Margaret, 58, from Harrogate, described it to us the way hundreds of readers have: she wakes feeling reasonably well, gets through the morning — and then, somewhere around three o’clock, a fog rolls in. “It’s not that I’m ill,” she said. “It’s that I feel switched off. The energy I used to take for granted just isn’t there.”

If that sounds familiar, you are in very good company. The afternoon slump, the second cup of coffee that no longer works, the sense that recovery takes longer than it once did — these are among the most common complaints reported by adults over 40. For years, the standard advice was simply to sleep more, move more and worry less. Sensible enough. But researchers studying how we age have become increasingly interested in something more fundamental: what is actually happening inside our cells.

The answer, it turns out, may come down to a molecule most people have never heard of.

Why energy quietly declines after 40

Every cell in your body runs tiny power plants called mitochondria. They take the food you eat and the oxygen you breathe and convert them into a usable form of energy. When those power plants run efficiently, you feel it: steady stamina, clear thinking, quicker recovery. When they slow, you feel that too — as fatigue, sluggishness and that all-too-familiar mid-afternoon dip.

Ageing affects this system in ways that are gradual and easy to miss. We rarely notice a single dramatic drop. Instead, most people describe a slow drift — the growing sense that the body simply doesn’t bounce back the way it used to.

So what exactly is NAD+?

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every living cell. Think of it as the currency your mitochondria use to keep the lights on. It plays a central role in converting nutrients into energy, and it supports hundreds of essential reactions — including processes involved in cellular repair and maintenance.

The catch is that NAD+ isn’t static. It is used up constantly, and our natural ability to top it up appears to decline with age. That gap — between what our cells demand and what we can readily supply — is exactly what researchers in the field of healthy ageing are working to understand.

“We can’t stop time. But the science increasingly suggests that supporting the cellular machinery behind our energy is one of the more sensible things we can do as we age.”

The problem with most supplements: absorption

Here is where things get interesting — and where many products fall short. Simply swallowing a compound doesn’t guarantee your body can use it. Many nutrients are fragile. They can be broken down in the digestive tract long before they reach the cells that need them. In practice, a large share of what you pay for may never make it where it matters.

This is why formulation scientists have turned to a technique called liposomal delivery. A liposome is a microscopic protective bubble, made from the same kind of fatty material as your own cell membranes. It wraps around the active ingredient, helping shield it on its journey and supporting better absorption. It’s the difference between posting a fragile parcel loose in a sack — and packing it properly first.

A quiet favourite among readers: MYSIA Liposomal NAD+

Among the products our readers have asked about most is MYSIA Liposomal NAD+ with Resveratrol — a British-formulated supplement built around exactly this idea of protected, better-absorbed delivery. Each capsule pairs a high-strength 550 mg dose with trans-resveratrol, a plant compound found in red grapes that is often studied alongside NAD+ for its complementary role in cellular health.

It’s worth being clear about what a supplement like this is — and isn’t. It is not a medicine, a miracle or a substitute for looking after yourself. It is a considered, third-party-tested formulation designed to support your body’s own cellular energy processes, taken alongside good sleep, sensible movement and a balanced diet.

How to take it

The typical approach is two capsules daily with water, ideally with a meal. Because it’s a food supplement rather than a stimulant, there’s no jolt and no crash — the aim is steady, everyday support rather than a quick hit.

Who it’s for

It’s aimed squarely at adults over 40 who want to stay active, sharp and independent — and who prefer a measured, evidence-informed approach over hype. If you are pregnant, breastfeeding, taking prescription medication or managing a health condition, speak to your GP or pharmacist before starting any new supplement.

What to expect, and when

Supplements are not overnight fixes, and anyone who tells you otherwise should be treated with caution. Most people take a consistent daily dose and give it time. Below is the sort of timeline readers commonly describe — individual experiences vary, and this is not a promise of results.

What readers are saying

The following are illustrative testimonials provided for the purposes of this article. Individual results vary.

Common questions