# Epigenetic Clocks: Can a Test Tell Your Biological Age, and Can Skincare Change It?

> Epigenetic clocks estimate biological age from DNA methylation. How Horvath, PhenoAge and DunedinPACE work, what consumer tests can and can't tell you, and what affects them.

Canonical: https://antiagingcare.org/blog/epigenetic-clocks-biological-age
HTML version: https://antiagingcare.org/blog/epigenetic-clocks-biological-age
Author: Anti Aging Care Editorial Team
Published: 2025-03-01
Updated: 2026-10-24
Category: Science

Epigenetic clocks estimate "biological age" from chemical tags (methyl groups) on DNA that change predictably over a lifetime. The short answer: they are powerful research tools that track age closely and, for newer clocks, predict health outcomes in large studies. But a consumer test gives an estimate with error, results vary between labs and tissues, and no skincare product has been shown to reverse your epigenetic age in a trustworthy trial.

## The short answer

- The first multi-tissue clock (Horvath, 2013) used methylation at 353 DNA sites to estimate age across many tissues and cell types ([Horvath, *Genome Biol*, 2013](https://pubmed.ncbi.nlm.nih.gov/24138928/)).
- Second-generation clocks such as DNAm PhenoAge were trained on health markers and predicted mortality and disease better than chronological age ([Levine et al., *Aging*, 2018](https://pubmed.ncbi.nlm.nih.gov/29676998/)).
- Clocks are increasingly used as outcomes in diet and lifestyle studies, for example twin studies of dietary patterns ([Nygaard et al., *GeroScience*, 2026](https://pubmed.ncbi.nlm.nih.gov/42791452/)).

## How the clocks differ

| Clock | Trained on | Best use |
|---|---|---|
| Horvath (2013) | Chronological age, many tissues | Research age estimates |
| PhenoAge (2018) | Blood markers of health | Risk of disease and death |
| Pace-of-aging clocks | Rate of change over years | Tracking speed of aging |

## What consumer tests can and can't tell you

- They estimate, they don't measure, biological age. Results can differ when the same sample is run twice or on another clock.
- Saliva, blood and cheek samples can give different numbers.
- A single result is a snapshot, so don't overreact to a high or low score.

## What is linked to epigenetic age

Observational studies link faster epigenetic aging to smoking, obesity, poor sleep, chronic stress and low physical activity. These associations don't prove that changing one habit will lower your score, but the same habits improve health anyway. For skin, the biggest controllable driver of visible aging remains UV exposure ([photoaging vs chronological aging](/blog/photoaging-vs-chronological-aging)).

## Can skincare change your epigenetic age?

Some brands claim their products "reverse epigenetic age." Treat these claims with caution unless the brand publishes a randomized, controlled trial with a pre-registered clock and independent analysis. As of this writing, we have not found such evidence for a topical product. For proven skin-aging steps, see our [anti-aging timeline by decade](/blog/anti-aging-milestones-timeline).

## How to read a consumer epigenetic test

1. **Check which clock was used.** Reports may use a proprietary clock without published validation.
2. **Look for a margin of error.** A result of "3 years younger" may be within the test's normal variation.
3. **Retest under the same conditions** (same company, sample type and time of day) if you track change over time.
4. **Don't change medications or treatments** based on the result; discuss health questions with your doctor.

## Frequently asked questions

### Are epigenetic tests worth buying?

They're interesting, but they aren't diagnostic and shouldn't guide medical decisions alone.

### Can I lower my epigenetic age?

Some small trials report changes after diet or lifestyle programs, but results need replication in larger studies.

### Is biological age the same as skin age?

No. Skin aging depends heavily on sun exposure, which a blood clock doesn't capture.

## Bottom line

Epigenetic clocks are a major research advance, but consumer results are estimates. Focus on proven habits (not smoking, sleep, exercise, sun protection) rather than chasing a number.

_This article is for educational purposes only and is not medical advice. Talk to your doctor or dermatologist about your situation._

## Sources

- Horvath S. DNA methylation age of human tissues and cell types. *Genome Biol*. 2013. [PubMed](https://pubmed.ncbi.nlm.nih.gov/24138928/)
- Levine ME et al. An epigenetic biomarker of aging for lifespan and healthspan. *Aging (Albany NY)*. 2018. [PubMed](https://pubmed.ncbi.nlm.nih.gov/29676998/)
- Nygaard M et al. Dietary pattern and epigenetic aging: a longitudinal twin study. *GeroScience*. 2026. [PubMed](https://pubmed.ncbi.nlm.nih.gov/42791452/)