Written on January 24, 2024 by Jillian Foglesong Stabile, MD, FAAFP. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Birth control, also known as contraception, is a very commonly prescribed medication. Birth control is available in many forms, both hormonal and non-hormonal. Any time you consider a medication, even a common one, you should consider the risks, benefits, and possible side effects.
You may be wondering about some of the potential side effects of birth control, such as weight gain, irregular periods, and mood changes. You may even be wondering, can birth control cause hair loss? The short answer is yes, but it’s complicated.
Birth control can be divided into two general types: hormonal and non-hormonal. Non-hormonal forms of birth control are unlikely to affect hair growth or loss. Hormonal forms of birth control are more likely to have an effect.
Hormonal birth control can be found in many forms, including :
Hormonal birth control works by suppressing ovulation, among other effects. Some prevent the fertilized egg from implanting in the uterus, and others cause the mucus in the cervix to become thick, preventing sperm from getting through to fertilize the egg.The hormones included in birth control are generally either a combination of estrogen and progesterone or progesterone alone.
Oral contraceptive pills are available in both combination forms and progestin-only forms. The contraceptive injection and implant are both progestin-only. The skin patch and vaginal ring are both available as combination medications.
As hair grows, it goes through four stages :
The condition of alopecia, hair loss or thinning, occurs when the cycles are shortened. The type of hair loss that is mediated by hormones is usually caused by an excessive amount of androgenic hormones.
Some women and people assigned female at birth (AFAB) are more prone to hair loss associated with fluctuations in hormones. Hormonal changes may be related to pregnancy, menopause, or medication. Rarely, hormone changes could be related to other conditions, such as an ovarian tumor or polycystic ovarian syndrome (PCOS). [3,4]
Hormone changes, such as lower levels of estrogen and progesterone compared with androgenic hormone levels, may cause hair loss. This is one of the reasons why menopause and PCOS are associated with hair loss. They both cause an imbalance of hormones between estrogenic and androgenic effects. Androgenic hormones cause the hair follicles to shrink and cut off the supply of blood and nutrients. This leads to shortened anagen phases and increased hair loss.
Some forms of hormonal birth control contain higher levels of androgenic hormones than others. The progestin in hormonal contraceptives is responsible for androgenic activity and is the component of contraceptives associated with hair loss. As newer generations of progestins have been developed, the androgenic effects of the hormones have decreased.
There are four categories of progestins used in contraceptives, and they vary in androgenic effects. :
Medroxyprogesterone, the progestin present in the “depo shot,” has studies showing mixed results when it comes to androgenic effects. Some studies have shown no effects on hair loss, while others have shown androgenic effects, including hair loss.
Estrogen in combined birth control methods can help offset the androgenic effects of the progestins by extending the anagen phase of the hair cycle. This is one of the reasons that pregnancy, a condition that increases estrogen levels in the body, usually causes increased hair growth and thicker hair.
If progestins have been shown to have some negative effects, such as hair loss, why wouldn’t birth control pills be made of just estrogen? The answer is that if estrogen is not balanced by progesterone, serious conditions can result. Estrogen causes the cells that line the uterus, the endometrium, to grow, but progesterone stabilizes the endometrium.
If the two hormones are not balanced, a condition called endometrial hyperplasia (excessive growth of the uterine lining) can occur. This condition can lead to endometrial polyps, endometriosis (endometrial cells growing outside of the uterus), adenomyosis (endometrial cells invading the uterine muscles), and endometrial cancer. For this reason, estrogen-containing birth control is carefully balanced with progesterone.
While some forms of birth control can cause hair loss due to the androgenic effects mentioned previously, hair loss can also occur when birth control is stopped. This is believed to be due to the decrease in estrogen that occurs when you stop birth control. The withdrawal of estrogen leads to an increased number of hairs going into the telogen stage of the hair cycle. This can lead to a condition called telogen effluvium (a larger number of hairs in the resting stage that will then go into the shedding stage) This is also the reason women and people AFAB tend to lose more hair than normal when they are postpartum.
At Everlywell, we strive to give you accurate results in a convenient fashion. If you're considering stopping or starting birth control, you may be curious about your hormone levels and fertility. Everlywell's at-home women’s fertility test is a discreet, seamless way to take control of your health and learn more about your body. Our CLIA-certified labs and experienced clinical team deliver information that you can trust. You can also schedule a women’s health virtual care visit with one of our licensed healthcare professionals. Take control of your reproductive health with Everlywell.
Jillian Foglesong Stabile, MD, FAAFP is a board-certified Family Physician. Since completing her residency training in 2010, she’s been practicing full-scope family medicine in a rural setting. Dr. Foglesong Stabile’s practice includes caring for patients of all ages for preventative care as well as chronic disease management. She also provides prenatal care and delivers babies. Dr. Foglesong Stabile completed a teaching fellowship in 2020 and teaches the family medicine clerkship for one of her local medical schools. Dr. Foglesong Stabile’s favorite thing about family medicine is the variety of patients she sees in her clinical practice.