Does NAD+ Actually Work For Anti-Ageing?

NAD+, or, to give it its full name, nicotinamide adenine dinucleotide, is having a bit of a moment.

“I’m gonna NAD+ for the rest of my life and I’m never gonna age,” Hailey Bieber shared on a previous episode of Keeping Up With The Kardashians. Jennifer Aniston is reportedly also a fan of IV NAD+ treatments.

Since then, NAD+ has made its way to social media stardom, with one viral video suggesting it can “address all those signs of premature ageing like jowls, hooded eyes and crows feet”. Boots says search for the term is growing.

But what is NAD+, does it really work, how much should you take, and is it right for everyone?

We asked senior clinician and GP at The Independent Pharmacy, Dr Donald Grant, to share his thoughts.

“NAD (Nicotinamide Adenine Dinucleotide) is a vital coenzyme found in every living cell, crucial for converting food into energy, repairing DNA, and maintaining cellular health,” Dr Grant said.

NAD levels decrease with age. Because NAD plays a big part in cell metabolism and is involved with enzymes that might affect ageing, a 2021 paper said that some think “interventions that increase NAD+ may slow aspects of the ageing trajectory”.

They suggested that replacing or boosting people’s NAD+ levels might lead to them looking younger and feeling healthier.

A mouse study suggested NAD+ could make sleep more efficient. And it may reduce inflammation in mice, too. But a 2026 review of rodent and human studies found “evidence for clinically meaningful anti-ageing or wellness benefits remains heterogeneous and inconclusive across outcome domains”.

Research so far has mostly involved animal trials or small, early-stage human trials.

“While supplements can be utilised to increase NAD+ levels in the human body, there is currently limited evidence that they provide significant anti-ageing, energy, or health benefits,” Dr Grant said.

“Some studies have indicated slight benefits for sleep quality and ageing. However, with research in its early stages, it’s much too soon to draw proper conclusions about the supplement’s effectiveness.”

“There is no widely used test to determine whether an individual ‘needs’ to take NAD+ supplements. Most people take these supplements without a confirmed deficiency,” Dr Grant said.

“NAD+ levels can decline with age or with specific health conditions, such as chronic inflammation and obesity.”

Taking too much NAD+ in supplement form may lead to nausea, headaches, skin irritation, and muscle cramps, said the Cleveland Clinic.

“Pregnant and breastfeeding women should avoid these supplements. It’s also recommended that people with cancer should not take NAD+, as NAD⁺ is involved in cellular growth and repair, and there are concerns that increasing its levels could also support the growth of cancer cells,” Dr Grant added.

“As research is still ongoing, there is no universally accepted ‘best dose’. In clinical studies, people typically took around 250–500 mg per day, but this increased in some cases,” said the GP.

“For people who’d like to take the supplement, I recommend starting on a low dose and opting for reputable brands with clearly listed ingredients to guarantee safety”

He ended, “Overall, while NAD⁺ supplements can increase NAD⁺ levels in the body, it is not yet clear what dose, if any, translates into meaningful health benefits, so a cautious and informed approach is recommended.”