One of the main concerns with supplements is that they don’t always make it into the bloodstream, but are instead broken down by the digestive system. This is the case with collagen supplements – despite being touted as a brilliant way to increase levels of collagen in the skin, when ingested the compound is actually broken down into amino acids and directed to wherever the body needs it.

That doesn’t seem to be the case with NAD+. A 2021 paper, published in the Translational Medicine of Aging, found that oral supplementation of 500mg of nicotinamide led to a significant increase in blood NAD+. However, 100mg of the supplement and a control group taking no supplement had no increase in NAD+ in the body. For that reason, the compound might be more beneficial than other compounds that promise increased muscle and age-proofed skin.

NAD+ supplements are said to increase longevity, improve skin health and boost muscle mass – but what do the experts think?