Progesterone: Functions and Side Effects

Oct 28, 2021 Source: Cainiu Health

Dr. Chen Bin

Introduction

Functions: 1. Prevention of miscarriage—supplemental progesterone during pregnancy helps maintain the decidual reaction in women. 2. Promotion of lactation—progesterone, acting synergistically with estrogen, stimulates breast development. 3. Inhibition of uterine contractions—progesterone alters the permeability of uterine myocyte membranes. Adverse effects: Nausea, dizziness, headache, fatigue, etc.

Progesterone, a naturally occurring progestogen hormone, plays an important regulatory role in the female endocrine system and is commonly used to treat menstrual disorders such as irregular menstruation and amenorrhea. However, like all medications, progesterone may cause certain side effects. Some women may experience dizziness, weight gain, or other adverse reactions after taking it. So, what are the therapeutic effects and potential side effects of progesterone? Below, we provide a detailed explanation.

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Therapeutic Effects of Progesterone

1. Prevention of Miscarriage

During pregnancy, supplemental progesterone helps maintain the decidual reaction—the transformation of endometrial stromal cells into specialized decidual cells rich in glycogen granules, which nourish the blastocyst. Thus, adequate progesterone supplementation during pregnancy effectively reduces the risk of miscarriage.

2. Promotion of Lactation

In synergy with estrogen, progesterone promotes mammary gland development and facilitates postpartum lactation, preparing the body for breastfeeding. Additionally, progesterone is indicated for conditions associated with luteal phase deficiency, including irregular vaginal bleeding, shortened menstrual cycles, and embryonic growth arrest.

3. Inhibition of Uterine Contractions

Progesterone alters the membrane permeability of uterine myocytes, thereby reducing their excitability. It also decreases the sensitivity of uterine smooth muscle to oxytocin. As a result, under the influence of progesterone, uterine contractions are significantly suppressed during pregnancy—offering substantial protection to the developing embryo.

Side Effects of Progesterone

1. As a progestogen, progesterone is clinically used to manage dysmenorrhea, amenorrhea, premenstrual syndrome (PMS), habitual abortion, and threatened miscarriage. However, it carries multiple potential side effects. Common adverse reactions include breakthrough bleeding, spotting, weight gain or loss, changes in the squamocolumnar junction of the cervix, alterations in cervical mucus characteristics, breast tenderness, nausea, dizziness, headache, and fatigue.

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2. Less common but possible side effects include fever, insomnia, allergic reactions—with or without pruritus—as well as melasma, chloasma, and obstructive jaundice. Therefore, patients should always take progesterone strictly under medical supervision and avoid self-administering excessive doses. Additionally, maintaining emotional well-being, adhering to a light diet, avoiding late-night activities, and undergoing regular gynecological examinations are strongly recommended for optimal health management and prevention.

The above outlines the primary therapeutic effects and potential side effects of progesterone. We hope this information proves helpful to you.

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What progesterone and estradiol levels indicate ovulation?

Under normal circumstances, progesterone levels rise to >3 ng/mL after ovulation, while estradiol peaks at 200–300 pg/mL just before ovulation, then dips briefly and rises again post-ovulation. Adjust your daily routine according to these hormonal fluctuations: include soy products and fresh fruits and vegetables in all three daily meals, and maintain regular sleep–wake cycles—avoid staying up late. During the preconception period, engage in moderate outdoor physical activity.