PART 1

Connection Between Oral Contraceptives and Elevated SHBG

Birth control pills are a popular and effective form of birth control, but they may cause unintended side effects, including long-term changes in sex hormone binding globulin. 

In a previous series Causes and Solutions for Elevated SHBG and TBG Levels, I dove into sex hormone binding globulin, known as SHBG, and how this critical protein helps regulate our hormone levels. When SHBG is high or low, women may experience symptoms of hormone imbalance. 

In this month’s series, I will take a closer look at the impact oral contraceptives and other forms of birth control on SHBG and what that means for you as you consider your options. 

Today I will cover the following:

• The basics of contraceptive pills
• Birth control pill effectiveness
• Birth control side effects

Then, in part 2, I will cover more about the link between contraceptive pills and testosterone in women. It’s a rarely discussed, yet important topic in women’s health. You’ll want to consider this information when making the choice about what contraceptive is best for you. Let’s get started! 

Birth Control Pills 101

In 1960, the FDA approved the first oral contraceptive, which quickly became known as “the pill.” The pill gave women new freedom in reproductive choice and became an alternative to other, less effective options. 

Today, there are many pill options available. Early oral contraceptives were a combination of synthetic estrogen (such as ethinylestradiol) and synthetic progesterone (called progestin), and this combination remains available. Newer, low-dose pills are progestin-only. Today 25% of women in the U.S. aged 15 to 49 use hormonal contraceptives, including the pill, IUDs, and implants.

The birth control pill works by suppressing ovulation. If you don’t ovulate, you can’t get pregnant. The bleeding you experience on the pill isn’t a true menstrual period. Birth control pills are a popular and effective form of birth control, but they may cause unintended side effects, including long-term changes in sex hormone binding globulin.

Birth control pills are a popular and effective form of birth control, but they may cause unintended side effects, including long-term changes in sex hormone binding globulin.

Birth Control Pills – Pros and Cons

Let’s take a closer look at some of the benefits and drawbacks of oral contraceptives. 

Pro: Birth Control Pill Effectiveness

The main benefit of oral contraceptives is their effectiveness in preventing pregnancy. When used correctly, the pill is around 99% effective. With typical use, it’s about 92% effective. 

To be effective, the birth control pill must be taken daily around the same time each day. Skipping pills or combining pills with certain medications (like antibiotics) may reduce their effectiveness. 

Con: Birth Control Pill Side Effects

Since the birth control pill stops ovulation, it also suppresses your body’s natural production or hormones including progesterone, estrogen, and testosterone, while increasing SHBG. This may lead to symptoms of low hormone levels. 

Since the birth control pill stops ovulation, it also suppresses your body’s natural production or hormones including progesterone, estrogen, and testosterone, while increasing SHBG. This may lead to symptoms of low hormone levels.

Side effects of oral contraceptives may include:

• Decreased arousal and desire
• Decreased vaginal lubrication
• Increased pain with sex
• Decreased frequency and enjoyment of sex
• Weight gain
• Mood changes
• Headaches or migraines 
• Blood clots 

Blood Clots and Thrombosis

One of birth control’s most serious side effects is thrombosis, or blood clots. Interestingly, elevated SHBG may be a marker for blood clot risk. 

Elevated SHBG also contributes to women’s low testosterone (and low estrogen) levels. Birth control pills may be the largest contributor to increased SHBG and low testosterone in women. And unfortunately, levels persist, even after discontinuing the pill, which may impact hormone levels, fertility, bone density, muscle mass, and more. 

Stay tuned for Part 2 of this article, where I’ll get into the specifics of birth control, SHBG, and testosterone. 

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References

1. https://www.cdc.gov/nchs/fastats/contraceptive.htm 
2. 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. 

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