While you read this article, your body is busy at work: Chemicals are being secreted from glands, organs, and tissues, sending messages that direct your body to react in certain ways. These chemicals, called hormones, regulate everything from growth and reproduction to digestion and mental health.
Progesterone and progestin are two hormones that you may have heard of. They have similar-sounding names, and it can be tricky to tell the difference between the two. However, the differences are important to know about. Read on to learn more about these important hormones and how they can affect our bodies.
Language matters
In this article, we use “male and female” to refer to someone’s sex as determined by their chromosomes, and “men and women” when referring to their gender (unless quoting from sources using nonspecific language).
Sex is determined by chromosomes, and gender is a social construct that can vary between time periods and cultures. Both of these aspects are acknowledged to exist on a spectrum both historically and by modern scientific consensus.
Progesterone-based hormone treatments are used by trans and cis women alike.
In short, yes and no: Progesterone is a naturally occurring steroid hormone made in varying amounts by male, female, and intersex bodies. Progestin is a synthetic chemical that mimics the effects of progesterone on the body.
So-called “natural” or “bioidentical” progesterone medications also exist. This name is somewhat inaccurate, though: Progesterone medications are synthesized from a plant chemical called diosgenin — which is found in wild yam.
In addition to creating progesterone for use in birth control, diosgenin is also commonly used to synthesize other steroid hormones that are used in medications, including cortisone, pregnenolone, and progesterone.
Female and some intersex bodies naturally produce surges of progesterone after ovulation. This drives the second half of the menstrual cycle, preparing the body to potentially grow an embryo from a fertilized egg.
If an egg is fertilized, the body will release even more progesterone to support the fetus during pregnancy. During pregnancy, progesterone ensures the womb grows and prevents premature contractions (which can lead to miscarriage).
In male and other intersex bodies, progesterone is produced in lower quantities. In these bodies progesterone plays an important role in sperm development, maintaining testosterone levels, and other body functions.
When a person’s progesterone levels are high, they may experience:
When levels are too low, they may lead to irregular periods, anxiety, headaches, and depression. People with low progesterone levels may have difficulty getting pregnant and keeping a pregnancy. What a normal progesterone level is for a person depends on their age, sex, gender, and individual health status.
Two types of progesterone medications emerged during the early development of birth control pills in the 1950s and 1960s. This includes
Progestins work similarly to progesterone in the body, but each type of synthetic progestin has its own effects on the body and may be used to treat different conditions.
In addition to its key use in progestin-only birth control “mini-pills” and combination estrogen-progestin birth control pills, the common uses for progestins are to treat irregular menstrual periods, including amenorrhea and abnormal bleeding. Some others include:
- treating certain cancers that react to hormones
- providing gender-affirming therapy
- alleviating symptoms of menopause
- slowing bone loss
- part of fertility treatments
Progestin medications may come in pill, gel, cream, injection, transdermal patch, or suppository form, depending on its use.
For some people, progestin may be the best available medication to address their needs. In other cases, people may choose between progestin and progesterone medications.
Some progesterone medications, such as topical creams, can be bought over the counter to address some of the symptoms of menopause. The side effects of both progestin and progesterone are similar. For both types of medications, it’s important to follow dosage directions to avoid potentially serious adverse side effects.
Compare the side effects of progesterone medications and progestin medications:
| Progestin | Progesterone |
| increased risk of breast cancer | increased |
| changes in menstrual bleeding | depression |
| breast tenderness | breast tenderness |
| headaches | headaches |
| nausea | skin reactions |
| increased risk of blood clotting |
Don’t forget!
While these treatments can be lifesaving, they can also have dangerous side effects. Always follow your doctor’s dosing instructions for any hormonal treatment carefully and discuss any new symptoms with them as soon as possible.
The majority of progesterone-like medications on the market today are made of progestin. However, a growing number of progestin medications are on the market, including a few that have been approved by the FDA.
Progestin vs. progesterone: uses in birth control
Progestin is more commonly used than progesterone in various forms of birth control, including the hormonal IUD, pill, and injection.
In these uses, progestin thickens the mucus of the cervix so that sperm can’t enter to fertilize an egg. It also thickens the lining of the uterus, controlling bleeding, and can sometimes stop ovulation.
Some progestins are mixed with estrogens to produce combined birth control pills that prevent pregnancy by preventing ovulation. These pills carry a risk of blood clots for people over age 35, especially if they smoke.
Progestin vs. progesterone: uses in menstrual cycle treatment
One
Progestin is also used to treat polycystic ovarian syndrome (PCOS). However, due to the wide availability of bioidentical progesterones on the market, many people use over-the-counter progesterone creams to help regulate irregular periods.
Progestin vs. progesterone: uses in fertility treatment
Bioidentical progesterones are now popularly used in fertility treatments. Many products are now on the market, from creams to pills. However, little research exists on the efficacy of many of these treatments.
Progestin vs. progesterone: uses in menopause symptom treatment
In treating menopause symptoms, including bone loss, progestin is a commonly prescribed medication. However, over-the-counter progesterone creams and supplements are growing in popularity.
Research suggests several risks of taking progestins for menopause symptoms, including the risk of serious adverse side effects — such as blood clots and heart problems — in some older people.
Progestin vs. progesterone: uses in gender-affirming care
While it has been overlooked in the past, experts now believe progesterone can play an important role in gender-affirming therapy when combined with estrogen for people looking to increase their body’s feminization.
- diminish testosterone production
- increase bone mass
- improve sleep
- benefit their heart health
Is progestin cream as effective as progesterone cream?
Progesterone cream is typically not made of progestin.
Instead, creams commonly contain bioidentical progesterone to increase fertility, regulate the menstrual cycle, and alleviate symptoms of menopause. Some prescription progesterone gels also exist to treat infertility.
Progestin and progesterone are two kinds of steroid medications used in care for menstrual issues, menopause symptoms, fertility issues, and gender-affirming therapies.
While they have similar names, progestin refers to a synthesized chemical that acts similarly to natural progesterone in the body. Progesterone medications aren’t made from human chemicals but from plants. They also act similarly to progesterone in the body.
The kind of progesterone medication you might use depends on your needs and medical history. Talk with your doctor to learn more about your options.