Primary Antioxidants Explained: How SOD Works Differently Than Vitamin C and Glutathione

3 minutes
Emma Belanger
Primary Antioxidants Explained: How SOD Works Differently Than Vitamin C and Glutathione

Not All Antioxidants Are Equal Meet the Team Your Body Builds Itself

JuLY 24, 2026

Did you know our bodies make their own antioxidant enzymes? Yep — that's right. Our body makes three antioxidant enzymes, and I want you to meet the team of three.

Know the lingo

Endogenous vs. exogenous, primary vs. secondary — decoded

Before we meet the team, let's decode the words you're about to see everywhere in this post:

Endogenous
Made inside your body
Produced internally, by your own cells — this is exactly what taking SOD signals your body to make more of.
Exogenous
Comes from outside your body
Sourced from food, drinks, or supplements — not self-made.
Primary antioxidant
An antioxidant enzyme
One of only 3: SOD, catalase, glutathione peroxidase. Endogenous by definition.
Secondary antioxidant
Everything else
Vitamin C, vitamin E, glutathione, polyphenols — mostly exogenous, from food.

What is a primary antioxidant?

Our body makes three antioxidant enzymes entirely on its own:

  • SOD
  • Catalase
  • And Glutathione Peroxidase

These antioxidant enzymes are known as primary antioxidants, because our body makes them on its own.

Quick recap — primary antioxidants:

  • Are endogenous antioxidants — made entirely by your own body
  • Are antioxidant enzymes, not vitamins or minerals
  • There are only 3: SOD, catalase, and glutathione peroxidase
  • Work as catalytic antioxidants — reused again and again
SOD CAT & GPx Glutathione, CoQ10 Carotenoids, Flavonoids Vitamins C, A, E Minerals Primary Antioxidants Made by our own body Secondary Antioxidants Only from food
Source: our SOD supplier, Bionov — bionov.fr/en/sod-b/primary-antioxidants/

What is a secondary antioxidant?

All other "antioxidants" — like vitamin C, vitamin E, glutathione (this is different than glutathione peroxidase, the enzyme our body produces), tart cherry, blueberry, pomegranate, and more — our body does not make these antioxidants. These antioxidants are known as secondary antioxidants.

Quick recap — secondary antioxidants:

  • Are exogenous antioxidants — sourced from food, not made by your body
  • Include vitamin C, vitamin E, glutathione, and polyphenols like tart cherry, blueberry, and pomegranate
  • Are still real, valuable antioxidants — just a different category

Glutathione vs. glutathione peroxidase: what's the difference?

This is the mix-up worth clearing up. Glutathione is a molecule — a secondary antioxidant, built from three amino acids. Glutathione peroxidase (GPx) is completely different: it's the enzyme, one of our three primary antioxidants, and it uses glutathione as fuel to do its job.

Secondary antioxidant
Glutathione
The molecule. Exogenous and endogenous sources exist, but it works like a secondary antioxidant — used once, then spent.
Primary antioxidant
Glutathione Peroxidase (GPx)
The enzyme. Endogenous, made by your body, reused endlessly, runs on glutathione as fuel.

Primary and secondary are different — not "better" or "worse"

Primary and secondary antioxidants are not equal, and they do not work the same. But I am not here to tell you that:

  • SOD is better than glutathione, or that glutathione as a supplement doesn't matter
  • SOD is better than tart cherry, or that tart cherry doesn't matter
  • SOD is better than vitamin C, or that vitamin C doesn't matter

What I am here to tell you is that they do not work the same — primary and secondary antioxidants are not the same, and they are not equal. They have much different capacities to stop damage from happening, and where they stop that damage: whether they're stopping it at the source, or cleaning it up after it's already happening.

Primary antioxidants stop damage early, right at the source. Secondary antioxidants are the cleanup crew for whatever's left.

So how does taking an SOD supplement actually work?

Taking SOD sends a signal to our bodies to make more of all three of its own antioxidant enzymes — SOD, catalase, and glutathione peroxidase.

"The most valuable antioxidants aren't the ones you eat — they're the ones your own body produces."

— as our SOD supplier's research puts it
From Emma's routine

That's why I take SOD — every. single. day. Not instead of everything else — my vitamin C, my polyphenols, my secondary antioxidants still matter, and I still use them. But SOD works upstream, right at the source, before there's anything to clean up. It's the first domino. I want that foundation covered before anything else gets to work — that's the whole reason SOD is non-negotiable in my own routine.

Primary and secondary antioxidants aren't working against each other — we need them both. Next up: how all three primary antioxidants work together, like a relay team, and why primary antioxidants can neutralize over a million free radicals each. Stay tuned.

References

  1. Wang Y, Branicky R, Noë A, Hekimi S. Superoxide dismutases: Dual roles in controlling ROS damage and regulating ROS signaling. J Cell Biol. 2018;217(6):1915-1928. PMID: 29669742
  2. First line defence antioxidants — SOD, CAT, GPX: Their fundamental role in the entire antioxidant defence grid. Saudi J Biol Sci. sciencedirect.com/science/article/pii/S2090506817301550
  3. Carillon J, Rouanet JM, Cristol JP, Brion R. Superoxide Dismutase Administration, A Potential Therapy Against Oxidative Stress-Related Diseases. Pharm Res. 2013;30(11):2718-2728. PMID: 23793992
  4. Short-term assessment of toxicological aspects, oxidative and inflammatory response to dietary melon superoxide dismutase in rats. Food Chem Toxicol. 2013. sciencedirect.com/science/article/abs/pii/S0278691513000598
  5. Bionov (our SOD supplier), FAQ — bionov.fr/en/faq/, and "Primary Antioxidants" — bionov.fr/en/sod-b/primary-antioxidants/ (source for the pyramid chart and the supplier quote above)