You’ve written about progesterone and weight gain before. What about choosing the type of progesterone in your combined oral birth control? Do some progesterones have more desirable effects, like improving acne (e.g. Yaz)?
—Anonymous
This question makes my endocrinologist heart so happy! The short answer is yes, the type of progestin in a combined birth control pill can have impacts on that pill’s side-effect profile. But how and why are worth understanding.
First, a quick review. Combination birth control pills typically contain ethinyl estradiol, but in different amounts — modern pills vary from just 10 micrograms of estradiol to as much as 35 mcg. They also contain a synthetic progestin, of which there are several, in various doses.
Estrogen, progesterone, and testosterone are all part of a group of hormones called steroid hormones. Both the hormones and their receptors are somewhat similar. So progesterone or a synthetic progesterone-like molecule can bind to the testosterone receptor and act like testosterone. Some progestins in birth control pills are more or less likely to do this. Both the affinity of the progestin for the testosterone receptor and the amount of estradiol in a pill will change how androgenic a pill is — that is, how much that pill will cause testosterone-like side effects.
In general, progestins that were developed earlier had higher androgenic effects than those developed later. The most androgenic progestins are norgestrel and levonorgestrel. Norethindrone is in the middle, and desogestrel and norgestimate are the least androgenic progestins.
Some of the most recently developed progestins, like drospirenone — the progesterone in Yasmin and Yaz — have anti-androgenic effects. This means that they sit in the testosterone receptor but do not act like testosterone, and they block testosterone from acting on the receptor too. This should make pills that contain anti-androgenic progestins especially good at treating androgenic symptoms like acne, body hair growth, and scalp hair loss. However, the amount of progestin and the amount of estrogen will also affect how effective a given birth control pill is at treating symptoms like acne and minimizing side effects.
When I am choosing a birth control pill for a patient, I consider what birth control pills they have taken in the past, the indication for which we are starting the pill (i.e. contraception, PCOS, acne, perimenopause), and the patient’s age (typically I prefer lower-estrogen pills when women are in their 40s). I also recommend that my patients try a pill for three months, and then we can reassess and switch pills — or contraceptive methods altogether — if needed.
The upshot: Some progestins are more androgenic than others, and some are even anti-androgenic. This is one factor I consider when helping a patient choose a birth control pill.
Community Guidelines
Log in
Is there data to back up the idea that different progesterones have different side effect profile or is it just based on their biochemical profile and assumptions about how that will impact patients?