# Progesterone level - blood test



## Keeping the faith (Apr 1, 2012)

Hi.  I stopped taking progesterone last night.  I was on 2 x 400mg daily, but had reduced my doseage to 1 x 400mg for 5 days prior to stopping.  I'm going to book an appointment with my doctor to get my progesterone level tested.  How long does it take progesterone to leave the system?  Is Friday too soon for a test?

Thanks xx


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## Mistletoe (Holly) (Jan 1, 2007)

Why do you feel you need to have the level measured?
Have you had particular problems in the past?

By week 12 the placenta has taken over from the corpus luteum/supplements making enough progesterone to support the pregnancy itself.

Have a chat with your doctor.
As for the original question it is highly variable. Studies have shown that it can be as short as 2.5 days to as long as 16 days for supplements to completely leave the system.

Micromedex quotes half life of progesterone in assisted reproductive technology to be 25.91 h +/- 6.15 h to 45 h +/- 34.70 h. The half life is the time it takes for the concentration in the blood to drop by half, and we usually say 5 times that figure for it to be completely out of the system.


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## Keeping the faith (Apr 1, 2012)

This is my first pregnancy so I've no previous issues with progesterone.  It's more a fear that for some reason my placenta wont have kicked in properly.  

I have an appointment with my doctor on Friday for a couple of other things so will discuss then.

Thanks for the advice xx


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