Blood vs. Urine
“How do Proov tests compare to a progesterone blood test?”
I get asked that question almost on a weekly basis. The simple answer is that blood progesterone levels and urine progesterone metabolite (PdG) levels correlate extremely well. The research is solid, but I wanted to answer an even tougher question: “Can Proov tests replace blood progesterone tests?” So I decided to put Proov to the test!
First, a little background, since it’s important to understand what we’re actually testing. Progesterone is the hormone produced AFTER ovulation. Medical professionals use blood progesterone tests to confirm ovulation. Progesterone levels greater than 5 ng/ml are proof that ovulation occurred. Additionally, doctors typically like to see progesterone levels greater than 10-12 ng/ml in order to support a healthy pregnancy. Since most blood progesterone tests require a doctor referral and a lab visit, many women don’t have access to this type of testing. Another option is the in-home progesterone testing kit that only needs a finger prick worth of blood, which then gets mailed to a lab for analysis. Since I’m not under a doctor’s care, I had to use option B, the mail-in kit.
Proov tests work a little differently. They measure progesterone metabolites, or PdG, in the urine and can be both used and read at home. So no lab, no blood draws, no mailing of samples, and no waiting on results. So, now onto the actual test!
I started my period on October 2nd and started tracking my cycle with the free Femometer app (available on ios/android). I used this app because I love the feature that allows you to upload an image of your ovulation test that the app scores as low, high, or peak. It really helps me track my tests and measure my LH levels over time. I have a ~26 day cycle so I began testing on day 10.
On day 10, I took both an ovulation (LH) test and a Proov (PdG) test. Both were negative. The day 10 Proov test also acted as my baseline test. I continued to test ovulation (LH) daily until getting a “high” test on the evening of day 13 and a “peak” test the morning of day 14. On day 15, I tested LH again and it was only a “high”, suggesting that my LH surged on day 14 and that I could have ovulated. Thus, I started testing my progesterone levels with the Proov tests. Again on day 15, one day after my LH surge, the Proov strip was still negative. On day 16, two days after my LH surge, the Proov strips was negative, but the test line was significantly lighter, suggesting my progesterone was increasing!
This is kind of embarrassing to say, but I couldn’t collect my blood sample alone – I had to recruit help. I’m not sure how diabetics do it, but I just couldn’t prick my own finger. Luckily for me, my pal Patrick was there to help. First I had to register the test on their website. They asked all kinds of personal questions such as number of pregnancies, number of miscarriages, months I have been TTC, and a bunch of other invasive questioning, all of which had to be answered before I could even activate my test kit.
So to recap, I am currently on cycle day 17, 3 days after my LH surge and my Proov test strip was positive. So now on to the fun part, collecting a blood sample and sending it to the lab.
Then of day 17, my Proov strip was positive! I’m not sure it photographs well, but when I look straight at it, up close, I can still see a faint grey test line. However, according to the directions, my test was positive.
I collected the blood for the test and sent it in on October 18th. I received an email on November 5th with the results of my blood progesterone test. It took about 3 weeks to get my results!
Drumroll: my results were 20.50 nmol/L (European units), which is equivalent to 6.44 ng/ml (US units). And since anything over 5 ng/ml indicates I ovulated, these results were consistent with my urine results.
So my conclusion, can Proov (urine progesterone strips) replace blood progesterone tests? Yes, absolutely!
Pros of Proov:
- Fast, results in 5 minutes
- No need to share personal information or leave the privacy of your bathroom
- Simple, what could be easier than peeing?
- Cost effective. For $40 I can measure progesterone 7 different times
Pros of blood progesterone testing:
- I got an exact concentration of progesterone. However, since anything over 5 ng/ml is normal, do I even need an exact value? The extra pain, cost, and waiting pretty much negated the pro of getting an exact number, at least in my opinion.