What is progesterone and how does it work?
Progesterone acts in several directions, causing metabolic and physical changes that would prepare a woman’s body for bearing a child. His name he received because of this quality (“hormone for pregnancy”). In pregnancy, the level of progesterone is fifteen times greater than during the entire menstrual cycle. In the first half (the phase of follicle formation), the level of progesterone produced is “very small and is at the level of 0.3-0.9 ng / ml.” When ovulation begins, the egg is secreted and becomes a yellow body that starts to synthesize progesterone. “The level of progesterone in the second (luteal) phase of the cycle increases to 15-30 ng / ml, which is thirty times higher than the content during the first part of the cycle.
Progesterone emitted by the yellow body stimulates thickening of the uterine wall and makes it secretory so that it can take a fertilized egg and ensure its growth. If fertilization occurs, the placenta becomes a small “factory” for the production of hormones and starts throwing out high doses of progesterone throughout pregnancy. If we take into account all the numerous changes necessary for a woman’s body to carry a child, then it is not surprising that progesterone has multiple effects on the whole organism, and not only on the reproductive organs.
Progesterone can also act on the body’s ability to store fat, but more on this later. This process is observed in many species, not only in humans. The ability to store fat is an advantage that has developed over a long evolutionary process. It ensures the survival of the mother and child, because the body makes sure that the mother has enough fat deposits that will be useful for nine months of bearing the child for cases of famine. For millions of years of human evolution in times of food shortage, those women who best extracted food from nutrients and stored fat were able to reproduce and were able to multiply. As a result, our body, under the action of progesterone, has adapted to extracting the greatest amount of nutrients from what we eat, even if there is little food. This hormone stimulates our appetite and cravings for food containing carbohydrates, which in turn are used as energy and are stored as fat. But alas, we live in a time of universal abundance, and our ability to store fat becomes a curse!
In addition to the effect on fat deposition, progesterone can relax the smooth muscles of the intestinal tract. In this case, the movement of food through the stomach and intestines slows down, and nutrients are absorbed more fully. When bearing a child, this is a positive quality. If we are not pregnant, then the slowing of the bowels is manifested as swelling, fullness and constipation (especially if you do not consume enough fiber), and if this is combined with a sluggish gallbladder, there is a risk of stones forming in it. “Slow down” also means that more calories are extracted from each piece you eat, this is our difference from men who quickly skip food through the stomach and intestines and whose body does not absorb all of the calories.
Progesterone and progestins: it’s important to understand the difference
We know that the functioning of steroid hormones is strongly affected by even a slight change in the molecule. The number of carbon atoms, side chains, unsaturated chemical bonds, the addition of other atoms – all this can very strongly transform the mechanism of the hormone in the human body. Minor changes in molecules change the desired result and can cause unnecessary side effects.
Progestogen – a general term used to describe any substance that has a biochemical ability to promote the bearing of a child, or the so-called “progestational” quality.
Progesterone (present in the human body and all vertebrates) is a natural biological progestogen. Human progesterone is produced mainly by the yellow body after ovulation, as well as by the placenta during pregnancy. A small amount of progesterone is produced by the adrenal glands, but in order to prepare the body for pregnancy, this is not enough.
Progestins are man-made chemical molecules whose structure is different from the molecules inherent in the human body. Their properties and effects are similar to the action of progesterone, but since their molecules have a slightly different composition, there are also a number of other properties, and in some cases they are even more potent than natural progesterone. As a result, progestins function differently in the body. Sometimes it is necessary and only welcomed, but sometimes it gives a lot of worries.
The use of synthetic progestins, especially medroxyprogesterone acetate (MPA), is the most common cause of unpleasant side effects associated with hormone therapy, and among them the addition of extra pounds. There are two main factors determining the balance of the desired and undesirable side effects: the balance of progestin and estrogen in the preparation and the relative balance of the functioning of progestogens and androgens. Preparations containing only progestin, in which there is no estrogen (norplant, depo-provera), usually cause the most unpleasant side effects, because the negative effect of the progestin is not compensated for by the benefits that the organism brings to estrogen.
Why use synthetic progestins, if they cause so many side effects? There are situations and women to whom synthetic progestins are useful or they do not have very many side effects. Some women experience a feeling of hunger after taking natural progesterone, but this is not observed if they use norethindrone (contained in a micronor and some birth control pills). All this is very individual. In order to choose the best option, we need to take this into account.
