I finally found the exact way, even with exact measurements. Just that I don't have the means to make it at home.
For all those who are interested in making PM extract on their own, here is how.
BEST MODES FOR CARRYING OUT THE INVENTION
A better understanding of the present invention may be obtained in light of the following examples which are set forth to illustrate, but are not to be construed to limit the present invention.
EXAMPLE 1 Preparation of Pueraria mirifica Extract
100 g of the tuber of Pueraria mirifica was cleansed, dried at 70 °C for about 5 hours by use of a hot-air drier, and pulverized. To the resulting plant pieces was added 500 mL of a mixture of methanol and water (80/20 v/v), followed by the extraction at 50 °C for about 6 hours. After being filtered, the extract was concentrated in a vacuum to remove the solvent. The concentrate was freeze-dried leaving a brownish solid which was then measured for isoflavone content. Contents of isoflavones in the extract derived from the tuber of Pueraria mirifica are given in Table 1, below.
TABLE 1 Contents of Isoflavones in Extract Derived from Tuber of Pueraria mirifica Isoflavone Content (mg/lOOg)
Daidzin 51.0
Daidzein 8.1
Genistin 12.0
Genistein 2.0
Puerarin 96.0
As shown in Table 1, the above processes can prepare the best quality of Pueraria mirifica powder. The powder prepared according to the above processes was measured to be high in its contents of isoflavone and other phytoestrogens. Phytoestrogens obtained from the plant included miroesterol, daidzin, genistin, genistein, beta-sitosterol, stigmasterol, coumestrol, puerarin, campesterol, mirificoumestan, kwakhurin, and mirificin (Bounds and Pope, 1960; Ingham et al., 1986a; Ingham et al, 1986b; Ingham et al., 1988).
But if you happen to make it please be careful, as the extract is extremely strong. At the place I found it they warned multiple times about the strength. If you make a cream or lotion with it, the maximum one should use is 4% of the topical you are trying to make. If anyone is interested in the exact recipe for lotions or creams, just say so and I will load them up as well.