Coenzyme Q10 and the NQO1 gene

Most people who buy Q10 never hear the one fact that decides whether it will work for them: Q10 has to be switched on inside the body before it can do anything. The gene that does the switching is NQO1.

Your body makes its own Q10, until it slows down

Coenzyme Q10 is produced by your own cells. That production peaks at around age 23 and then falls steadily, dropping by roughly half by the age of 80. This is exactly why Q10 supplements and Q10 creams become more popular as people get older: the body simply makes less of it over time.

Q10 is not actually an antioxidant, yet

Here is the part almost no label mentions. Coenzyme Q10, in the form found in most capsules and creams (ubiquinone), cannot neutralise a single free radical on its own. It is inactive. To do its job it first has to be converted into its active form, ubiquinol. Ubiquinol is the real antioxidant: it sits in your cell membranes and stops oxidative chain reactions. When it meets oxygen it changes back into Q10, ready to be activated again. It is a continuous cycle, and that cycle only works if one gene is doing its job.

NQO1 is the gene that switches Q10 on

That gene is NQO1. The enzyme it produces performs the two-electron reduction that turns ubiquinone into ubiquinol. The detail matters: doing it in a single two-electron step avoids the harmful intermediate molecules (semiquinones) that a sloppier one-electron reduction would create. So NQO1 is not only the switch that makes your Q10 useful, it is also a protective, redox-buffering enzyme in its own right.

The one-in-eleven problem

About 9 percent of people carry a reduced-function version of NQO1, the variant rs1800566 (Pro187Ser). The change makes the enzyme unstable, so the body breaks it down faster and is left with far less working NQO1. For these people the conversion of Q10 into active ubiquinol is impaired. The practical consequence is blunt: Q10 supplements and Q10 skincare deliver little benefit, because the Q10 never gets switched on. People can spend years buying premium Q10 products that, for their genetics, were never going to work.

Why taking ubiquinol directly is not the easy fix

The obvious idea is to skip the conversion and take ubiquinol, the active form, directly. In practice this rarely solves it. Ubiquinol is extremely unstable: on contact with oxygen it reverts to inactive Q10, which makes reliable dosing in a real product very difficult.

What actually works for reduced NQO1

If your NQO1 is reduced, the better strategy is to support your antioxidant defence through routes that do not depend on it. Vitamins C and E, selenium, and alpha-lipoic acid all neutralise free radicals through independent pathways, and vitamins C and E even help regenerate Q10. Prioritising antioxidant-rich foods matters too. And if your NQO1 works normally, Q10 supplementation becomes a sensible option from around age 40, as your own production declines.

The science, in depth

NQO1 is a cytosolic, FAD-dependent oxidoreductase that uses NADH or NADPH to reduce quinones to hydroquinones. The Pro187Ser substitution disrupts the protein’s native conformation and promotes its rapid degradation, so heterozygotes show intermediate activity and reduced-function homozygotes show near-complete deficiency. Because skin is continuously challenged by UV light, pollution and inflammation, the same enzyme is part of the skin’s photoprotective (Nrf2) response, which is why reduced NQO1 also shows up in oxidative skin ageing. The most rational intervention is therefore a network rather than a single ingredient: Q10 as the pathway-aligned core, supported by vitamins C and E, alpha-lipoic acid, and the cofactors zinc and manganese.