Are optimum nutrition proteins safe?

I am a licensed physician and am very conscious about choosing supplements. Supplements are almost never regulated by the FDA, because they are not considered food or medicine. The FDA or other institutions typically only get involved if there is some kind of claim for health hazard or mislabelling of products. There is also a lack of evidence based literature to study claims of benefits of supplements. That is why I aim to obtain all my nutritional needs from foods, and I do not actively recommend supplements to any of my patients, unless they are in a situation where they are deficient or when they need higher than usual intake, such as iron deficiency anemia, alcoholism, or pregnancy.

However, I am guilty of looking for a way to boost the results of my workouts. There is literature on PubMed about protein supplementation with respect to muscle hypertrophy. You'll have do dig through them as many are not specifically looking at muscle hypertrophy, and many are animal studies, which would reduce their relevance. The ones that we would be interested in are not ideal studies (i.e. very small population size and not randomized or double-blinded), either. They do hint that protein supplementation may help, however. And some of them specifically address whey. Keep in mind, though, that again these studies are far from perfect, and evidence changes from time to time. Therefore, if someone were to ask me what I thought about whey or similar supplementation, I would say that there is some evidence to support its use, but that nutrition through food is still important.

With respects to safety, excessive protein can be harmful in a variety of cases. It is true that it may harm you if you have kidney or liver problems. In later stages of chronic kidney disease, excessive protein intake may exacerbate uremic symptoms. In liver failure, it is thought that excessive protein intake may lead to or worsen hepatic encephalopathy. In the "average" person and in athletes, daily protein requirement is not that high, in the first place. You most likely obtain enough in your diet. You will have to read up on this as there's no definite concensus on what you need. I do not remember the source but one source I read recommended 1g per kg of your weight for athletes. I have heard the value 1g per lb being thrown around, but that sounds excessive to me. However, medical doctors are not specifically trained in dealing with nutrition to this degree, and I have not read up on this specific question.

I have tried adding approximately 20g a day through supplementation (based on what I already eat and my weight), and over the last 2 weeks (including doubling the duration or intensity of my workouts), I have gained roughly 4 pounds and (subjectively) seen the beginnings of improvement in my body image. I share this result with you, but this in itself is not true evidence in the medical sense.

Now, onto your specific question. I have also looked up safety issues on manufacturers of protein supplements. There have been several FDA issues with manufacturers. Some are about mislabelling (making claims about their product's benefits without saying they have no proof), but some are about cleansliness of the factory itself. For, example, 3 manufacturers owned by the same person were investigated by the FDA for filthiness, and found guilty, starting in 2009 or so.

So far, I have found an instance about the FDA investigating Optimum Nutrition in 2002, for mislabelling. So far, I haven't yet found issues about safety or cleansliness. That doesn't mean there aren't any. And again, there is no sure way to know, unless you worked there or owned the company. This is the same with any supplement product. On the other hand, according to Optimum Nutrition's website, they say they are accredited by the National Sanitation Foundation, and ON is listed on the NSF website. I'm not exactly sure what constitutes as an accreditation.

That's about all I have for you. I have provided links from my internet trawling about this subject.

P.S. There is also a Consumer Reports test in 2010 where they measured heavy metals from multiple samples from multiple protein products. Some were in excess of the maximum recommended daily intake, some were not. Of note though, the manufacturers have made statements that even everyday foods contain heavy metals. I have posted links to Consumer Reports and to Optimum Nutrition's response. Take note of their serving sizes, etc.