What is progesterone?
Progesterone is a hormone that stimulates and regulates important functions, playing a role in maintaining pregnancy, preparing the body for conception and regulating the monthly menstrual cycle. Progesterone is one of the hormones in our bodies that stimulate and regulate various functions. Progesterone plays a role in maintaining pregnancy. The hormone is produced in the ovaries, the placenta (when a woman gets pregnant) and the adrenal glands. It helps prepare your body for conception and pregnancy and regulates the monthly menstrual cycle. It also plays a role in sexual desire.
During the reproductive years, the pituitary gland in the brain generates hormones (follicle-stimulating hormone [FSH] and luteinizing hormone [LH]) that cause a new egg to mature and be released from its ovarian follicle each month. As the follicle develops, it produces the sex hormones estrogen and progesterone, which thicken the lining of the uterus. Progesterone levels rise in the second half of the menstrual cycle, and following the release of the egg (ovulation), the ovarian tissue that replaces the follicle (the corpus luteum) continues to produce estrogen and progesterone.
What is the role of progesterone in Women?
One of progesterone’s most important functions is to cause the endometrium to secrete special proteins during the second half of the menstrual cycle, preparing it to receive and nourish an implanted fertilized egg. If implantation does not occur, estrogen and progesterone levels drop, the endometrium breaks down and menstruation occurs.
If a pregnancy occurs, progesterone is produced in the placenta, and levels remain elevated throughout the pregnancy. The combination of high estrogen and progesterone levels suppress further ovulation during pregnancy. Progesterone also encourages the growth of milk-producing glands in the breast during pregnancy.
High progesterone levels are believed to be partly responsible for symptoms of premenstrual syndrome (PMS), such as breast tenderness, feeling bloated and mood swings. When you skip a period, it could be because of failure to ovulate and subsequent low progesterone levels.
Does Progesterone Make You Hornier?
Researchers have repeatedly found that higher levels of estrogen have a positive effect on a woman’s sex drive. And that makes sense—after all, countless postmenopausal women can attest to the efficacy of estrogen therapy in restoring their sex drive. However, the impact of estrogen on sexual desire is not about estrogen alone.
Estrogen and progesterone levels rise and fall throughout the reproductive cycle. But they don’t rise and fall in unison. Rather, their proportions change to guide reproductive processes—the preparation of the uterine lining, ovulation, menstruation, etc. These changing proportions also have a significant effect on sex drive. As one study by researchers at the University of California, Santa Barbara notes, “With respect to within-cycle, day-to-day fluctuations in subjective desire, we found evidence for positive effects of estradiol and negative effects of progesterone.”
These findings are logical from a biological perspective, as estrogen is dominant and increases significantly prior to ovulation. Having a strong desire for sex at this point in the menstrual cycle greatly increases the chance of pregnancy. After ovulation, however, estrogen falls sharply. And while it does begin to rise again in the days following ovulation, so too does progesterone—and progesterone levels begin to exceed estrogen. During this phase of the cycle, many women find that their sex drive diminishes. After all, there is no reproductive advantage to sex during this part of the menstrual cycle. And while humans are not entirely beholden to biology and our relationships with sex and desire are infinitely complex, biology can and does continue to play a vital role in our lives.
Without adequate estrogen, your body may not be receiving the signals it needs to desire sex. For women who are struggling with low sex drive, it is therefore worth examining whether the relationship between estrogen and progesterone has become unbalanced.
Progesterone levels in males are similar to those of females in the follicular phase of the menstrual cycle, when the egg follicle on an ovary is preparing to release an egg.
Symptoms of low progesterone in males include:
• Low libido
• Hair loss
• Weight gain
• Gynecomastia, which is breast development in males
• Erectile dysfunction
• Bone loss
• Muscle loss
Men with low progesterone levels have a higher risk of developing:
• Prostate cancer
• Prostatism, an obstruction of the bladder neck, typically associated with an enlarged prostate gland
As males age, testosterone begins to decline, estrogen levels rise, and progesterone levels fall dramatically.