Connection Between Oral Contraceptives and Elevated SHBG – Part 2

Welcome to Part 2 of my series about birth control pills and unintended side effects. Be sure to check out Part 1, where I cover birth control basics and some pros and cons of oral contraceptives. 

Today I want to focus on one specific birth control pill side effect that’s rarely discussed: elevated sex hormone binding globulin (SHBG). High SHBG affects hormone levels, blood clotting risk, and overall health. 

Keep reading to learn more about:

• How the pill affects testosterone in women
• How the pill might differ from other forms of hormonal birth control 
• What symptoms of low testosterone may look like 
• The risks of elevated SHBG
• Non-hormonal birth control options

Let’s get started! 

How Oral Contraceptives Affect Androgens in Women

Androgens, including testosterone, are the group of hormones typically thought of as male. Yet, testosterone and other androgens in females are also critical for health and hormone balance. 

To understand the relationship between birth control pills and androgens, we need to understand sex hormone binding globulin. SHBG is a protein made by the liver that binds to testosterone (and estradiol, your primary estrogen). This binding helps regulate hormone levels. When testosterone is bound, it’s unavailable for use in the body. Only free testosterone can act on your cells. (You can read more about SHBG here).

Birth control pills cause low testosterone. This happens in two ways. First, the pill suppresses testosterone production in the ovaries and adrenals, so you make less testosterone when you are on the pill. 

Birth control pills cause low testosterone. This happens in two ways. First, the pill suppresses testosterone production in the ovaries and adrenals, so you make less testosterone when you are on the pill.

Second, the birth control pill increases SHBG by as much as 250%! With a dramatic increase in SHBG, more testosterone is bound up and unavailable for use. Free testosterone can decline by as much as 60% when using hormonal birth control, depending on the type of hormonal birth control.  

IUD and Patch Birth Control

The form and strength of hormonal birth control may impact SHBG differently. 

IUD birth control that contains a low level of progestin locally may have the most minor effect on SHBG. On the other hand, the ring or contraceptive patch may have the highest impact on SHBG. Oral contraceptives fall to the middle of the spectrum, with progestin-only and low-dose ethinylestradiol options having less impact on SHBG levels compared to standard dose options. 

Low Testosterone in Women and Elevated SHBG

Women using birth control pills or other forms of hormonal birth control may be at higher risk for androgen deficiency. 

Women using birth control pills or other forms of hormonal birth control may be at higher risk for androgen deficiency.

Symptoms of low testosterone in women include:

• Low libido
• Decreased muscle mass
• Decreased bone density
• Fatigue
• Lack of motivation
• Dry skin and signs of aging
• Mental health issues

High Sex Hormone Binding Globulin Level Risks

SHBG levels may predict the risk for blood clots or thrombosis, which is one of the more severe side effects of birth control pills. Your doctor can order an SHBG blood test to assess your level and risk. 

In addition, as SHBG levels rise from hormonal contraceptives, they tend to remain chronically elevated and have long-term effects on testosterone levels and hormone balance. A study looked at SHBG levels after discontinuing the pill and found that SHBG remained elevated and never returned to a level comparable to a woman who never used the pill. 

To learn more about high SHBG, how to lower SHBG, and the impacts of low SHBG, read this article.

When Non-Hormonal Birth Control Options Should Be Considered

Ask your doctor or nurse practitioner about the ingredients in your birth control pill and if there may be a lower dose option with fewer side effects. You can also discuss non-hormonal birth control options and if there may be a better fit for you.

If you are at higher risk for blood clots or have significant symptoms while on the pill, you may want to consider alternatives. Non-hormonal options include the copper IUD, condoms, and fertility awareness method. 

Your functional medicine provider can check SHBG, testosterone, and other hormone levels to help guide the conversation. If you need an open minded and knowledgeable practitioner for this conversation, please reach out to our clinic. 

While the pill may be the best option for some, long-term side effects are important to consider when making your decision. 

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References

1. Raps, M., Helmerhorst, F., Fleischer, K., Thomassen, S., Rosendaal, F., Rosing, J., Ballieux, B., & VAN Vliet, H. (2012). Sex hormone-binding globulin as a marker for the thrombotic risk of hormonal contraceptives. Journal of thrombosis and haemostasis : JTH, 10(6), 992–997. 
2. Hugon-Rodin, J., Alhenc-Gelas, M., Hemker, H. C., Brailly-Tabard, S., Guiochon-Mantel, A., Plu-Bureau, G., & Scarabin, P. Y. (2017). Sex hormone-binding globulin and thrombin generation in women using hormonal contraception. Biomarkers : biochemical indicators of exposure, response, and susceptibility to chemicals, 22(1), 81–85. 

Panzer, C., Wise, S., Fantini, G., Kang, D., Munarriz, R., Guay, A., & Goldstein, I. (2006). Impact of oral contraceptives on sex hormone-binding globulin and androgen levels: a retrospective study in women with sexual dysfunction. The journal of sexual medicine, 3(1), 104–113. https://doi.org/10.1111/j.1743-6109.2005.00198.x