I found Roberts question (slow growth) about the validity of 17OHP testing to be very timely - and would also love to hear any opinions. I have been 'juggling' medication as a result of varying 17OHP blood levels (along with Testosterone and Plasma Renin - which always seem to be about right) for more than a year under a new (to me) endo. As a woman (I'm in my 40's) the 'normal' range is supposed to be between 0.3 - 12.1 nmol/L. Whilst on the same level of medication recently - and with blood taken less than 4 weeks apart (3rd March and 31st March) one reading came out as 7.3nmol/L (fine) and then when taken three times in a day - on the latter date - came out as 176 nmol/L when taken at 7.35am before medication, 117 at 12.35pm and 137 at 5.15pm. I am still awaiting an explanation from my endo - but thought I'd post this to add my 2 cents worth on the validity of this test too.