Or so I was told by an allergist. Mine seems to have been a fluke occurrence, and I don't think the supplementation was related. But you should definitely keep an eye on it. Only, some may not notice this immediately. It's also very foolish for any company to recommend a daily dosage for all people.
Some people are large and some are small.
So, be careful when taking anything. In regards to the first writer having these unfortunate discomforts, I sympathize, but we all learn some things the hard way. Taking this brand or that brand should be less of a concern than what the actual ingredients in the supplements are. If you weigh just 150 lbs a safe and effective daily dose of HMB is 2.5 grams or 2,500 milligrams over the course of an entire day. Taking smaller doses is much safer and effective.