Women have two main reproductive hormones: estrogen and progesterone. Often, estrogen gets a lot of the spotlight but today we’re going to talk about the yin to estrogen’s yang — progesterone!

Since progesterone doesn’t get as much attention, many women don’t know how critical this hormone is when trying to conceive. Spoiler alert — it can make or break your chances at conception! Keep reading to learn more about progesterone and why it’s so important to test your levels.

What is progesterone and why is it important?

Progesterone is the hormone that is elevated during the second half of your cycle (the luteal phase). After ovulation occurs, the empty follicle from which the egg was released (also called the corpus luteum) produces progesterone.

Progesterone’s job is to stabilize the uterine lining and make it “sticky” enough for an embryo to implant, should the egg be fertilized by sperm. It also creates a healthy uterine environment where the embryo can get nutrients and thrive. In order to do this, progesterone needs to rise to an optimal level and remain adequately elevated for several days during the luteal phase.

Aside from conception, progesterone also plays roles in our overall health. Low progesterone can cause unwanted symptoms such as PMS, mood swings, and can make it more difficult to conceive.

Why should I test my progesterone levels?

Understanding your progesterone levels can help you reach your fertility goals faster. As we mentioned, not enough progesterone following ovulation can make it more difficult to conceive. Ensuring you have enough progesterone for long enough can help you better understand your chances at conception.

Additionally, when progesterone levels drop too early, this can cause a shortened luteal phase. Studies show the most common days for implantation to occur are days 8, 9, and 10 post ovulation. If your progesterone levels drop before day 10 post-ovulation, it can be harder for implantation to occur, meaning it’s also more difficult to get pregnant.

How do I test my progesterone levels?

There are two main ways to test progesterone: a serum progesterone blood test or a PdG (progesterone metabolite) urine test. Both have their pros and cons, so it’s best to understand how each could help you.

Serum progesterone blood test

Serum progesterone blood tests are taken on cycle day 21, about 7 days post ovulation when progesterone levels should be high. While progesterone blood tests give a quantitative progesterone level and can confirm ovulation, they one show your levels at that single point in time. This can be a problem since, as we know, progesterone needs to remain elevated for several days during the luteal phase in order to allow for the best possible chance at conception.

Additionally, a single progesterone blood test may provide you with inaccurate assumptions about your levels depending on when you take it. Studies show that serum progesterone levels fluctuate drastically — up to 8 fold in a single 90-minute time period for the same healthy patient! That means if you get a blood draw in the morning, you could get very different results than if you were to test in the afternoon.

While serum progesterone blood tests are effective at confirming whether or not you ovulated, they fall short of showing your levels over time in order to ensure the best possible chance at conception. Which brings us to PdG testing.

PdG testing

Pregnanediol Glucuronide (or PdG for short) is the main urinary metabolite of progesterone. After progesterone circulates through the bloodstream, it is metabolized by the liver and released from the body as PdG in urine. Studies show that PdG levels in first morning urine show an average of all progesterone blood levels from the previous day.

Additionally, testing PdG in urine is non-invasive, meaning you can easily track your levels for the critical days during the luteal phase. Testing multiple days in a row can give you a better idea of your levels over time and your chances at conception.

Proov PdG tests are the first and only CE marked PdG tests to confirm successful ovulation at home. Proov PdG tests are non-invasive, meaning you can easily test your levels for several days from the comfort of your own bathroom. Successful ovulation refers to an ovulatory event in which an egg was released and PdG levels remained adequately elevated for long enough to allow for the best possible chance at conception.

Our patented testing protocol recommends testing on days 7, 8, 9, and 10 past peak fertility (i.e. a positive LH test). While a single positive PdG test confirms an egg was released, we like to see 3-4 positive PdG tests during this window (with a positive on day 10) to confirm that successful ovulation did in fact occur. If you get anything less than 3 positive PdG tests or do not get a positive on day 10, this could be a sign of “weak” ovulation or low PdG levels which could make it more difficult to conceive.

Our patented testing protocol recommends testing on days 7, 8, 9, and 10 past peak fertility (i.e. a positive LH test). While a single positive PdG test confirms an egg was released, we like to see 3-4 positive PdG tests during this window (with a positive on day 10) to confirm that successful ovulation did in fact occur. If you get anything less than 3 positive PdG tests or do not get a positive on day 10, this could be a sign of “weak” ovulation or low PdG levels which could make it more difficult to conceive.

What should I do if my progesterone levels are low?

If a progesterone blood test or PdG test results show your levels could use a boost, don’t worry! There are plenty of ways to raise progesterone levels. Here are some of our favourites:

• Diet changes: The food we eat does not directly contain progesterone, but some foods have progesterone-boosting properties. If you’re looking to raise progesterone levels, you may want to try foods such as: Brussels sprouts, spinach, pumpkin, beans, broccoli, and nuts, among others.
• Seed cycling: Seed cycling is a natural way to promote a healthy hormone balance. It involves eating certain seeds during certain phases of your cycle: pumpkin and flax during the first half to promote estrogen production, and sunflower and sesame seeds during the second half to promote progesterone.
• Herbal supplements: Some over-the-counter herbal supplements have been shown to naturally increase progesterone levels. Some good ones to start with are maca, ashwagandha, and vitex (chasteberry).
• Prescription-level supplements: If natural options don’t work or you’re looking for something stronger, we recommend consulting your doctor to discuss progesterone supplements. These typically require a prescription.

The more you understand about your progesterone levels, the better equipped you are on your trying to conceive journey!
Proov PdG tests are available in the UK on our website, proovtest.com.