How progesterone works on the body
The effect of progesterone on metabolism
Rapid change of hormones during the menstrual cycle and the balance of estradiol and testosterone affect the multiple metabolic functions on which weight regulation depends. Among them – the deposition and use of carbohydrates and fats, the rate of emptying the stomach, the release of insulin, the production of cortisol, the cleavage of caffeine and proteins, the craving for food and the effect of hormones on the operation of the gallbladder and the immune system. Progesterone and estradiol together regulate fat stores in your body, build muscle and restore it, and build. In part, they do this by changing the activity of the lipoprotein lipase (LPL) enzyme contained in fat cells (adipocytes). To reduce body fat (obesity), estradiol reduces the activity of LPL, while progesterone increases fat reserves for possible bearing of the baby, increasing the activity of LPL enzyme, respectively. And you still wonder why a woman is harder than a man to lose weight, even with diligent sporting activities!
Estradiol and progesterone control the release of insulin in response to the intake of glucose. In animals and humans, both these hormones increase the release of insulin from the pancreas after ingestion, but in other tissues, estradiol and progesterone differently affect insulin susceptibility. Insulin susceptibility is how well insulin receptors react to insulin and do not allow a sharp release in response to the intake of glucose into the blood. Progesterone decreases insulin susceptibility and prevents normal regulation of glucose. Progesterone quickly acts on insulin, and this effect can be detected within 10 minutes after taking the hormone. It turns out that progesterone most directly affects the pancreas. This is one of the reasons why pregnant women often have a craving for sweets, which, incidentally, occurs in the second half of the menstrual cycle, when the level of progesterone increases. Women with diabetes are particularly sensitive to the property of progesterone to increase blood sugar, so they should use this hormone in minimal doses.
Estradiol, by contrast, increases insulin susceptibility and improves glucose tolerance in humans and animals. The positive effect of estradiol on the regulation of glucose in the body was noted in women of both pre-menopausal and post-menopausal age, with external application of estradiol. Women with diabetes have also been shown to improve with such an application of estradiol. Fatty (adipocytes) and muscle cells do not respond to the use of estradiol, increasing insulin susceptibility. But improvement is manifested in many ways, and one should not talk about direct effects on the pancreas.
With the normal menstrual cycle and the optimal content in the body of hormones, the opposite actions of estradiol (E) and progesterone (P) are usually compensated each other. It turns out that the ratio E: P is more important for the total effect of metabolism. In women who came to me to assess the level of hormones in the body, the E: P ratio was taken as a basis, which helped determine the severity of the symptoms and the time through which the patient feels better. If during the luteal phase in the body the level of estradiol is below normal, but the level of progesterone is normal, then women had a stronger craving for sweets and more intensive weight gain.
Prolonged use of progesterone without proper application of estradiol worsens insulin susceptibility, which leads to an increase in fat accumulation in the waist region, an increase in the level of cholesterol in general, a decrease in the amount of “good” cholesterol (HDL) and an increase in “bad” cholesterol (LDL), and triglycerides TG). Insulin susceptibility also causes an increase in blood pressure and significantly increases the risk of heart disease due to the formation of plaques in the arteries. Since the consequences of reducing insulin susceptibility can be very serious, it can be considered as a decisive factor in assessing the condition of women who are overweight. This will help to find out what hormones are needed for the body, determine the form of their use – orally or through the skin.
Effects of progesterone on muscle and connective tissues
The metabolism of muscle protein and the degree of destruction of muscle tissue are affected by hormonal changes throughout the menstrual cycle. These values can be assessed by examining the breakdown products of the protein, for example, urea in the urine in the middle phase of follicle formation (elevated estradiol content) or in the middle of the luteal phase (high content of progesterone). A very high level of urea in the urine indicates a stronger muscle breakdown, usually in the middle of the luteal phase of the cycle. If there is an increase in the ratio of progesterone to estradiol, then the face is more decay (catabolism) of the muscle protein of the body. Women who have more fatty tissue in their body than muscular tissue, as well as women who feel pain in the muscles, should be careful when taking progesterone without replenishing estradiol, as it can provoke excessive muscle protein breakdown and destruction of muscle tissue. Remember, when you lose muscle, you are depriving yourself of the most effective mechanism for burning calories.
Canadian researchers found that women 20-30 years in the period of ovulation have the highest muscle strength, as the level of estradiol reaches the highest level. In the luteal phase (the period of high content of progesterone) or during the bleeding period (low estrogen), muscle strength decreased. With menopause muscle strength is greatly reduced, unless a woman undergoes hormonal therapy, but after menopause in women who use estrogen, muscle strength was not decreased. These studies say that if you do not want to lose muscle mass and increase the amount of fat, you should avoid the use of progesterone in more than necessary to prevent thickening of the uterus wall, the amount.
