Longevity Biohacks: What Works and What to Skip
You can't stop aging, but plenty of influencers swear they have the secret for staying healthy and vibrant through the decades. Some even say their strategies will stretch your lifespan out to 100 years and beyond. But do any longevity biohacks actually work? We asked experts and scoured the science to figure out which ones make sense—and which you can probably skip.
Biohacks You Should Skip
Cold Plunges
What is it: Immersing yourself into an ice-cold bath (generally between 50 and 59°F) for around five minutes. Many athletes plunge after a game or workout to soothe sore muscles.
What does it do: The idea behind the plunge is that the shock of the extreme temperature creates a strong physiological response in the body. "It triggers a big adrenaline and norepinephrine response, which is probably why people feel so good afterward," says Jay Luthar, M.D., an integrative primary care physician and instructor of medicine at Harvard Medical School. Science has shown that there are some benefits to the freeze: Cold-plunging may activate brown fat (which burns glucose and other fat molecules) and improve some metabolic factors, Dr. Luthar says. One meta-analysis published in 2025 found some improvements in sleep, stress, and immunity from this frigid practice, but there is no solid evidence that it has any effect on longevity. And the meta-analysis even points out the need for stronger research involving more people to back up any benefit.
Instead of prolonging your life, there is a chance that freezing water can shorten it: The American Heart Association points out that immersion in cold water is dangerous for people with heart conditions (including undiagnosed ones), as rapidly restricting blood vessels makes the heart beat faster and the shock of the extreme cold can cause hyperventilation.
Verdict: If it feels good after a workout, go for it, but that doesn't mean it will help you live longer.
Taking NAD+ IV Infusions
What is it: It seems like infusion bars are popping up faster than coffee bars in many cities; you may have seen the buzz that getting nicotinamide adenine dinucleotide (NAD+) dripped into your veins will give you the edge on mortality.
What does it do: Dubbed the "fountain of youth" in the wellness world, NAD+ is touted for its potential benefits for sleep, skin, mental clarity, recovery, and energy production. NAD+ is a naturally occurring molecule that helps our cells stay healthy and our mitochondria produce energy. It also decreases as we age.
But most of the studies on NAD+ have been done on animals, and there's not enough data to apply any of those findings to human longevity. Plus, it's important to note that none of the NAD+ forms available, including oral supplements, injections, and IV infusions, have been approved by the Food and Drug Administration (FDA). Not to mention, they can cause side effects, including chills, diarrhea, shaking, and vomiting.
Instead of spending several hundred dollars at an infusion bar, Dr. Luthar recommends hitting the gym. "The most reliable way we know how to raise NAD+ in human muscle is exercise," he says.
Verdict: Skip it.
Injecting Peptides
What is it: Social media is swimming with wellness influencers claiming that peptides are the wonder drug to stop aging. But many of these have not been tested or approved by the FDA.
What does it do: Peptides are short-chain amino acids that occur naturally in the body, but the ones you find for sale online or in your corner supplement store are synthetic copies. (Peptides are also a popular ingredient in skin care, claiming to help firm, smooth, and nourish skin.)
There are many peptides that have been studied for years, approved by the FDA, and available by prescription, including insulin and GLP-1 medications, such as Ozempic and Mounjaro. However, many of the injectable wellness supplements that are promoted online and by some governmental "health experts" with a big megaphone haven't been FDA-approved, haven't been rigorously studied in humans, and are sold by unregulated manufacturers.
"There are a lot of anecdotes and very little science [on peptides]," says Jeffrey Bland, Ph.D., a biochemistry and nutrition researcher and author of the upcoming book, The Nourished Gene. The biggest risk of peptides is the sourcing, Dr. Luthar says, as it's hard to know which manufacturers are testing for potency, sterility, and contaminants. "For something you're injecting, that's not a small thing," he says.
In fact, two women who received peptide injections at a wellness fair nearly died from the experience, according to a report in ProPublica.
Verdict: While peptides do have benefits, talk to your doctor about how to take them safely, and skip anything that is not approved or tested.
Biohacks That Actually Work
Mix Cardio and Strength
What is it: This is all about working out the old-fashioned way, with a mix of aerobic exercise and strength training.
What does it do: "Aerobic fitness is one of the strongest predictors of how long you live, stronger than most of the risk factors we treat with medication," Dr. Luthar says. This can include anything that gets the heart pumping and your blood flowing, including walking briskly, swimming, riding a bike, or dancing.
As for how much you need, the American Heart Association recommends you do at least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous aerobic activity per week.
Strength training is equally important. Research shows that maintaining muscle mass helps support metabolic health, bone density, and overall function—all key components of healthy aging.
Verdict: This is the real longevity secret. Consistently combining cardio and strength training is one of the most reliable ways to extend your healthspan.
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