Men’s Health: Toxicologists Explain What a Toxin Is—And If They’re Always Harmful
Source: Men's Health
Publication Date: July 11, 2025
Medical Toxicologists: Ziad Kazzi, MD, FACMT; Ryan Marino, MD
Keywords/Topics: Toxicology, toxins, misinformation
Men's Health: Toxicologists Explain What a Toxin Is—And If They’re Always Harmful
On social media, certain influencers love to throw around the word “toxic.” Seed oils are toxic. Oatmeal is toxic. Kale is toxic. But these claims are often false or misleading.
Toxins are a real concern. But anything (even water) can be toxic if you’re exposed to too much of it. So you need nuance to fully understand whether something is potentially toxic and could actually harm you, says Ryan Marino, MD, a medical toxicologist, emergency physician, and associate professor at the Case Western Reserve University School of Medicine in Cleveland, Ohio.
“Anyone using the word “toxin" right off the bat—people should be careful about where it’s going because there’s a ton of misinformation out there,” he says.
Here’s what toxicologists want you to know about toxins, including how they’re measured and how to parse through the misinformation about them.
What exactly is a toxin?
TRADITIONALLY, THE TERM “toxin” refers to a chemical produced by a “living organism,” such as a plant, animal, bacteria, or virus, that’s poisonous, explains Ziad Kazzi, MD, president of the American College of Medical Toxicology’s board of directors. That could include snake venom or certain kinds of mushrooms, for example.
On the other hand, a “toxicant” typically refers to manmade substances, such as forever chemicals or other synthetics, that may be poisonous, he says.
However, regular people (that is, not doctors or scientists) often use “toxin” to encompass both categories, and Dr. Kazzi says that’s usually OK for general discussions.