I copied this thread from MesoRX forum as I had found it being very useful.

QUESTION:

I stoped taking Birth Controll pills for a wile, i make my BF wear a condom. hes getting fusterated and wanted me on BC again. I had a few questions regarding BC and winny/var/primo. If one is on a cycle of winny/var/primo is a woman more fertile or less fertile? And how would taking the female hormone effect it? If wile on winny/var/primo a woman is temparly sterile then i can say cool and wait till after a cycle to start on them.

And i say winny/var/primo as in a single cycle, not all three at once.

ANSWER:

Us fellas here are unabashadley ignorant as to the complexities of the female anatomy. That said, I first began to educate myself on how the female menstrual works after my wife received "the shot", which is nothing but a mega dose of progesterone that completely stalls the endocrine system for three months or more.
After a two months of this shot, which, like I said lasts three or more months, she couldn't take its side effects. So, I began my research.

I'll just tell you that the way to cure the shot is 3 - 5 days of clomid at 50mg Ed. For a woman that is all that is required to jump start the menstrual cycle... crazy when you compare to a man's PCT.

But basically, this is what you're looking at on a typical month:


Testosterone isn't accounted for in this graph because the world has turned feminist and testosterone represents all that is evil
But we know what testosterone will do because of the inherent connection to LH and estrogen. So, just draw a shadow line underneath the estrodiol and that will give you a basic idea. Of course every woman is different just like every man; thus the specific shape of the graph will vary, but the derivative will remain the same.
Now, to begin to answer your question you need to understand the relation between all these hormones. I started to type out an explanation but then I found this little blurb on about.com so I'll let this get the ball rolling:

So, as you can see the estrogen in your birth control works by suppressing LH and FSH, via the negative feedback loop, preventing ovulation from occuring. Just in the same way that AAS shuts down the HPTA in men, everything kinda freezes in the presence of this disproportionately high hormone. Progesterone on the otherhand, works by tricking your body into thinking its already pregnant; thickening the walls of the uterus, blocking egg implantation, and creating the cervical mucus plug to block sperm. That is why progesterone rises after ovulation in a normal cycle. When you take testosterone you accomplish the same thing as taking estrogen, but as you are aware, with testosterone you run the risk of virilization. Anavar, winstrol, and primo should simulate the effect. So, I would say that so long as you keep everything reasonable you should be able to run BC and your choice AAS at the same time.
Additionally, I want to relay what I've heard about more and more women running BC continuously for 12 week cycles instead of the traditional 3/1 week split. Apparently, the continuity granted by the steadiness of hormone levels is favored by most women who tried it. I ran across this article
a few minutes ago when I was digging up the other part of your answer: http://womenshealth.about.com/cs/bir...ntnusbcuse.htm
In part, this is what they had to say,

This is just a thought of course, but I would think that not only would it be ok to be on BC while using var or whatever, but you might even want to use it for the entire time.

So, that's pretty much all I know about you crazy creatures

Van

Scientific Research: Perturbations of the human menstrual cycle by oxymetholone

1: Am J Obstet Gynecol. 1975 Jan 1;121(1):121-6.
Perturbations of the human menstrual cycle by oxymetholone
* Cox DW,
* Heinrichs WL,
* Paulsen AC,
* Conrad SH,
* Schiller HS,
* Hezl MR,
* Herrmann WL.
The luteolytic activity of oxymetholone, and anabolic steroid, has been evaluated in 10 women. Administration early in the follicular phase of the cycle inhibited ovulation and prolonged the duration of the cycles in 2 of 3 subjects, but treatment beginning on Day 10 (3 subjects) did not prevent ovulation, although subsequent plasma progesterone concentrations were reduced. Treatment after ovulation (4 subjects) suppressed progesterone levels by 50 to 80 per cent and shortened cycle length by 6 to 8 days. Side effects were weight gain and bromosulfophthalein retention. The most likely mechanisms producing these perturbations are the inhibition of luteinizing hormone release early in the cycle and, later, inhibition of progesterone biosynthesis.

PIP: 10 ovulating women were treated with oxymetholone in 1 of 3 ways: 1) 50 mg twice daily every other day starting on the sixth day of the treatment cycle (early follicular phase), 2) 50 mg twice daily every other day starting in the late follicular phase (tenth day), or 3) 100 mg daily starting in early luteal phase. 2 women treated in early follicular phase had ovulation suppression and cycles prolonged 9 to 10 days, with progesterone suppressed by ovulated, and a third had a 71% suppression of progesterone. In the third group, cycle lengths were shortened due to a luteal phase shortening of 6 to 8 days, with progesterone values decreased 53 to 81%. Side effects noted were: weight gain (9 out of 10 patients) transient nausea, and increased bromsulphalein retention

__________________________________________________ ___________________________
1: Am J Obstet Gynecol. 1973 Sep 1;117(1):121-5.
Induction of premature menstruation with anabolic steroids.
* Bolch OH Jr,
* Warren JC.

PIP: To determine the mechanism of the effect of certain anabolic steroids on menstruation induction and to evaluate this effect as an interceptor of early pregnancy, the luteal phase length was studied in the cycles of women ranging in age from 21 to 37 years after postovulatory treatment with 7 different anabolic steroids. Basal body temperature records were kept and endometrial biopsies were obtained late in the pretreatment control periods to confirm ovulation.

2 steroids which had been proven to shorten the luteal cycle phase were administered as follows: Nandrolone phenpropionate was given in a daily 50-mg dose intramuscularly for 3 days. 30 mg of oxymetholone was administered orally every 6 hours for 4 days. The previously untested steroids were administered orally in evenly divided doses every 6 hours for 4 days as follows: oxandrolone, 60 mg daily; stanozolol, 28 mg; methandrostenolone, 60 mg; fluoxymesterone, 40 mg; and ethylestrenol, 30 mg.

Plasma progesterone and gonadotropins were measured by radioimmunoassay of blood samples taken 7 days after ovulation. Nandrolone and oxymetholone were found to significantly shorten cycle and luteal phase lengths and depress plasma LH and progesterone levels as compared to control cycles. Nandrolone also significantly depressed plasma FSH levels. Of the 5 new drugs, only ethylestrenol significantly shortened luteal phase length (p less than .001). This finding is questioned by the small sample size and thus the use of this steroid as a menstruation inducer is considered questionable. The mechanism of the effect of nandrolone and oxymetholone appears to be due to their antigonadotropic action that only secondarily reduces progesterone levels. Whether these steroids can affect human chorionic gonadotropin and thus cripple the corpus luteum and interrupt early pregnancy needs further research.

Hope this will help some of you.