associated with an increase in levels of aggression in transgender men...but other psychological and/or social factors, such as anxiety levels, appear to contribute to self-reported aggression in transgender people
10.1016/j.jsxm.2017.11.004
This study demonstrates that during 7 months of continuous gender-affirming hormonal treatment, anger expression and anger arousal control increased in transmen. Persistence of menstrual bleedings and Axis I disorders, but not circulating testosterone levels, were predictive of the increase in anger expression score. Continuous psychological support to transmen during gender-affirming hormonal treatment was useful to prevent angry behaviors and decrease the level of dysphoria...Interestingly, despite the increase of anger expression scores, during continuous testosterone treatment, there were no reports of aggressive behavior, self-harm, or psychiatric hospitalization.
This is the second study on this topic I've read which noted that the persistence of menses is more likely to be linked to more aggression; I guess, people who are still in hormone flux or too low hormones to have fixed their dysporia are more stressed, perhaps?
0.1016/j.jsxm.2019.12.020
Transgender people can be informed that changes in sexual desire after initiating HT are temporary. Over a longer period of time, the current research does not suggest...long-term increased sexual desire in TM.
10.1016/j.yhbeh.2019.02.016
State-level anger intensity is associated with psychological and/or psychiatric vulnerability, but not exogenous testosterone therapy or serum testosterone levels in transgender people.
10.1016/j.yhbeh.2020.104912
Four out of seven studies reported an increase in aggression-related constructs, while one study reported a decrease. In all studies reporting changes, the follow-up period was less than 12 months, indicating that gender-affirming testosterone therapy could have a short-term impact on aggression-related constructs. However, the available studies carried a risk of bias, which indicates a need for further research.
https://doi.org/10.1016/j.psyneuen.2022.105928
Going on T makes transmascs understand the emotions in faces more like cis men do than like cis women do. I uh would love to read this one and get a better sense of the study - how significant was this...?/p>
10.1007/s40618-022-01835-1
The other day I idly mused - half-joking - that perhaps the bigots have it the wrong way around, and gender dysphoria causes autism. This suddenly struck me as far too potentially true and I shelved that thought at once. So this article leapt out at me. It seems to agree with my own experience and what I was considering, which is that a lot of issues I had which I put down to ADHD-Autism have receded or become more manageable as a result of hormones. This is all very chicken and egg - does it make me nonautistic if I'm asymptomatic now? do i just have less on my plate to manage, as an autistic person, now my dysphoria is handled? Or? idk. Many ways to articulate this phenomena depending on the framing which seems right to you.
The autistic traits in our sample may represent an epiphenomenon of GD rather than being part of an Autism Spectrum Disorder (ASD) condition, since they significantly decreased after 12 months of GAHT (Gender Affirming Hormone Therapy).
Hormones improve quality of life
Hair
10.1111/jsm.12366
Looked at acne, male-pattern baldness, and body hair. Acne peaks at 6 months and is no issue longterm; ~30% of trans men after 10 years will have some kind of hairloss, but no one in the first year; and all but one were body-hairy longterm. They did not find results was related to a person's T or DHT levels.
Safety
10.1210/clinem/dgab089
Erythrocytosis is not a Greek fury, but the thing that leads to blood clots, deep vein thrombosis etc. This article was the subject of Letters to the Editor about whether hrt for trans men should therefore be prevented entirely, whether high BMI and smoking trans men should be prevented from having hormones, with the study authors defending the challenge that they ought to have assessed their patients using female reference ranges not male ones. Trans medicine, bro: I hate it here.
Erythrocytosis occurs in trans men using testosterone. The largest increase in hematocrit was seen in the first year, but also after the first years a substantial number of people present with hematocrit > 0.50 L/L. A reasonable first step in the care for trans men with erythrocytosis while on testosterone is to advise them to quit smoking, to switch to a transdermal administration route, and if BMI is high, to lose weight.
What they don't say here is they also found a raised risk in the long-acting undecanoate.
10.1016/j.jsxm.2021.06.011
TM persons may experience modest increases in ALT and AST concentrations following testosterone initiation; however, clinical significance of the observed association remains unclear and requires further investigation...The influence of long-term GAHT on ALT and AST levels appears modest and not likely to reflect clinically meaningful changes in liver function.
Social
Prospective Evaluation of Self-Reported Aggression in Transgender Persons (2018)
10.1016/j.jsxm.2018.03.079
Does Testosterone Treatment Increase Anger Expression in a Population of Transgender Men?
10.1016/j.jsxm.2017.11.004
This is the second study on this topic I've read which noted that the persistence of menses is more likely to be linked to more aggression; I guess, people who are still in hormone flux or too low hormones to have fixed their dysporia are more stressed, perhaps?
Sexual Desire Changes in Transgender Individuals Upon Initiation of Hormone Treatment: Results From the Longitudinal European Network for the Investigation of Gender Incongruence (2019)
0.1016/j.jsxm.2019.12.020
No correlation between serum testosterone levels and state-level anger intensity in transgender people: Results from the European Network for the Investigation of Gender Incongruence (2019)
10.1016/j.yhbeh.2019.02.016
Effects of testosterone therapy on constructs related to aggression in transgender men: A systematic review (2020)
10.1016/j.yhbeh.2020.104912
Gender-affirming hormonal treatment changes neural processing of emotions in trans men: An fMRI study
https://doi.org/10.1016/j.psyneuen.2022.105928
Going on T makes transmascs understand the emotions in faces more like cis men do than like cis women do. I uh would love to read this one and get a better sense of the study - how significant was this...?/p>
Apparent autistic traits in transgender people: a prospective study of the impact of gender-affirming hormonal treatment
10.1007/s40618-022-01835-1
The other day I idly mused - half-joking - that perhaps the bigots have it the wrong way around, and gender dysphoria causes autism. This suddenly struck me as far too potentially true and I shelved that thought at once. So this article leapt out at me. It seems to agree with my own experience and what I was considering, which is that a lot of issues I had which I put down to ADHD-Autism have receded or become more manageable as a result of hormones. This is all very chicken and egg - does it make me nonautistic if I'm asymptomatic now? do i just have less on my plate to manage, as an autistic person, now my dysphoria is handled? Or? idk. Many ways to articulate this phenomena depending on the framing which seems right to you.
Hormones improve quality of life