Progesterone is an important hormone that plays a major role in the female reproductive system and pregnancy. Some women notice bodily changes like weight gain or fluid retention when their progesterone levels increase. This leads many to ask: does progesterone make you bigger? Here is a look at the evidence.
How progesterone affects the body
Progesterone is one of the key hormones involved in the menstrual cycle and pregnancy. It is produced mainly by the ovaries during the second half of the menstrual cycle and in early pregnancy.
Some of progesterone’s roles include:
- Preparing the uterus for pregnancy
- Maintaining pregnancy
- Balancing estrogen effects
Progesterone levels rise significantly after ovulation, peak midway through the luteal phase leading up to menstruation, and then drop dramatically when menstruation starts if pregnancy has not occurred.
If pregnancy does occur, progesterone levels stay elevated to support the pregnancy. The placenta starts producing large amounts of progesterone after 8 weeks of pregnancy to support fetal development.
Progesterone effects that can increase size
The high progesterone levels during the luteal phase and pregnancy cause several changes in the body that can make some women feel “bigger.” These effects include:
Breast changes
Progesterone stimulates development of the mammary glands in preparation for breastfeeding. This can make breasts feel tender, swollen, or fuller. The areola may also darken in color.
Fluid retention
Progesterone relaxes smooth muscle tissue in blood vessels, which can lead to vasodilation and increased blood flow. This effect prompts the kidneys to retain more fluid. Some women notice swelling in the fingers, legs, or other parts of the body as a result.
Bloating
Progesterone slows digestion to allow better nutrient absorption for pregnancy. But this can also cause abdominal bloating, distension, gas, and constipation for some women.
Weight gain
Progesterone boosts appetite and fat storage in preparation for the caloric needs of pregnancy and breastfeeding. This can result in some weight gain, although the amount varies widely between women.
Joint laxity
Progesterone relaxes ligaments and tendons in the body, which can increase flexibility in joints like the hips and pubic bone. This prepares the body for childbirth but may also lead to feelings of pelvic heaviness or instability.
How much size change is normal?
Most women experience mild to moderate increases in breast size, bloating, and water retention related to progesterone. However, the amount of change varies quite a bit from person to person.
Factors like the degree of natural hormone fluctuations or baseline weight can impact how obvious progesterone-related changes are. Changes tend to be most pronounced in the luteal phase or early pregnancy when progesterone peaks.
Here are some general guidelines on normal size changes:
Breasts
An increase of up to 1 cup size is considered normal. Breasts may feel swollen and tender to the touch.
Bloating
Abdominal girth may expand up to 2 inches (5 cm) from bloating. Clothes may feel tighter around the waist and hips.
Water retention
Weight gain of 2-4 pounds (0.9-1.8 kg) from fluid retention is common. This is often temporary and reversed shortly after menstruation starts.
Joint laxity
Minor discomfort or feelings of instability in the pubic bone and hips are common. Significantly loose or overly mobile joints could indicate a pelvic floor disorder.
When to be concerned about size changes
In some cases, progesterone-related changes may become more severe and disruptive:
- Breast size increase over 2 cup sizes
- Abdominal bloating over 5 cm (2 inches)
- Unexplained weight gain over 5 pounds
- Sudden swelling in the limbs
- Persistent pelvic or hip pain
Sudden or severe fluid retention or breast engorgement beyond normal levels may require evaluation to rule out underlying conditions like:
- Hormone imbalances
- Kidney disease
- Blood clots
- Heart failure
- Pelvic floor dysfunction
- Fibrocystic breast disease
Tips to manage progesterone-related size changes
Here are some healthy ways to help cope with increased breast size, bloating, water retention or joint looseness due to progesterone shifts:
Wear loose, comfortable clothing.
Choose tops, dresses and pants in stretchy fabrics with a loose silhoutte. Avoid bras or waistbands that dig in.
Reduce salt intake.
Limiting sodium can help minimize fluid retention and swelling.
Increase magnesium and B6.
These nutrients help regulate fluid balance and progesterone effects. Good sources include nuts, seeds, legumes, bananas, and avocados.
Boost physical activity.
Light exercise improves circulation and helps the body flush out excess fluid.
Try magnesium oil.
Transdermal magnesium applied to the skin may help relax smooth muscle tissue.
Use hot or cold therapy.
Heat relieves breast tenderness while cold packs help reduce swelling.
Get a prenatal massage.
Massage improves lymph drainage and may provide pelvic pain relief.
Wear a belly band.
An elastic pregnancy belt provides abdominal support and comfort.
The bottom line
Mild to moderate increases in breast size, abdominal girth, water retention and joint laxity are common progesterone effects that some women experience cyclically or during early pregnancy. However, sudden severe changes or disruption in quality of life may require medical evaluation. Focusing on healthy lifestyle measures can help manage the physical impact in the meantime.
Frequently Asked Questions
Does progesterone actually increase body size?
Progesterone does not directly increase fat storage or growth. However, it stimulates changes like fluid retention that can temporarily increase measurements like breast cup size, abdominal girth or weight. Underlying fat or tissue does not increase.
Are progesterone-related changes preventable?
It is not possible to completely prevent effects like breast swelling or bloating when progesterone levels rise. However, a healthy diet, regular exercise, and stress management can reduce severity. Maintaining a stable body weight also minimizes fluctuations.
How long do progesterone-related changes last?
Progesterone-related body changes are temporary and subside once hormone levels drop back down. Breast size decreases, abdominal bloating resolves, and excess fluid flushes out within 1-2 weeks after progesterone peak.
Should I take natural progesterone to minimize effects?
Natural micronized progesterone is sometimes used to provide progesterone benefits without amplified side effects. However, more evidence is still needed to confirm advantages. Work closely with a healthcare provider when considering supplementation.
When should I be concerned about breast size changes?
Noticeable increases in breast size up to 1 cup are usually normal. Signs of possible abnormal hormone levels or disorders include breast growth over 2 cups, nipple discharge, severe pain, or lumps. Seek medical advice about significant or prolonged changes.