Safety and Adverse effects of Natural Progesterone

progesterone-prometrium-100mg-100ctSafety and Adverse effects of Natural Progesterone

I received this email from a patient:

Hello Dr Dach,

I mentioned to my mom this evening that I would start to take progesterone pills next month for a portion of my cycle. She said that a few years ago, she used a progesterone cream. She said she couldn’t remember the reason why her doctor put her on a cream instead of a pill so she wanted me to ask about the health risks that go along with taking a progesterone pill.

I didn’t think to ask Dr. Dach when I spoke with him today about the side effects of using progesterone (pill or cream). Are there any side effects that I should be concerned about or aware of? Is there any difference in health risks between the progesterone pill or cream?

Thank you all for the time that you spend with me answering questions and planning my treatment! I really appreciate it!

Sincerely, Nancy

My Reply to Nancy:

Hi Nancy,

Progesterone is the natural hormone made by the ovary after ovulation, so it is very safe with no adverse effects.  Excess dosage however, can cause drowsiness, which is helpful for treating insomnia if taken before bedtime to get a good night’s sleep.

For the cycling female, the usual dosage is 100 mg capsule twice a day with food for days 12-26 of the cycle.  If the morning progesterone dosage causes drowsiness, then this is omitted and instead both capsules are taken at night before sleep.

Sometimes, a patient mistakenly confuses Progesterone with the Progestins.  Progestins are synthetic hormones which are chemically altered forms of Progesterone.  The Progestins are known to cause cancer and heart disease, and have other adverse effects which are not shared by natural progesterone.  For this reason, we do not prescribe Progestins in my office.  We use the safer natural progesterone.

Article on the origin of progesterone:

Russell Marker and the Origins of Bioidentical Hormones

Article by Dr. Mercola on Progesterone

Articles with Related Interest:


  1. Phyllis Bronson,Ph.D. January 16, 2014 at 10:31 AM

    The interface of the neurosteroid, progesterone, and GABA, an inhibitory neurotransmitter and amino acid -both- is very significant in understanding the mechanism by which GABA works, particularly in women. We have helped many women get off benzodiazepine drugs by learning this.
    In the presence of the progesterone metabolite allopregnanolone, the subunit on the GABA-AR is activated and downregulated- meaning one becomes calmer. if there is not sufficient alloprgnanolone, then GABA can become an excitatory (stimulant) molecule instead of calming. GABA is fantastic for calmness but because of these complex mechanisms, little is obvious about its uptake as it does not cross the BB in the usual sequences.

  2. Larry Frieders January 16, 2014 at 1:53 PM

    A large part of the ‘problem’ is the language we use. Both progesterone USP and medroxyprogesterone are progestins. I have a strong feeling that he definitions were intentionally made confusing so that the drug versions could be passed off as a kind of progesterone. Insidious?

    regards from Larry Frieders

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