Effects of Birth Control Pills on the Hormonal Systems

This month I am writing on a topic that I often get questions about:  what are the effects of birth control pills (made of synthetic hormones) on my body?  Recently, I came across an excellent scientific article on this topic full of references for all the data stated here.  I am grateful to those authors and credit them. You can find that article in the link below.

Hormones are the regulators of our body systems and the functions they provide. These include regulating mood, reproductive health, and the general balance of all the other body systems to prevent imbalance and disease. Hormones must generally stay in balance over the long term to create good health.  Most of our hormonal system regulation is interactive between our hypothalamus-pituitary-adrenal-thyroid-gonadal (ovaries/testes) axis in the body. It is very sensitive to any endocrine imbalance.

Factors such as our environment, lifestyle, and genetics influence this delicate balance. The birth control pill (BCP) is one of the most common causes of upsetting this interdependent balance between adrenals, thyroid, and ovaries.  BCP’s are used to prevent pregnancy and to treat many hormonally caused diseases/conditions from PMS (pre-menstrual syndrome) and acne, to PCOS (polycystic ovary disease).

BCP’s include estrogen and progesterone analogues (i.e., Ethinyl estradiol and progestin) but differ from the body’s natural hormones (or bio-identical hormones).  This conflict creates different risks.

Low estrogen is associated with increased susceptibility to cardiometabolic disease like obesity, diabetes, and cardiovascular disease.  Too much creates a state called estrogen dominance with effects way beyond tissues considered to be responsive to estrogen (breasts, ovaries, uterus).  Any estrogen-mimicking molecule, like BCP’s and environmental toxins/xenoestrogens, makes this state more likely.  If this condition continues over the length of time, it negatively contributes to conditions such as breast and ovarian cancer, uterine fibroids, endometriosis, PCOS, and infertility.

The part of the BCP which prevents pregnancy is synthetic progesterone, called progestin.  It is not an exact match molecularly to our body’s naturally produced progesterone and has different actions in the body. 

BCP’s affect our adrenal glands, causing mal-adaptive reactions.  These include increases in resting cortisol and blunted cortisol responses to stress.  Compared to women not on BCP’s, those using BCP’s showed significantly altered cortisol rhythms. (See previous articles on my website on the adrenals for details of symptoms these imbalances cause. Insert link)  These impairments can lead to anxiety, depression, reduce learning and memory, and trigger disease development. Monitoring and addressing adrenal status can be very helpful to any BCP user.

BCP’s have effects on the thyroid gland.  The thyroid plays a vital role in the ovaries and reproductive health.  BCP’s produce a protein that binds free thyroid hormones which may increase the need for thyroid medication to provide adequate FreeT4 (a thyroid hormone) and ultimately FreeT3 (another).  BCP use has been connected with users sometimes having larger than normal thyroid glands. Commonly, BCP users have low levels of the essential minerals for the thyroid, zinc, and selenium.  Symptoms related to low thyroid function include fatigue, weight gain, constipation, depression, cardiovascular disease. Every woman on BCP’s should be tested for thyroid function and treated appropriately.  (See previous articles I have written on this subject on the website. Insert Link )

BCP’s effects on the ovaries.  When on BCP’s 1 in 5 users report they experience low libido, vaginal dryness, pain with sex, and discomfort of the vulva.  Also, many experience muscle loss and metabolic changes leading to weight/fat gain.  These are most likely the effects of lowered testosterone levels caused by the BCP’s. The synthetic “progesterone,” progestin in the BCP reduces testosterone production by 60%.  Also, BCP’s increase production of a protein that binds with testosterone making it ineffective (See other articles on testosterone effects on the website.) In patients with acne and PCOS, these “side effects” have some benefit but often with the associated symptoms of sexual dysfunction above.

Furthermore, studies have shown that discontinuing the BCP’s may not reverse these effects.  More research is needed to understand why.  But, potential long term negative effects on sexual, metabolic, and mental health are possibilities in some BCP users due to its effect on testosterone.

Birth control is a necessary choice for women of childbearing age. And, I encourage you to look at and consider all the options available before just automatically going onto BCP’s.  (Especially evaluate the IUD without progestin.) Consider the short and long term consequences of what you are doing and make the best-informed choice for you.  If you or someone you know is on BCP’s, I encourage you to get your adrenals, thyroid, and nutrients checked with a Functional Medicine clinician who can help you keep those hormonal systems balanced.  My staff and I are available for this or any support you may need.

Happy fall to everyone!

Jane