Hi mate
A lot of people tend to think of anavar has not being suppressive. Yet the guys on here I'm sure would agree with me when I say it can suppress your own production of testosterone, to some degree.
Anavar has a half life of about 8 hours, so theoretically, at least, the last dose should be out of your system within 24 hours. However, if the blood test is likely to include testing for AAS then you might be looking at weeks to months.
I'd say, personally speaking, that you should refrain from taking Anavar at least 4 weeks prior to your blood panel. If you're getting symptoms of low testosterone make sure they test for:
a. Total testosterone
b. Bioavailable or free testosterone
c. LH (Leutinising Hormone)
d. FSH (Follicle Stimulating Hormone)
e. Oestriadol
f. *Progesterone.
If you're deficient in testosterone, then your doctor should investigate why? In other words, are you Primary Hypogonadal, Secondary Hypogonadal, or both?
In Primary cases this will be often be noted by low T and nomal or higher LH/FSH levels, because your testes aren't producing T hormone. If you're Secondary, then your Total T might be high or normal, but the LH and/or FSH will be low or lower than normal. Secondary would indicate a Pituitary Gland malfunction in most cases. Both can be sorted by therapy. Progestoerone is an optional but in some cases, a very important addition. Nevertheless, make sure they test for the rest of the above at least.
All the best.
Craig