A plethora of longevity-based companies are offering biological age tests—which may reveal more about the future of our health than the number we celebrate annually. Using epigenetic markers, many biological age tests measure the impact of lifestyle, environment, and behavior on aging. With more awareness of the role people play in how fast they’re aging, they can adjust their diet, exercise, social connectedness, and sleep. 

“Aging is not something that is set in stone like a train going on a track,” says Irina Conboy, Ph.D., a longevity researcher from UC Berkeley who has studied in the field for over two decades. “People will realize that there could be something meaningfully done about it. The overarching goal is to delay or perhaps reverse or even prevent diseases that rob people of their quality of life and independence.”

Today, Generation Lab, a biomedical research company cofounded by Conboy, is getting in on the aging game by launching its test. With a wait-list of over 1,000 people, Generation Lab’s new at-home molecular aging test requires a cheek swab to analyze an individual’s risk for top health conditions and the pace of aging across 19 systems in the body.

“Our focus is to provide a clear result to making you biologically younger,” cofounder Alina Su, who has studied longevity at Harvard Medical School and Berkeley, tells Fortune in an exclusive interview ahead of the launch. “We’re trying to be the center of the measurement to actually guide people on their way to longevity.” 

Like other tests in the industry, Su’s team offers a basic membership, which includes three tests a year, for about $400. Premium membership offers the first test at $399 and subsequent tests at $139 per month for six tests per year. After an initial test, members are paired with a physician at clinics primarily located in New York and California to develop a personalized health plan to mitigate the risks and take subsequent tests to evaluate the interventions. 

Aging researchers have voiced concern about the hefty price tag for these tests, which makes them inaccessible to most Americans. Scientists are also concerned about the accuracy of the results. 

Dr. Andrea Maier, director of the Centre for Healthy Longevity at the National University of Singapore and founder of Chi Longevity and the Healthy Longevity Society, previously told Fortune that thousands of biological age tests on the market “differ in validity.” While she says epigenetic age tests are the most accurate, the industry itself is new, and there are no standard guidelines across the board for how these tests work and what they measure. Dr. Florence Comite, an endocrinologist and founder of the Comite Center for Precision Medicine & Health, encourages eager users to look beyond marketing hype and assess how the data is derived when making a decision about which test to try. She also says the tests are most effective when paired with actionable steps from a licensed physician to help motivate people to alter particular lifestyle choices.

Major players including Tally Health and TruDiagnostic, which offer epigenetic age tests, have also acquired thousands of eager participants. For Generation Lab, the founders say their test doesn’t rely on mathematical modeling but on “molecular biological noise” from the individual.  

What is biological noise? 

Think of biological noise in relation to a car’s operating system, Conboy says. Like a car, many systems are needed for the body to perform. For example, if engine fuel is low, you get an alert on your dashboard. Within the body’s blueprint, noise can signal an early deterioration of cells and indicate the risk of Alzheimer’s disease, diabetes, and obesity, for example. Measuring biological noise helps people see the body’s cellular damage and where interventions may target the pace of aging more dramatically. 

“We are measuring the noise in the human body, and what is happening is that even before there is actual manifestation of disease before people feel very sick, the body is sending these alarm signals through these little molecules,” Conboy says, adding the test was created from six human studies. “We, therefore, can detect that something’s wrong before there is a really serious problem.”

With the test’s results, a physician at a partnering clinic can then indicate which interventions may be impactful. 

“As we’re aging, our DNA expression will be more and more noisy as well,” Su says, whose aim is to target where the noise is, which can affect the function of cells and propel aging. Some 5,000 interventions are available once doctors know where the noise is, Su says. She hopes over time, other researchers can use the data from their participants to see the efficacy of certain interventions to reduce the risk of conditions compared to others.

With a personalized approach, Conboy hopes Generation Lab guides people “away from the dangers of pseudo longevity” and the inclination to take supplements or try diagnostics without much knowledge of whether they are right for them. 

“I don’t want our field to shoot ourselves in the foot by trying to pander something that there’s no trade in,” Conboy says. 

The growing craze to be biologically younger 

The over $26 billion longevity industry is capitalizing on people’s interest in slowing aging, optimizing their health, and achieving an operating system comparable to someone much younger than their chronological age. Longevity guru and former Silicon Valley executive Bryan Johnson shares how he has slowed his pace of aging by 31 years and has the VO2 max capacity in the top 1.5% of 18-year-olds, according to his publicly available tests.

Other voices in the space include David Sinclair, who says he’s biologically a decade younger, and Dr. Mark Hyman, who regularly shares his tips for slowing down the pace of aging. Peter Diamandis, founder of XPRIZE, recently launched a $101 million competition for teams who can develop therapies to restore a decade of life. Still, the field is new, and experts recommend engaging with interventions and tests thoughtfully and with caution, for those who are interested. 

“The reasonable idea of working for a good health span becomes replaced by a competitive drive to be younger biologically by any and all means, and to test and monitor the body constantly,” Elissa Epel, Ph.D, codirector of the Aging, Metabolism, and Emotions Center at the University of California, San Francisco and author of The Stress Prescription, tells Fortune in a written response.