Why Might I Need To Take Cyclic Progesterone Therapy?
Progesterone is one of two important women’s hormones; estrogen is the one we usually hear about. Progesterone can be prescribed for daily use (for menopausal women, or to treat perimenopausal heavy flow), or it can be given ‘cyclically’. Cyclic means progesterone is given for the last 14 days of the menstrual cycle, to mimic the normal high-progesterone time of the cycle, called the luteal phase.
Progesterone levels are low when:
- menstrual cycle length is irregular
- cycles are long or skipped, or
- when egg release (ovulation) is absent (that occurs despite ‘regular’ meaning normal-length and predictable menstrual cycles).
Your doctor may prescribe progesterone or a synthetic called medroxyprogesterone (MPA), to control heavy flow, prevent irregular periods, acne, unwanted hair, or treat low bone density in premenopausal women. Or progesterone may be prescribed for perimenopausal sore breasts, sleep problems, heavy flow or night sweats.
Cyclic progesterone therapy (not MPA) also may help women with short luteal phase achieve pregnancy (but more about that in the CeMCOR article “When should I have sex to get pregnant?”.
What Medications Can I Choose?
Oral micronized progesterone (Prometrium®, generic, or the same hormone “compounded” in oil by a pharmacist) is identical to your own hormone (or bio-identical). Because it may cause sleepiness, only take this medication on your way to bed. Three 100 mg capsules is the dose that keeps progesterone levels in the normal luteal phase range for 24 hours.
Medroxyprogesterone (MPA) is synthetic, a progestin that has been used for over 60 years. As a pill it does not provide contraception like Depo-MPA, and doesn’t have the same side effects while on it or difficulties when stopping it.
MPA is given cyclically in premenopausal women like progesterone. Its main advantage is that it is in expensive. It should only be used if you cannot afford the cost of progesterone. It is stronger than progesterone so the dose that creates a progesterone-like effect is 10 mg. a day. Avoid use of cyclic MPA if you have personal risks for, or a family history of, breast cancer. Also avoid MPA in perimenopause when your own estrogen levels are likely to be higher than normal.
When Do I Take It?
The first day of menstruation is called “day 1.” If you get a period regularly and your cycles are usually 27-30+ days long, start cyclic progesterone on the 14th day after flow began and take it for 14 days or until cycle day 27. If your cycles are regular but shorter (for example, if your period starts every 21–26 days), then start cyclic progesterone on cycle day 12 and continue it for 14 days or until cycle day 25.
FIGURE 1
Always finish the full 14 days of progesterone, even If your period starts before you have finished the cycle of progesterone.
Start the next cycle of progesterone 14 days after the day that flow began (see Figure 2). This is key to cyclic progesterone helping you, so I’ll write it again: Even if your period starts while you are still taking progesterone, always take it for the full 14 days. If this early flow persists, or you are in perimenopause, then you either need daily progesterone for three months or to increase the dose of cyclic progesterone therapy to 400 mg. The early flow is a sign that your body is making high levels of estrogen that are over-stimulating the endometrium (uterus lining) causing early or heavy bleeding.
If you have not started to flow within 2 weeks of taking cyclic progesterone, it means your own estrogen levels are low. After 14-days “off,” start the next progesterone cycle. As soon as your flow returns, then start taking progesterone again, 14 days after the start of your flow, as shown in Figure 1.
FIGURE 2
Are There Any Side Effects?
There are no serious negative effects from progesterone therapy. Improved sleep could be considered a “side effect” of progesterone! Progesterone does not cause blood clots, migraine headaches or increase the risk for breast cancer. However, if you have migraine with aura, you could take progesterone daily, but not cyclically—change, such as stopping it, may trigger a migraine.
Progesterone in a dose of 300 mg for 14 days will effectively prevent endometrial cancer. Note that pharmacy references say that either progesterone or MPA causes everything shown on “the Pill” (combined hormonal contraceptives) which contain 4 times normal estrogen doses plus synthetic progestins. Progesterone is now in sunflower seed oil so peanut allergy is no longer a risk.
You may notice some changes in your breasts, feelings of warmth and other evidences of normal progesterone action. If you get moody, feel bloated and have very sore breasts it means progesterone is temporarily stimulating your body to make higher estrogen levels. This improves after one cycle.
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