Yes, natural progesterone can be used to suppress endometriosis. Estrogen stimulates endometriosis and progesterone inhibits it. Approximately 20 years ago it was common to treat severe endometriosis with medroxyprogesterone, a cousin of natural progesterone.
Using progesterone for suppression requires high doses—such as oral micronized progesterone, Prometrium®, 300 mg by mouth at bedtime and 300 mg vaginally (held in with a tampon) daily in the mornings. Because anything suppressing estrogen levels will cause bone loss, high doses of calcium and vitamin D, healthy exercise and stable weight are needed to prevent bone loss (See The ABCs of Osteoporosis Prevention for Premenopausal Women [1]). Suppression should continue for six months before gradually decreasing to once a day and then changing to cyclic progesterone therapy [2].
A high dose of progesterone is needed for ovarian and endometriomal suppression. It must suppress hypothalamic gonadotrophin releasing hormone (GnRH) production and therefore cause the ovaries to make less estrogen. Progesterone treatment also decreases the activity of estrogen receptors (and therefore slows estrogen action in tissues such as the endometrium).
I recommend a daily dose of 300 mg of Prometrium® at bedtime and 300 mg vaginally in the morning. (Progesterone by mouth causes too much drowsiness to be taken during the day.) If this dose is not sufficient to stop flow, control cramps and endometriosis-related abdominal pain, the dose must be increased. The idea is to suppress flow for about six months. Keeping a record using the daily Menstrual Cycle Diary [3]® is a good idea.
After six months without flow and pain, I would recommend decreasing the Prometrium dose to 300 mg at bedtime daily and see if she continues without symptoms. If she remains pain free, she could then stop the treatment for two weeks and begin again in two weeks, always taking Prometrium® 300 mg at bedtime for two weeks at a time. Once flow starts, progesterone should be taken cyclically days 14 through 27 of her own cycle for at least a further six months.
If Prometrium® is too expensive to afford for both morning and night, its cousin, medroxyprogesterone 10 mg/d could be taken in the morning instead. Medroxyprogesterone is less costly than Prometrium®. If medroxyprogesterone were taken instead of Prometrium® the dose is 10 mg in the morning and evening. As with progesterone, this suppressive dose should be continued for six months, then once a day for another month or two and finally cyclically for a further six months.
Note that any medicine that suppresses periods and estrogen levels will cause bone loss (much like DepoProvera® does). For this reason it is very important to do the following things to prevent bone loss.
- Take elemental calcium in a total daily dose of 2000 mg/d. Calcium is not stored so it is best absorbed when spread across the day with meals and at bedtime. Calcium can be obtained from foods (a glass of milk [250 ml] of milk or a fortified beverage provides 300 mg of calcium) and supplements taking a maximum dose of 500 mg at a time.
- I would recommend 800-1200 IU of vitamin D a day to assist in the absorption of calcium. It can be taken all at once.
- Continue to be physically active with at least a half an hour a day of walking.
- Don’t lose weight.
I think that using natural progesterone to suppress endometrial growth is safer than other therapies. Why? First, natural progesterone stimulates new bone formation. If bone loss can be controlled by higher doses of calcium and vitamin D, progesterone will be less negative for bones than other suppressive therapies. Second, natural progesterone suppresses the ovaries without causing hot flushes like GnRH agonist therapy does. Third, progesterone has no side effects such as hair growth or acne like danazol does. Fourth, this treatment is flexible and can be adjusted based on a women’s experiences. It is under her control and is not an injection that is temporarily irreversible.
Thank you for your question. I hope this is helpful for you.