An interesting effect of progesterone on the connective tissue, from which the ligaments and tendons in our body are composed, is also noted. They are a special concern for women who gain weight. For example, during pregnancy, a high level of progesterone helps to prepare the pelvic ligaments to relax during labor to ensure the expansion of the pelvic bones for the passage of the child through the birth canal. However, relaxed ligaments, as you probably know, can cause pain in the back and legs in the last three months of pregnancy. But even if you were never pregnant, you could feel this discomfort in the second half of the menstrual cycle, when the level of progesterone is quite large. This is one of the reasons why female athletes get more injuries during training during the phase when progesterone dominates, rather than when there is a lot of estradiol and little progesterone.
But what if you weigh more than the norm? If your body has progesterone, in comparison with estradiol, more – due to a decrease in the level of natural estradiol or because of hormone replacement therapy – you will also have ligaments relaxed. Such a negative property in combination with excess weight can provoke even more severe pain in the back, legs and ankles. High doses of synthetic progestins cause malaise similar to these.
This is another reason why women with excess weight follow the hormone levels during the phase when progesterone dominates and avoid taking too much progesterone with hormone therapy or contraceptive pills (such as aleszi, myrsett or loestrin).
The action of progesterone on the immune system
Another important manifestation of progesterone is the ability to suppress the immune system. Perhaps this is one of the reasons that women with allergies or herpes have outbreaks of these diseases every month during the phase when progesterone dominates. During pregnancy, the ability of progesterone to reduce the intensity of the immune system does not allow the mother’s body to “attack and destroy” the foreign protein of the developing fetus, which contains the genetic structure of the father and the protein code system. For a pregnant woman, this function of progesterone is very important, but if you do not have a baby, you do not need to suppress the immune system. In the regulation of body weight and metabolism, many chemical messengers are also involved, which normalize the functioning of the immune system, so if you are trying to lose weight, you do not need any negative consequences.
Effects of progesterone on sleep
Estradiol, produced before menopause, is one of the most important hormones that regulate the sleep center in the brain and provides a normal phase flow of sleep. When estradiol ceases to be produced, normal sleep is interrupted, and especially this is characteristic of the 4th phase, the phase of the deepest sleep. Therefore, for women who need to restore normal sleep and muscle tissue, it is very important to maintain a normal level of estradiol in the body. The effect of progesterone on sleep differs from the action of estrogen, so that in the restoration of sleep progesterone estradiol can not be replaced, despite the fact that some books claim the opposite. However, there are some intermediate metabolic products that have a powerful sedative effect, very similar to that of barbiturates and benzodiazepines. One of the progesterone decay products, Z-alpha-OH-DHP, is almost eight times stronger than the sedative drug called methohexital, a powerful barbiturate used in anesthesia. For the conversion of progesterone into these soothing components, the liver is responsible, so the sedative effect of progesterone will be noticeable when it enters the body through the oral cavity and will be first treated in the liver.
Progesterone in the same way affects the brain, affects the same receptors responsible for sleep, as some drugs: clonopine, ativan, ambien, xanax, valium, etc. Since progesterone causes drowsiness, it can sometimes be a useful adjunct to hormone therapy , even if you have removed the uterus. But it is necessary to observe a balance so that such undesirable, knowingly negative side effects, such as the acquisition of extra pounds, do not appear.
Interaction of progesterone with growth hormone, insulin and cortisol
Progesterone lowers the level of GH, increases the level of insulin and increases the production of adrenal cortisol. The process of metabolism in this case occurs in the same scenario as in excessively full people, with Cushing’s disease (excess cortisol) and after taking corticosteroids (for arthritis or asthma). With such a metabolism, you become fuller, so this therapy should not continue. In addition, GH causes a greater increase in non-fatty tissue, for example, muscle and bone, and reduces the body fat content. One of the reasons why some doctors prescribe GH to older people is that it increases muscle mass. Therefore, anything that lowers the level of GH, namely that we become older or use the wrong hormones, leads to an increase in the amount of fat.
High levels of progesterone, like during pregnancy or PMS-therapy, during which large doses of the hormone are used, are associated with an increase in the level of unbound (free) cortisol in the blood. It reduces the content of GH and causes the release of a large amount of insulin and a greater insulin susceptibility. This is another reason that the regular use of progesterone in doses that increase the level of the hormone in the blood to the limits of pregnant women can adversely affect the health of a non-pregnant woman. Such changes, caused by a high level of progesterone, can disrupt the normal production of GH, insulin, cortisol, which in turn will lead to overweight, changes in blood sugar levels, increase the risk of diabetes, abnormal cholesterol and many other problems.