Basic Science on TransHub

What are steroid hormones?

Mon, 01 Jan 0001 00:00:00 +0000

Sex hormones such as estrogens, androgens and progestogens, are all “steroid hormones”. This page describes the role of hormones, and the subgroup of steroid hormones.

First of all, what are hormones? Hormones are chemical substances produced by the body, and functioning as a messenger between organs. There is usually an organ that produces and an organ that receives. You can think of hormones as the wireless counterpart of the nervous system. It connects parts of the body remotely, to give them various orders; and it is much slower than the wired nervous system. Some common and known hormones that act as neurotransmitters are dopamine, serotonin, oxytocin, melatonin… Closer to our topics, we find the GnRH (Gonadotropin Releasing Hormone), FSH (Follicle Stimulating Hormone) and LH (Luteinizing hormone). Those last three, as we’ll see, play an important role in controlling sex hormones, and we’ll see what we can do with that.

Sex Hormones: how do they work?

Mon, 01 Jan 0001 00:00:00 +0000

The hormones that interests us for trans HRT are sex hormones. Those are an informal subgroup of steroid hormones. We’ll discuss here how hormones have effects on our bodies, and learn about the importance of “receptors”.

And first, what are they? As we said before, sex hormones is a group that covers 3 subgroups of steroid hormones: androgens (among which the famous testosterone), estrogens (estradiol will be our main friend for feminizing HRT), and progestogens (progesterone is the main naturally occuring one). That’s why they are sometimes called sex steroids, but also gonadal steroids, since they are mostly produced in our gonads: testes and ovaries.

The different estrogens, androgens and progestogens, and their binding affinity

Mon, 01 Jan 0001 00:00:00 +0000

When we speak of estrogens, we don’t refer to only one hormone. Estrogens, as well of androgens and progestegens are three groups, each covering similar yet different hormones. Knowing about those differences is important in many ways.

Let’s speak first of binding affinity. Binding affinity designates the ability and “ease” with which one hormone will bind to its receptor. If we use the key and keyhole metaphor, you can imagine that several keys can open the same lock, but some will enter and turn with much difficulty, when others will do it quite smoothly. This is binding affinity: it is high when the key gets in without effort, and opens efficiently, and it is low when the key can open the lock, but not without effort. The different kinds of each sex hormone come with different binding affinity, which is why we will prefer some over others for efficient feminization/masculinization.

The self-regulation mechanism, and how to use it in our benefits

Mon, 01 Jan 0001 00:00:00 +0000

The negative feedback mechanism is a normal and “natural” biological function of the endocrine system that regulates the production of sex hormones, so that we don’t end up with too much or too little. Knowing about this mechanism is key to understanding many methods of HRT, and the way some medications work.

If the body naturally and continuously produces sex hormones, why don’t we end up with too much of them? Well, obviously because the body is smart and able to self-regulate the production. And understanding the way it does that can help us understand and choose better the ways of our medical transitions (at least for transfeminine people).

Growth hormones

Mon, 01 Jan 0001 00:00:00 +0000

Growth hormone is not a sex hormone. It does, however, play a role in feminization/masculinization during HRT, as it plays a fundamental role during puberty. This page is aiming at informing you about it, and proposing ways to naturally stimulates its production. But it is also a strong warning not to try and take exogenous growth hormones.

A hormonal factor that is not often addressed is the role of growth hormones. As its name states, growth hormone is a key component in tissue growth and repair. It is released in a pulsatile way (at a regular time in the day - actually usually at night during sleep), and its average levels vary in the different stages of life. High during childhood and puberty, they decrease in our twenties. After that, their levels are dependent on the needs: spurts will occur after body traumas in order to stimulate healing, or after intense physical activity (which actually creates many little muscle traumas). In the frame of medical transition, you could compare the role of growth hormones to the role of building workers when sex hormones are the architects. Sex hormones decide what and where to build, growth hormones do the actual building.

DHEA and intracrinology

Mon, 01 Jan 0001 00:00:00 +0000

DHEA is the hormone found in largest quantity in the human body. It has a very weak masculinizing effet in itself, but its action is mostly due to its conversion into testosterone and DHT in and by target cells. Intracrinology is the subfield of endocrinology who looks at this phenomenon, and it can matter to us (mostly transfem people) for a number of reasons.

As we have explained, most of our sex hormones are produced in our gonads: ovaries and testes. That means that in case of surgical removal of the gonads (orchiectomy/vaginoplasty, ovariectomy…), the vast majority (95%) of our sex hormones circulating in the body will be gone. This also means that after such surgery, transfem people on HRT could stop taking anti-androgens.