What Causes Low Progesterone?
Progesterone is a sex hormone released from the ovaries that is vital for conceiving and maintaining a healthy pregnancy. The hormone can be broken down as, ‘pro’ meaning to promote and ‘gesterone’ meaning gestation or pregnancy. Progesterone has 2 different paths each month depending on fertilization. If your egg is fertilized, then progesterone rises after ovulation to help thicken the uterine lining for pregnancy. If your egg does not become fertilized after ovulation, then progesterone peaks and then declines, because you do not need to prepare for pregnancy. The uterine lining will shed and become a period. Problems can arise when progesterone levels are too low when you are trying to conceive.
So, what causes low progesterone?
1. Stress
Stress can be what causes low progesterone. When we are stressed we release high levels of cortisol, a stress hormone. In response to this, our body is trying to survive given threatening circumstances, so the body will pump the brakes to avoid pregnancy. This is because our body wouldn’t predict us to be healthy enough to survive a pregnancy under stressful conditions. Stress can be caused from a high pace job environment, family problems, too much exercise, and a common one is stress from the act of conceiving itself.
2. Nutrient Deficiencies
Vitamin B6 may be what causes low progesterone for you because B6 is a vital water soluble nutrient necessary for pregnancy. Without the vitamin, it puts you at risk for developing a healthy pregnancy. Some of its main roles in pregnancy are healthy brain development, curing morning sickness, and immune function.
Source: 6694167
Zinc is another vital mineral for pregnancy, so if levels are low it can be what causes low progesterone. It has been shown that low levels of zinc have been correlated with a longer time to conceive. A large function of zinc is its antioxidant function.
Magnesium deficiency can be what causes low progesterone levels additionally because it is a highly important supplement for pregnancy. Some of its main benefits include increasing fetal development, protein synthesis, and stable nerve cell function.
Source: 6684167
3. Lack of Ovulation
Lack of ovulation, where the egg is not released from the ovary, can be what causes low progesterone levels. If the ovulation does not occur or is irregular, then the body will not think to prepare for pregnancy and progesterone will not be released. Lack of ovulation can occur do to a number of reasons, but a common factor is stress.
Source: 25681845
4. Estrogen Dominance
Estrogen is another sex hormone that is vital for reproduction. It needs to be released in a balance with progesterone for an optimal menstrual cycle. Estrogen should be higher in the first half of the cycle and lower in the second half whereas progesterone is the opposite. Estrogen dominance means that the level of estrogen in relation to progesterone is abnormally high. This can be what causes low progesterone because estrogen is dominating and then your body won’t produce as much progesterone.
Source: Estrogen Book
5. Undereating
Undereating can be what causes low progesterone because this is a form of stress on the body. Undereating refers to decreasing your calorie intake below your energy output per day which can be intentional or not. This can put our body into a state of panic because we are trying to survive at an energy level insufficient for our current size. From this stress, progesterone levels decrease because we are not prepared for pregnancy.
Source: 19007855
6. Overexercising
In addition to undereating, over exercising has a similar effect on the body in terms of progesterone levels. Over exercising can be what causes low progesterone because of the high stress it puts on the body. Over exercising can be identified as any exercise performed at a high frequency and intensity during the week with minimal to no rest days. It is important to note that exercising in general is great and actually beneficial for hormone levels, but it is the excessive nature of exercise that is harmful. The main issue with this is that our bodies need a stable body fat percentage to maintain a normal menstrual cycle. As a rule of thumb, most females need at least 17% body fat to maintain a normal menstrual cycle to ovulate. Ovulation is absolutely necessary for progesterone production. The stress from overexercising can impair ovulation and result in low progesterone levels.
7. Perimenopause
Menopause is defined as a female in her 40s-50s who had her last menstrual cycle at least 12 months ago and no longer gets it anymore. Perimenopause is the process which leads up to this point and can be what causes low progesterone. Irregular periods are common with perimenopause, and therefore correlates with decreased ovulation and low progesterone levels.
Source: Harvard
8. High Prolactin
Prolactin is a hormone in the reproductive system that allows the breasts to produce milk. ‘Pro’ meaning to make and ‘lactin’ meaning lactose or milk. Prolactin is released during pregnancy and after birth to get ready for natural nursing. During postpartum, estrogen and progesterone levels drop because you are no longer pregnant. This is why breastfeeding women have irregular menstrual cycles, because ovulation is harder to achieve from decreased hormone outputs. A cause for having high prolactin levels is if you are diagnosed with polycystic ovarian syndrome or PCOS, and/or having low thyroid mentioned next.
Source: 4092671
9. Low Thyroid Function
Low thyroid or hypothyroidism, can be another reason as to what causes low progesterone levels. The thyroid is a gland in our throat that needs to release hormones to maintain a stable metabolism among other things. If these hormones are not released as frequently as they should, then this is called low thyroid or in more intense situations, hypothyroidism. As mentioned low thyroid and high prolactin have a connection to what causes low progesterone. Our body will try to stimulate more thyroid output, so additional hormones in the brain, specifically the hypothalamus, will be released to try to generate more thyroid hormones. These hormones, unfortunately, can also increase the prolactin production and will therefore decrease progesterone.
Source: 9846161
10. Not Eating Enough Fat
This may seem random, but when you understand the female sex hormones, it makes a valid connection as to why not eating enough fat may be what causes low progesterone. Females in general have a higher body fat composition than men because females need the extra fat for carrying a fetus through pregnancy. Our reproductive hormones naturally release in response to if this percentage is too high or too low. If you are not eating enough fat, then this can decrease the absorption of fat soluble vitamins, and decrease body fat percentage which signals to the body that we are under stress or potentially under eating. Sex hormones are also produced from cholesterol, making adequate healthy fat consumption absolutely crucial for healthy hormone production. This is why not eating enough fat can be what causes low progesterone. Healthy fat sources include, fish, avocado, nuts, and seeds.
Source: 26843151
11. Luteal Phase Defect
The luteal phase is the second half of the menstrual cycle where progesterone usually increases when the egg is fertilized. The follicular phase is what happens in the first half of the menstrual cycle and then once ovulation happens, the luteal phase takes place. A defect in this luteal phase is a factor that will disrupt the menstrual cycle. Examples of a defect could be high prolactin as mentioned earlier, obesity, PCOS, and low thyroid hormone production. All of these factors can be what causes a luteal phase defect and what causes low progesterone.
Source: 26585269
12. Irregular Periods
Irregular periods occur due to a variety of reasons, but what is really happening is a lack of normal ovulation. As mentioned before a lack of ovulation, and irregular periods can be what causes low progesterone levels because you are not prepared for pregnancy. Some reasons for irregular periods can be stress, PCOS, not eating enough, or coming off of oral contraceptives.
Source: 25681845
Take away message:
There are several causes of low progesterone levels. If you’re looking to understand the root causes of your low progesterone, check out my hormone testing packages HERE.
Be sure to check out my FREE hormone guide & 5-day meal plan below for more hormone balancing tips. And my online course Heal Your Period: Everything you need to know to achieve a regular, pain-free period.
