HMS 90 stands for Humanized Milk Serum 90% protein. It is the way this undenatured whey protein isolate used to be labeled in Canada prior to November 2007 while in other countries it was and is known as Immunocal.
In 2007 Health Canada formally recognized HMS 90 as having health benefits based on solid scientific proof and allowed the company Immunotec Inc. to rename it to Immunocal to reflect the following health claim – "a natural source of glutathione precursor cysteine for maintenance of strong immune system." The Natural Health Product Directorate (NHPD) in Health Canada’s division responsible for the evaluation of safety, efficacy and quality of Natural Health Products, has issued Immunotec Inc. a Natural Product Number (NPN) "based on the credibility, strength and quality of evidence provided to support their claim."
Why couldn't Immunocal be named so in Canada before? It is because prior to such regulatory approval by Health Canada the name of the natural product in this country could not contain any "immune" word in it.
Although HMS 90 is now labeled Immunocal in Canada, Canadian customers still refer to Immunocal by its old name sometimes.