Progesterone is a steroid hormone that is mainly produced by the corpus luteum in the ovaries during the second half of the menstrual cycle. Its principal role is to help prepare a woman’s body for pregnancy alongside other female hormones such as Luteinising Hormone and Oestradiol. Progesterone is also produced in smaller quantities by the adrenal glands, and during pregnancy, the placenta.

The reference range of Progesterone in women is:

Follicular: 0.2 – 2.8 nmol/L*
Periovulatory: 0.4 – 38.1 nmol/L*
Luteal: 5.8 – 75.9 nmol/L*
Post-menopausal: 0.2 – 0.4 nmol/L*

Day 21 Progesterone testing:
>30 nmol/L usually indicates ovulation*
<5 nmol/L indicates no ovulation has occurred*

In men, Progesterone is produced at much lower levels and is involved in the production of sperm.

As earlier indicated Progesterone is essential in pregnancy as it prepares the lining of the uterus for implantation of a fertilised egg and helps maintain the embryo for the duration of the pregnancy. An imbalance or low levels of Progesterone resulting from a menstrual cycle where ovulation does not take place are linked to a number of problems including:

– Endometriosis;
– Amenorrhea;
– Infertility;
– Post-Natal Depression; and
– Pre-Menstrual Tension.

Progesterone, alongside other hormones, also stimulates and regulates numerous other functions in the body including:

– Skin elasticity;
– Bone strength;
– Reduced gall bladder activity;
– Normalises blood clotting, vascular tone, zinc and copper levels, cell – oxygen levels and use of bodies fat stores for energy;
– Regulates the immune response and acts as an anti-inflammatory agent;
– Restores libido;
– Brain health;
– Dental health;
– Natural diuretic;
– Natural antidepressant;
– Thyroid function
– Prevention of endometrial cancers (involving the uterus lining) by regulating effects of oestrogen;
– Pancreatic function;
– Signalling of insulin release to maintain blood sugar levels;
– Protecting against breast fibrocystic disease; and
– Maintain muscle tone and improve energy/vitality.

As a women enters the peri-menopause and menopause, Progesterone levels will fluctuate in a downward trajectory prior to a decline in Oestrogen production. This can cause a variety of unwanted symptoms such as mood changes, hot flushes, headaches, night sweats, vaginal dryness, irregular cycles/heavy bleeding.

Progesterone is used in BHRT to relieve these symptoms of the peri-menopause and menopause. It is important to note that Progesterone should always be prescribed alongside Oestrogen.

Progesterone therapy has also proven to be beneficial to the treatment of Endometriosis, Polycystic Ovary Syndrome (PCOS), Post-Natal Depression, Pre-Menstrual Syndrome (PMS) and Fatigue.

* Reference ranges provided by The Doctors Laboratory (TDL) and subject to change if/when methods are re-standardised from time to time.