There are many acronyms you might find on the packaging of so-called longevity supplements, promoted by influencers for their ability to “repair DNA” and assist in “anti-ageing”.

NRC (nicotinamide riboside chloride) and NMN (nicotinamide mononucleotide) are two of them – both precursors or “building blocks” for NAD (nicotinamide adenine dinucleotide), a naturally occurring molecule in the body. Trimethylglycine (TMG) is another and is sometimes added to “support” other ingredients.

Packaged together, these ingredients are supposed to “boost daily vitality” and “improve cellular health”, according to their promoters.

But is there any evidence to support these claims?

While some longevity supplements contain multiple ingredients in one tablet, others promote “stacking” – that is, buying different products and ingredients and taking them together for an optimum longevity boost.

Prof Oliver Jones, an internationally recognised expert in analytical science with RMIT University, says NAD is involved in many chemical reactions in the body, including energy production and DNA repair.

“Your body has two main ways to get NAD,” he says.

“It can create it from scratch … or it can........

© The Guardian