Forget Ozempic — an under-the-radar antiaging supplement is the next hot commodity in Hollywood

• NAD is a critical part of being human. It helps our cells function properly.

• But as we age, our ability to produce NAD declines.

• Celebrities are using NAD+ boosters to try to stay young and healthy.

"I'm going to NAD for the rest of my life, and I'm never going to age," Hailey Bieber said jokingly as she waited for an IV of yellowy liquid to drip into her veins.

She was talking about NAD+ boosters — the antiaging elixirs that have joined the ranks of Ozempic and Botox as staples of elite wellness routines.

The Kardashians inject them through IVs, and Joe Rogan swears by them for his immunity. Even the military is testing out NAD boosters, hoping they may someday rejuvenate soldiers on the battlefield.

It's much like how Hollywood jumped on the Ozempic craze a few years ago. Before drugs such as Wegovy were approved for weight loss, celebrities were dropping inches with weekly off-label injections.

Now, elite biohackers and wellness influencers are leaning hard into trendy NAD-boosting drips, powders, and supplement capsules promising to keep them young, vibrant, and strong, even though the US Food and Drug Administration has technically banned many of these supplements from being sold while they're still being tested clinically.

NAD supplements promise to replenish your body's natural supply of a critical molecule called nicotinamide adenine dinucleotide. It's one major component of healthy bodies.

"NAD coenzymes are the central catalysts of all living things," Charles Brenner, a biochemist who studies NAD, told Business Insider. "They underlie the conversion of protein, fat, and carbohydrate into energy. They underlie the conversion of everything that we eat into everything that we do and everything that we are. They are required for our cells to generate energy."

NAD is life-and-death important. Without the proper vitamins and minerals for creating it, people develop diarrhea, brain issues, red, scaly skin, and eventually waste away and die. With high levels of it, you may feel just a little sharper, more well-rested, and energetic. In short: young.

As we age, our bodies become less efficient at doing many things, including producing NAD. So while your average 20-year-old can generate more than enough NAD from food and activity, most 60- or 70-year-olds may benefit from a booster. Whether it does anything for health influencers, athletes, and wellness buffs in their 30s, 40s, and 50s remains to be seen.

The problem is, many NAD-boosting supplements don't work. You need to know a lot about your chosen product — and yourself — to understand how successful any "boost" will turn out.

There are several different ways to boost NAD — but some of the most popular ones don't work

Nutrition experts have known for nearly a century how important this coenzyme is to our health. It's the reason all-purpose flour and cereal are enriched with niacin, a common NAD precursor.

But it wasn't until the past two decades that a groundbreaking body of research started to emerge showing NAD-boosted mice can not only survive and thrive but can actually live longer with less fat, more musculature, lower inflammation, and fewer age-related issues.

Then, roughly a decade ago, scientists started taking these products out of their labs and developing NAD-boosting companies. That's when NAD boosters really took off with longevity-seekers.

From lab rats to gym rats, boosting your NAD levels is no longer something just for mice in cages. Anyone remotely linked to longevity innovation is at least thinking about trying this out.

"You have in this industry billionaires, biohackers, brilliant scientists from the best schools, but you also have athletes and beautiful people and people who just generally want to stay young," Robert Fried, a moviemaker-turned-CEO of the NAD supplement company ChromaDex, told BI. (Brenner is ChromaDex's chief science advisor.)

Fried said NAD boosting is generally good "when you want to increase your resiliency" — maybe you're jet-lagged, you pulled an all-nighter, or you're feeling just a little bit sick.

To boost NAD, don't take NAD

But if you want to boost your NAD levels, there's no point in taking NAD as a supplement. The NAD molecule is just too big to be taken up by our cells.

"It's pretty useless," Dr. Sabine Donnai, a physician who has been testing out formulations of NAD boosters for her patients at the posh Viavi longevity clinic in London, told BI. She's found, through blood tests, that NAD supplements and IVs don't work much at all.

Independent experts such as Dr. Shin-ichiro Imai, a professor of developmental biology at Washington University School of Medicine in St. Louis who's been studying NAD for decades, agree with Donnai.

"Unfortunately, NAD itself is not as effective as other compounds," he said. "It's big and it cannot actually easily go into cells. And also, if you take NAD orally, your gut bacteria basically consume NAD completely."

That's why most scientists say it's far more effective to take NAD precursors — the stuff that our bodies use to create NAD. That includes nicotinamide riboside, nicotinamide mononucleotide, nicotinic acid, and niacinamide. (For those in the know, that's NR, NMN, niacin, and NAM.)

How to boost your NAD without an IV drip

If a young, healthy person walked into Viavi seeking an NAD+ supplement, Donnai would probably recommend lifestyle tweaks instead of pricey IVs and supplements.

Walking, eating meat and fish, nuts, fortified breakfast cereal, broccoli, and even cucumbers can help to boost your levels — at least a little bit.

"It's not about living the perfect life, but it's about being sensible, rather than just supplementing," Donnai said.

For the clients who could benefit from NAD boosters, she recommends a powder, which they can mix into a morning smoothie. It costs $118 for a one-month supply, and is a combination of NR, NMN, and NAM.

"It's not a quick fix for anything," she said. "The NAD on its own doesn't really do much. It supports the other functions." It's helping our bodies run properly, by supporting energy metabolism, keeping DNA in good repair, and regulating bone density, among other key activities.

Donnai said that even with a daily supplement-powder regimen, about 10% to 15% of clients didn't end up getting any NAD boost, and their bloodwork showed it. Experts aren't yet sure exactly what's driving that non-response in some patients.

We're still at the beginning of research on NAD boosting

NAD+ is booming in popularity.

In London, Sonnai's longevity clinic serves wealthy clients who want to maximize their longevity or improve ailing health. She estimates that about 30% of them may be recommended some kind of NAD-boosting regimen at some point.

While she believes it can help rejuvenate patients with aging-related diseases or other illnesses, she worries people who don't actually need any supplemental NAD could overdo it. We don't know what kinds of problems that may cause.

"I would personally never advise anybody to take anything at all until you've measured whether you actually need it," she said.

Dr. Shalender Bhasin, who is conducting some of the biggest ongoing clinical trials of NAD boosters at Brigham and Women's Hospital in Boston, said research so far had tested compounds such as NMN on only a few hundred people.

"I would say they're relatively safe at the doses that have been used, and they can raise energy levels in the blood and some tissues, but not in all tissues," he said. One that hasn't been reliably boosted yet in humans is muscle.

Patients with diabetes, kidney disease, and Alzheimer's are just some of the populations he thinks may be able to benefit from NAD boosting some day.

"We are really early in the first inning," he said.

Correction: An earlier version of this story misstated the title of Professor Charles Brenner at ChromaDex. He is the chief scientific advisor.

Read the original article on Business Insider