Progesterone plays a central role in hormone balance across life stages. It influences sleep quality, mood stability, stress resilience, and menstrual cycle regulation—and fluctuations can contribute to symptoms like poor sleep, anxiety, migraines, PMS, or heavy or irregular periods.

Testing your levels can help you better understand patterns that may be affecting fertility, cycle changes, perimenopause, metabolism, and overall wellbeing.

With Function, you can purchase progesterone testing at any time as an On-Demand Test.

How do I purchase progesterone testing? 

If you’re not already a Function member, join here. Then, log in to your account and select “Get Lab Tests” to see all tests available for purchase. 

Once you’ve purchased a progesterone test, you’ll be prompted to schedule a lab visit. 

When should I schedule progesterone testing? 

If you have a menstrual cycle, the ideal time to test is 5-7 days after ovulation, during the luteal phase. For those with regular 28-day cycles, this is usually 19-21 days after the start of your period. However, timing should be adjusted based on your specific cycle length and ovulation day.

If you do not have a menstrual cycle, you can test progesterone at any time. 

What is the luteal phase and why does it matter for progesterone testing? 

The luteal phase is the second half of your menstrual cycle. It starts after ovulation and ends when your period begins, typically lasting 12-14 days.

Progesterone levels rise significantly after ovulation. Testing during the luteal phase confirms whether ovulation occurred and whether your body is producing adequate progesterone to support a potential pregnancy. Low progesterone in the luteal phase can contribute to difficulty conceiving or early pregnancy loss.

How do I schedule if my period is irregular?  

Start by tracking ovulation signs for at least one cycle. You can track ovulation using ovulation predictor kits, basal body temperature charting, cervical mucus monitoring, or fertility tracking apps. 

Once you detect ovulation, count forward 7 days for testing in the luteal phase.

Can I test progesterone at other points in my cycle?

We recommend testing progesterone during the luteal phase, but you have the option to schedule at other times in your cycle depending on what you’d like to learn. 

If you choose to test multiple times, comparisons are most reliable if you test during the same phase each time.

What do I do if I schedule progesterone testing and then my cycle changes that month?

Reach out to our support team to reschedule your lab visit. 

Is testing progesterone helpful if I’m in perimenopause or menopause? 

Yes. Progesterone affects brain chemistry, sleep, bone health, and response to hormone therapy, even when cycles have stopped.

Can I test progesterone if I’m on birth control? 

We do not recommend testing progesterone for members on hormonal birth control. Most birth control methods suppress natural progesterone production, so levels are typically low or undetectable while on contraception.

Is progesterone testing useful for men? 

Yes. Progesterone is part of the adrenal and testosterone production pathways and plays a role in stress response and brain function. Testing may be useful for men experiencing sleep problems, fatigue, stress intolerance, and low libido, as these symptoms can be associated with hormone pathway imbalances involving progesterone.

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