What Causes Low Progesterone Levels?

Progesterone is a natural progestogen secreted by the ovarian corpus luteum, also known as “luteal hormone.” Progesterone plays a vital role in women’s health—particularly in fertility and embryonic development. During conception, progesterone stimulates uterine changes, enhances blood flow to reproductive system vessels and tissues, and supports embryo development within the estrogen-primed endometrium—making it essential for maintaining pregnancy. So, what causes low progesterone levels? Below are the main contributing factors.

Causes of Low Progesterone

1. Uterine Abnormalities

During conception, progesterone stimulates uterine changes and promotes embryonic development by increasing blood flow to the reproductive system’s vasculature and tissues—specifically within the estrogen-primed endometrium. Prior uterine trauma—including threatened miscarriage, ectopic pregnancy, preterm birth, amenorrhea, or infertility—can directly result in low progesterone levels.

2. Endocrine Imbalance

In early embryonic development, three key hormones—estrogen, progesterone, and human chorionic gonadotropin (hCG)—are required. Endocrine imbalance can therefore lead to insufficient progesterone production. Severe dysfunction of the adrenal glands or thyroid gland may induce pathological conditions that impair ovarian function, hinder conception, disrupt ovulation, and consequently reduce progesterone levels.

3. Luteal Phase Deficiency

If the corpus luteum functions inadequately—or fails to develop properly—the resulting decline in progesterone secretion leads to lower-than-normal progesterone levels compared with those in healthy women.

Additional Information: Dietary Sources to Support Progesterone Levels

1. Soy Products

Soy contains numerous nutrients. Vitamin B6 in soy helps stabilize mood, improve sleep quality, and alleviate abdominal discomfort. Soy is also rich in essential fatty acids, which contribute to skin health by improving roughness. Most importantly, soy contains relatively high levels of phyto-progesterone precursors, aiding hormonal balance and helping address low progesterone—making it an optimal dietary choice for supplementation.

2. Foods Rich in Vitamin E

Vitamin E promotes sex hormone secretion, enhances ovarian function, increases follicle count, enlarges luteal cells, and potentiates progesterone activity. Women with low progesterone levels may benefit from consuming vitamin E–rich foods. Such foods include corn, peanuts, sesame seeds, soybeans, sunflower seeds, brown rice, dairy products, eggs, and fish.

Low progesterone during pregnancy may trigger symptoms of threatened miscarriage. It poses significant risks to maternal health and requires timely intervention and supplementation.