Here is the whole bit of info I saved from a very old thread...
Soya Isoflavones are derived from soya beans. They have been dubbed “the natural Clomid,”
As they work in pretty much an identical manner.
Just like Clomid; Soya Isoflavones work by tricking your body into thinking its low on oestrogen. Your body then kick starts production of FSH (Follicle-stimulating hormone) followed by LH (Luteinizing hormone) Which are both necessary to release Healthy Eggs during ovulation.
FSH is released at the start of the menstrual cycle; it stimulates the growth of an immature egg into a fully matured egg. When the egg has matured your body then releases a surge of LH. LH is the hormone that tells the ovary to release the egg.
WHEN?
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 CD5-9, 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 Soya 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 that 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 alot 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.
DOSE?
The dose is really down to you but you should always use the lowest amount that works for you.
With Clomid the starting dose is 100mg. Soya 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 soya is that the capsules tend to come as 40mg. So you have a choice of starting at 80mg.
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.
As I have said though, use the lowest dose possible for yourself. If you ovulate using 120mg/day stick to that for a few cycles. GIVE IT A CHANCE. It is said that it takes 3months to get the full benefits of what you are taking. NEVER EXCEED 200mg/day.
OTHER BENEFITS?
The following potential health benefits are attributed to Isoflavones:
Reduce heart disease risk
Protect against prostate problems
improve bone health
Reduce cancer risk
SIDE EFFECTS?
As with any medication, taking Soya Isoflavones may cause side effects such as:
Nausea
Headaches
Dizziness
Hot flushes
Night sweats
Cramping
Diarrhoea
Lack of fertile cm
Thrush
Obviously the higher the dose you take the higher your chance of experiencing side effects.
DO NOT TAKE SOYA ISOFLAVONES WITHOUT CONSULTING A DOCTOR IF YOU HAVE ANY OF THE FOLLOWING:
Breast cancer, hepatic disease, prostate cancer, kidney disease, taking hormone treatments, thyroid disease, and allergies to soy, peanuts or other legumes.
Soy Isoflavones should not be taken while breastfeeding or pregnant.
Soy Isoflavones may interact with the following medications; androstenedione, antibiotics, clomiphene, DHEA, contraceptives and other female hormones, finasteride, raloxifene, red clover, tamoxifen, testosterone and other male hormones, thyroid hormones, and toremifene.
NOTE: Just like Clomid, Soya Isoflavones may not help some women at all!
Although research carried out on FF has shown that 77% of women taking Soya Isoflavones on the stated days at the stated doses, got there BFP on their first cycle taking them!