Here, this is from another forum:
WHEN should you take soy?
You take Soy Isoflavones, like Clomid, on either CD 1-5, 2-6, 3-7, 4-8 or 5-9.
If you take soy Isoflavones during the later time bracket, for example CD 5-9, you shall strengthen the egg that has already started growing producing a healthier egg. The earlier in your cycle you take It, the higher your chance of releasing multiple eggs but these eggs will not be as mature as the eggs grown from taking Soy later.�
A lot of women will choose the middle cycle (3 -7) allowing time for a strong and healthy egg to develop without erasing the chance of a second egg being developed and released.
1-5 = You produce more eggs, and ovulate sooner, with a stronger ovulation.
2-6 = You produce more eggs than usual, but not as many as taking it 1-5. Eggs may be more mature, and ovulation will be slightly more strong than 1-5.
3-7 = The best of both worlds, a few more eggs, and all eggs will be strong & mature, and ovulation will be a lot stronger than 1-5.
4-8 = No more eggs will be produced, but the ones already there, will be matured alot more than usual, and ovulation will be very strong. Ovulation may only be brought forward a teeny bit.
5-9 = You'll have one very mature strong egg, from the ones you already produced on your own. Ovulation will either happen when it usually does, or a few days later, but your egg will be of great quality.
What DOSAGE should you take?
The dose is really�up to you but you should always use the lowest amount that works for you.
With Clomid the starting dose is 50mg. Soy Isoflavones are said to be half the strength of Clomid, so it makes sense for the starting dose to be 100mg.
The trouble with 100mg of soy is that the capsules tend to come as 40mg. So you have a choice of starting at 80mg or 120mg.
I would recommend that if you know that you do ovulate without taking soy then you should start with 80mg.
And if you know that you don't usually ovulate you can start with 120mg.
Some women change the dose on different days. So they may start at 120mg for the first 3 days then give an extra boost for the last 2 days with 160mg.�
Use the lowest dose possible for yourself. It is said that it takes 3months to get the full benefits of what you are taking. NEVER EXCEED 200mg/day.