When Stress Is Good For You

The Hormesis Effect

If the world really had a supervillain, it would have to be stress. With all due respect to Thanos, The Joker, and Superman's archnemesis, Lex Luthor, none of these theatrical bad guys hold a candle to the daily villainy we suffer at the hands of stress.

Hormesis and Stress

In the 16th century, the Swiss chemist and scientist, Paracelsus, summarized results from his experiments into his since immortalized expression: "The dose makes the poison." What Paracelsus meant, on one hand, is that even deadly toxins become dangerous to our bodies only in certain quantities. However, he also meant that even "healthy" substances such as oxygen and water also become dangerous in amounts either inadequate or excessive. The dose—in the form of amount, duration, or intensity—determines the healthful or harmful effect of a substance on us, not the substance itself (1). Yet what even Paracelsus himself didn't imagine at the time is how his proverb about chemical stress would eventually prove equally true about physical and emotional stress.

Paracelsus was referring to an anciently recognized (Roman emperors who supposedly employed hormesis techniques to inoculate themselves against assassination attempts by ingesting small doses of certain poisons. The same process allows modern drinkers to develop a tolerance to alcohol) biological process called hormesis(2). Technically, hormesis refers to a common biochemical pattern where a substance (vitamins or medicines) shows a beneficial effect at certain doses but negative effects at higher or lower doses (too much or too little iron, potassium, or vitamin A can be deadly).

  • The hormesis process explains why sunlight can give you a tan or give you skin cancer.
  • Why exercise can put you in the hospital or put you in the Olympics.
  • Why cold water exposure can cause hypothermia or cure depressive symptoms.
  • Why starvation will kill us while intermittent fasting produces many health benefits.
  • Why nutrition quality can predispose metabolic diseases or promote optimal health.

On the other end of the spectrum, appreciate that the most skilled, strong, fit, and prosperous people in the world didn't acquire their abilities overnight or through inborn talent alone. They acquired them in large part through hormesis; a systematic process of progressive stress exposure that gradually produced remarkable results. Each of us possesses this hormetic potential. It is coded right into your DNA, among the greatest gifts of our ancestors. Yet benefiting from hormesis requires that we abandon the prevailing cultural meme that stress is uniformly bad for us or needs to be eliminated.


If you want an easy way to understand and apply hormesis to your life, remember the story of Goldilocks and the Three Bears. Just like porridge, stress can be either too hot or too cold. Yet stress can be a great source of satisfaction when the temperature is just right.


1. Calabrese EJ. Hormesis: Path and Progression to Significance. Int J Mol Sci. 2018 Sep 21;19(10):2871. doi: 10.3390/ijms19102871.

2. Mattson MP. Hormesis defined. Ageing Res Rev. 2008 Jan;7(1):1-7. doi: 10.1016/j.arr.2007.08.007. Epub 2007 Dec 5.

3. Stavnichuk, M., Mikolajewicz, N., Corlett, T. et al. A systematic review and meta-analysis of bone loss in space travelers. npj Microgravity 6, 13 (2020). https://doi.org/10.1038/s41526-020-0103-2