Hydroxymethyl Butyrate (HMB) Side Effects and Warnings

Safety Issues

HMB seems to be safe when taken at standard doses. ¹ Clinical trials have not found any significant adverse effects with short-term HMB use. ² Short- and long-term toxicological studies in animals have also found no evidence of harm. ³ However, full safety studies have not been performed, so HMB should not be used by young children, pregnant or nursing women, or those with severe liver or kidney disease, except on the advice of a physician.

As with all supplements taken in very large doses, it is important to purchase a quality product, as an impurity present even in very small percentages could add up to a real problem.