Low progesterone levels are on the increase. Many factors are involved such as:

Insulin Resistance

About 25-80% of the population today are affected by IR causing tiredness and weight gain particularly. In women it affects ovarian function, leading to anovulation causing progesterone levels. The reversal of IR is necessary for ovarian function to return to normal . Please read Polycystic Ovary Syndrome (PCOS) and Menstrual Cycle.

Endocrine Disruptors

There are well over 100 endocrine disruptors, most mimic estrogen in their action. Alarmingly this is now found in our food, air, water, skin care products, sunscreens, plastics and many more. This increases cellular division in humans and animals in hormonally receptive tissues. Although the jury is still out, there are now many studies proving their influence. Excessive estrogen suppresses progesterone.


Stress affects us all and has a negative effect on our health. Dr Hans Selye wrote the first definitive study on stress. He identified three progressive stages in the body's reaction to it:

  • alarm
  • resistance
  • exhaustion

Exhaustion affects our adrenal glands, immune system glands, the thymus and lymph. This has multiple effects throughout the body, leading to many of the modern degenerative diseases. The adrenals make over 70 hormones. Exhausted adrenals cannot cope with the demands made on them, so levels of some hormones drop. Low progesterone is an inevitable result. This is due in part to the rise in two hormones, cortisol and adrenaline. These two stress hormones suppress progesterone.

A Defective Luteal Phase (in women)

This is affecting more and more women each day, due partly to:

  • insulin resistance
  • endocrine disruptors
  • stress
  • oral contraceptives
  • HRT

After ovulation, when the corpus luteum is making progesterone, which it should make for 14 days, the level falls earlier than it should, causing spotting to occur a few days before the full period. This in turn leads to difficulties in falling pregnant and miscarriages. The low progesterone level can be raised using supplemental progesterone during the last 14 days of the cycle.

SAD (seasonal affective disorder)

Seasonal affective disorder (SAD) is caused by the long nights experienced in high latitudes. Normal treatment is to make the sufferer extend the daylight hours with artificial lighting. Researchers have found that long nights cause a drop in the level of progesterone in the blood.

People have lived for centuries in high latitudes without suffering from the condition. So why now is this causing problems? Some evidence supports a correlation between the incidence of the disorder and the rise in environmental estrogens. Progesterone is a powerful antagonist to estrogen.

Oral Contraceptives

All drug based oral contraceptives suppress ovulation. Only when a woman ovulates does the ovaries make progesterone. By suppressing ovulation the luteal phase surge in progesterone does not take place, so levels stay at those found in the follicular phase. The little progesterone present is made by the adrenals, brain and glial cells. If the adrenals are stressed the level drops even lower. All oral contraceptives cause insulin resistance, which also suppresses ovarian function.


Naturally low progesterone levels are common in Post Menopausal women. HRT is usually prescribed, however, they contain the same synthetic hormones as contraceptives, but in smaller doses. Synthetic estrogen suppresses progesterone. The progestin in HRT does not replace progesterone, it is synthetic. Post Menopausal women are still subjected to the same endocrine disruptors as everyone else, further increasing estrogen levels. HRT also causes insulin resistance, leading to a slower metabolism.

Large Carbohydrate Meals

Evidence suggests that progesterone levels drop after a large meal containing too many refined carbohydrates. Refined carbohydrates, in particular sugar and wheat, cause the blood sugar to drop too quickly. This causes adrenaline to rise causing sugar to be stored in cells in the body, particularly the liver.  This pours into the blood bringing the level up again. As the sugar drains out it is replaced by water, causing bloating and weight gain.

Progesterone cannot be transported into the nucleus of the cells if there is either no sugar in them or too much sugar, which means that any of the symptoms of progesterone deficiency become worse.

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