I agree. I wouldn't waste money on a soy protein powder.

And if you don't like soy products like tofu, tempeh, or all the mock meat stuff then ok. But it's gonna take a huge amount of those weak plant estrogens to effect you test, and its gonna take that extended period of time.

But the BV rating is a crock. It is not considered reliable or accurate by today's standards and just about every method that has come after it has been shot down. I think some of us are suffering from selective research syndrome.

Consider this for an updated perspective.

Nutritional Value of [15N]-Soy Portein Isolate Assessed from Ileal Digestibility and Postprandial Protein Utilization in Humans

François Mariotti*, Sylvain Mahé*2, Robert Benamouzig, Catherine Luengo*, Sophie Daré*, Claire Gaudichon* and Daniel Tomé*

* Institut National de la Recherche Agronomique, Unité de Nutrition Humaine et de Physiologie Intestinale, Institut National Agronomique Paris-Grignon, 75231 Paris Cédex 05, France and Service de Gastroentérologie, Hôpital Avicenne, 93009 Bobigny, France.

ABSTRACT
The purpose of this work was to assess the true oro-ilea digestibility, and to concurrently quantify the deamination of absorbed dietary nitrogen to examine the postprandial nutritional value of a soy protein isolate (SPI) in humans. To assess bioavailability and bioutilization of SPI, 10 healthy volunteers ingested 30 g of SPI, intrinsically and uniformly [15N]-labeled, added with 100 g of sucrose and water up to a final volume of 500 mL. True ileal digestibility was assessed by the [15N]-dilution method for 8 h by means of a naso-intestinal intubation technique. To describe and quantify exogenous nitrogen deamination for the same time period, urine and plasma samples were collected. True oro-ileal digestibilityof SPI nitrogen was 91%. The amount of absorbed SPI amino acids used for nonoxidative disposal, i.e., postprandial biological value, was 86% 8 h after meal ingestion. Hence, net postprandial protein utilization of SPI was 78%. Compared to previous data that were assessed under the same condition in humans, the nutritional value of SPI is 92% of that in milk protein concentrate.

Now, the common BV value for soy protein is around 74 or 75%. The PDCAAS (Protein Digestibility Corrected Amino Acid Score) is .91 (1 is the higest). In this study the true ileal digistibility of soy was found to be 91%. The BV is always found to underestimate values compared to new methods.