By: Aleena Ortiz (he/she/they). Reviewed by Dr. Jenny Wares (she/her), Associate Medical Director of Clinical Services.
If you’re transitioning with estrogen, you will notice subtle (and not-so-subtle!) changes in your body and emotions. These changes are often called “feminizing” changes, although trans and nonbinary people take E for all kinds of reasons—not necessarily because they want to pass as cisgender women. Some people use E by itself while other people use additional medications.
This article is about progesterone, another type of gender-affirming hormone therapy (GAHT, also called HRT or hormone replacement therapy). While not everyone wants or needs to add progesterone to their care plan, some people greatly benefit from this medication. This article will help you understand the science behind progesterone and how it can change your body.
How do estrogen and progesterone work together?
By itself, estrogen causes changes in hair growth, hair density, bone density, fat body distribution, skin oil composition, bottom function and shrinkage, as well as libido and sexuality changes. These changes often occur around 6-12 months, and level out after around 1 or 2 years. Again, these changes are considered “feminizing” by some people, because they create a look that is more aligned with our culture’s idea of femininity.
By adding progesterone (P4), it is possible that such changes occur more rapidly. P4 can greatly affect your mental health while you’re taking GAHT, leading to a more rounded and stable experience. Studies have found that transitioning with progesterone leads to greater mental wellness for transfeminine folks.
While the effects of estradiol have been studied at length, less research has been done on the benefits and drawbacks of progesterone. If you want to know what to expect during your transition and how progesterone may affect your individual body, talk to your medical provider.
Where does progesterone come from?
Progesterone is related to many processes, such as the sleep cycle, mood, and long-term bone density. Like other hormones, it can have a profound effect on every one of your body’s systems. Everyone’s body naturally produces progesterone in different amounts.
Progesterone is most evidently related to internal rhythms like menstruation and pregnancy. The naturally-occurring hormone prepares the endometrium for pregnancy by thickening or thinning the uterine wall, allowing unfertilized eggs to fall during menstruation and fertilized eggs to stick during pregnancy. If you have ovaries, your body will produce progesterone unless you’re taking medication to suppress your menstrual cycle. For example, progesterone pills are a common method for controlling bleeding, cramps, and preventing pregnancy.
People who have testes also produce progesterone naturally. (If you’ve had an orchiectomy, your body will continue to make small amounts of progesterone with your adrenal glands.)
What happens when you add progesterone?
Recent studies have suggested the benefits of adding progesterone to estrogen for trans women, nonbinary people, and gender non-conforming folks. Because research on the long- and short-term effects of P4 on transfeminine folks is currently limited, it’s important to work with your medical provider. The effects of progesterone are supported, but a lot of the studies about its effects on transfeminine folks are hypothesized with scientific evidence based on cisgender people.
Since progesterone is a hormone, it will affect many aspects of your body and mind. This medication is not for everyone, but many transfeminine people benefit from using it. The physical effects of adding progesterone to E include:
- Fuller breast and nipple development
- Stabilization of sleep cycles
- Mood and mental health stability
- Prevention of long-term bone density problems
- Prevention of long-term cardiovascular health problems
- Anti-androgenizing effects (blockage of masculinizing hormones), which affects sexual function and bottom shrinkage
Depending on your individual body, the physical changes caused by progesterone may be subtle or they may be dramatic. This is especially true for breast growth or bottom changes. While hormones are powerful and change your body over a long period of time, they may not give the full effect that some people want. Some transfemmes will still want to pursue top or bottom surgery to achieve the body changes they want, in addition to GAHT. Talk to your medical provider about your gender transition goals to understand what progesterone and/or E can do.
What are the risks of taking progesterone for my transition?
So far, progesterone has not shown any adverse health effects, either in studies or community experiences shared by trans people. Still, it is very important to work closely with your doctor or Care Team when taking GAHT. Getting regular lab work will help your medical provider monitor any changes to your bone density, cardiovascular health, hormone levels, and other health markers. Some people notice that taking progesterone disrupts their sleep patterns by affecting the circadian rhythm. Others have negative mood effects. Everyone’s body is different, so in these cases, it is best to stay in touch with your gender-affirming health care provider and let them know if you feel that progesterone is affecting your mental health or wellness.Who should take progesterone?
Progesterone is just one possible medication for people who want to transition with GAHT. It can be used by itself, with estrogen, or with T-blockers like spironolactone, finasteride, and dutasteride. Talk to your gender-affirming health care provider about adding progesterone, adjusting your E dosage, and the possible benefits and drawbacks of changing your medications. Whatever your transition goals, your care provider can support you.
Since the effects of P4 are still under research for transfeminine folks, it is unclear how much progesterone affects the gender transition process. However, given its known effects and functions, some people find that this hormone helps them feel more at home in their bodies than estrogen alone.
Whatever your transition goals are, remember that you can take it slow. With expert medical support, you can find the combination of medications that is best for your body and your goals. Not everyone’s body will respond to GAHT the same way, but the possibilities of living a life full of transitional experiences is endless.
Aleena Ortiz (he/she/they) is an independent world traveler, freelance writer, and contract book reviewer at Foreword Magazine. They obtained a Bachelor of Arts in Religion with a focus on Buddhism, Daoism, and Shintō at Reed College in May 2021. Eager to explore fictive worlds with respect to cultural sensitivity and the complexities of human emotion, he has published over 1 million words online over the last decade. Aleena strives to create space for nuanced understanding of historically underrepresented groups through her analyses of media and in fiction writing.
As the largest provider of gender-affirming care for the trans and nonbinary community, Plume is committed to providing information about many types of information, including questions about hormones like estrogen and testosterone, gender transitioning tips and experiences, and guidance on social transition and self care.
While we strive to include a diverse range of voices and expertise, not everything will be for every person. Each individual’s experience is unique, and the information Plume provides is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
Always first seek the advice of your primary and/or specialist physician, the Plume Care Team, or other qualified health provider with any questions you may have regarding a medical condition, your mental health and emotional needs, or your health care needs regarding gender-affirming hormone therapy. If you are experiencing an emergency, including a mental health crisis, call 911 or reach out to Trans LifeLine.
