Reflex nutrition hmb calcium beta hydroxy beta methylbutyrate is an active metabolite of leucine and features an anti catabolic effect on the muscler reflex nutrition hmb helps to reduce muscle breakdown and is more effective than leucine when used for this purposer reflex nutrition hmb provides 500mg hmb per capsule hmb tends to be most effective in the dosage range of 1 3g daily in order to help minimise muscle mass loss and reduce the rate of muscle breakdownr reflex nutrition hmb has