How progesterone works
Progesterone is a natural progestogen (corpus luteum hormone) and is secreted by the corpus luteum in women during the second half of the menstrual cycle (also known as the secretion or luteal phase). The corpus luteum forms from the follicle in the ovary after it has released a fertilizable egg into the fallopian tube (ovulation).
Men also produce progesterone – albeit in very small quantities. However, much less is known about its functions in the male body than about its importance in the female organism.
Normal values of progesterone
Progesterone & Pregnancy
Progesterone is also known as the pregnancy hormone. In the second half of the menstrual cycle, it prepares the endometrium for the possible implantation of a fertilized egg. If fertilization does not occur, the corpus luteum dissolves after about ten days. As a result, the progesterone concentration in the blood drops again and menstruation occurs.
During pregnancy, progesterone is also thought to inhibit premature milk production in the breasts so that milk is not provided for the infant until after birth has occurred. In addition, it is assumed that the drop in progesterone levels shortly before birth leads to the onset of the birth process and stimulates uterine muscle activity, i.e. induces labor.
Progesterone as a drug
In medicine, either progesterone capsules to be taken orally are used or the active substance is administered locally (for example as a cream), parenterally (as an infusion) or vaginally.
When taken regularly, twice a day, stable increased hormone concentrations can be achieved in the body.
When is progesterone used?
The administration of progesterone is usually used to compensate for a deficiency of the body’s own hormone. For example, the active ingredient is used to support the luteal phase in the context of assisted reproduction (artificial insemination) and for hormone-related breast pain before the period (mastodynia).
The use during pregnancy is limited in time. The use for menopause syndrome or hormone-related breast pain can also be longer-term.
How progesterone is used
The active ingredient can be taken as a soft capsule or applied locally as a progesterone cream, gel or vaginal tablet. Because the active ingredient is broken down very quickly in the body, it is usually applied twice a day.
What are the side effects of progesterone?
With local application of the hormone (for example, in the form of progesterone cream), side effects are much rarer. Skin rashes and itching are most frequently observed. Headaches and fatigue occur less frequently.
What should be considered when using progesterone?
Contraindications
Progesterone should not be used in:
- unexplained vaginal bleeding
- tumor of the mammary gland or genital organs
- porphyria (disturbed breakdown of red blood pigment)
- severe liver dysfunction
Since externally supplied progesterone interferes with the female hormone balance, the preparations should be used exactly as directed by a physician.
Children and adolescents
Children should not use the hormone because of possible developmental disorders. Progesterone has no relevant benefit in childhood and adolescence, so use in this age group is extremely rare.
Pregnancy and lactation
There is no indication for the use of progesterone during breastfeeding. When used vaginally, studies have not observed any consequences in breastfed infants.
How to obtain medication with progesterone
In Germany, Austria and Switzerland, all forms of progesterone require a prescription, i.e. they are only available in pharmacies after a doctor’s prescription.
