Blackmores BIO C 500 Sustained Release supports immune system health and reduces the severity and duration of common cold symptoms. It is specially formulated to release a boost of vitamin C over a sustained 8 hour period. The formula is buffered with mineral ascorbates to give you a vitamin C thats gentle on the stomach and has added bioflavonoids thought to support the efficacy of vitamin C. Always read the label. Use only as directed. If symptoms persist talk to your health professional. Supplements may only be of assistance if dietary intake is inadequate.