Thorne's Biological Age calculates an estimation of biological age-- or internal age, as opposed to one's chronological age based on birthday. It requires a set of blood biomarkers that are used extensively in the health-care system. 

Physicians rely on blood biomarkers to assess an individual's risks for developing diabetes, heart disease, liver disease, immune deficiencies, and more. The blood biomarkers use for Biological Age are statistically relevant to one's health. They represent impactful biomarkers used by the medical community to assess a person's general health. Physicians trust blood biomarkers because they are relatively consistent across populations and labs, have well-understood meanings regarding the systems they reflect and provide crucial insight for guiding their patients' treatment. 

Clinical lab measures are robust, interpretable, and directly reflect your current health, and they are conveniently available from a single blood draw. For these reasons, Biological Age's blood biomarkers are reliable to use to interpret one's biological age and provide actionable advice to improve that is relevant to your health.

For a given individual, Thorne's Biological Age Test can address questions such as: Is my body aging faster than my chronological age? Which system or organ should I be paying the closest attention to? How does my rate of aging compare to other adults? Your age results then guide the recommendations designed to optimize your wellness, minimize your biological age, and reduce your risk for common chronic disease conditions as reflected in the clinically validated measures. Personalized actionability is at the crux of the Biological Age test.  

Thorne's Biological Age test is not intended to diagnose, treat, or prevent any disease.  Always consult with your health-care practitioner about concerns regarding a medical condition.

Other Biological Age Estimators 

Several other excellent predictors of biological age exist and most commonly analyze telomere length and DNA methylation.  While these can be useful, they are not without their challenges. 

Telomere length tends to decrease as humans age, but this does not necessarily imply that actively increasing telomere length would increase lifespan.1 Telomere length is likely a mechanism of replicative aging that limits the number of times a cell replicates, which is quite advantageous if you are interested in preventing the spread of cancer. This is an important trade-off that humans evolved to make: trading senescence (the process of deterioration with age) for reduced cancer risk. 

Additionally, it is unclear how one would increase telomere length in vivo. Any treatments along these lines would likely require drugs, stem-cell transplants, or gene therapies that are at this point both expensive and unproven.

Similarly, while cellular senescence is widely viewed as a key process in aging, it does not address other "hallmarks of aging" such as genomic instability, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, stem cell exhaustion, and altered intercellular communication.2

The second commercial estimator of biological age is DNA methylation (DNAm).3 DNAm focuses on a different hallmark than telomeres, epigenetic alterations. "Epigenetic clocks" have excellent predictive power, on par with our Biological Age test, and thus are a good measure of biological age.  However, they tell little about how an individual can optimize their own wellness and do not allow for actionable recommendations the way a test based on validated and interpretable clinical labs does.

One small study has shown that combined administration of Growth Hormone, Metformin, and DHEA can reverse an individual's 'epigenetic clock,` but whether that reversal is overall beneficial to an individual's wellness is very controversial.4 There are significant safety concerns about widely administering anti-aging hormonal therapies.5  

It is through the study of multi-omic measures and whole biological systems that our Biological Age test, powered by Onegevity's Health Intelligence, has come about. Its convenient, repeatable, reliable, actionable, and personalized—and is being used worldwide to help individuals understand how fast their internal clock is ticking.

How is biological age calculated with Thorne's Biological Age test?

Biological Age uses the Klemera-Doubal (KD) algorithm, a theoretically optimal method of calculating biological age using linear biomarkers of aging.6 It has been shown more effective at predicting all-cause mortality than chronological age, as well as reflecting in physical capability, cognitive decline, self-reported health, and physical appearance in midlife.7-8

Biological age calculation using blood biomarkers and the KD algorithm has been shown to be effective at quantifying wellness. Research has shown chronic disease conditions generally reflected in higher biological ages relative to chronological age, and most importantly was modifiable through the application of healthy lifestyle changes. Thorne's Biological Age test is based on this algorithm over other methods for several reasons:

  1. Opaque machine learning techniques, such as Deep Nets, may provide a more accurate prediction of chronological age, but their opaqueness reduces the model's explainability and prevents personalized actionability.
  2. We found in using interpretable regression-based techniques (Lasso, Elastic-net, Robust Regression) that bias was introduced. It resulted in younger adults generally appearing older than they are, and more senior adults generally appeared younger than they were. When attempting to quantify wellness relative to aging, consistently identifying the young as less well and the elderly as more well is not a desirable property.

The KD algorithm we use provides consistently unbiased results across the human lifespan.

Thorne's Biological Age Test: Transforming the Way We Age

Thorne's Biological Age scores are derived from the observations of thousands of men and women. Just as men and women have different expected lifespans and various health concerns, Biological Age uses different models to predict biological age for each sex. 

Your biological age outcome is a combination of metabolic, immunologic, hematologic, hormonal, and organ health into a single score that represents a holistic picture of your wellness. Additionally, you receive five subscores: Blood Age, Metabolic Age, Lipid Age, Kidney Age, and Liver Age. This allows individuals to focus on improving systems or organs that are most relevant to their health. Each contains actionable possibilities that will, in turn, alter one's central Biological Age.

Discover how your lifestyle has affected you and transform the way you age with knowledge from Thorne's Biological Age test.

Get started today: Thorne's Biological Age Test requires you to complete a Health Profile inside your Thorne account and get a fasted blood draw at your local lab. Results appear in your Thorne account in 5-7 days with complete insights and personalized recommendations to optimize your health and slow your aging progression. 


  1. Simons, Mirre JP. "Questioning causal involvement of telomeres in aging." Ageing research reviews 24 (2015): 191-196.
  2. López-Otín, Carlos, et al. "The hallmarks of aging." Cell 153.6 (2013): 1194-1217.
  3. Horvath, Steve. "DNA methylation age of human tissues and cell types." Genome biology 14.10 (2013): 3156.
  4. Fahy, Gregory M., et al. "Reversal of epigenetic aging and immunosenescent trends in humans." Aging cell 18.6 (2019): e13028.
  5. Anderson, Lindsey J., Jamie M. Tamayose, and Jose M. Garcia. "Use of growth hormone, IGF-I, and insulin for anabolic purpose: pharmacological basis, methods of detection, and adverse effects." Molecular and cellular endocrinology 464 (2018): 65-74.
  6. Klemera, Petr, and Stanislav Doubal. "A new approach to the concept and computation of biological age." Mechanisms of ageing and development 127.3 (2006): 240-248.
  7. Levine, Morgan E. "Modeling the rate of senescence: can estimated biological age predict mortality more accurately than chronological age?." Journals of Gerontology Series A: Biomedical Sciences and Medical Sciences 68.6 (2013): 667-674.
  8. Belsky, Daniel W., et al. "Quantification of biological aging in young adults." Proceedings of the National Academy of Sciences 112.30 (2015): E4104-E4110.
  9. Earls, John C., et al. "Multi-omic biological age estimation and its correlation with wellness and disease phenotypes: a longitudinal study of 3,558 individuals." The Journals of Gerontology: Series A 74.Supplement_1 (2019): S52-S60.