Understanding the Difference Between Ubiquinol and Ubiquinone: Key Insights for Fertility and Health

When sourcing Coenzyme Q10 (CoQ10) for fertility, mitochondrial function and overall health, it is essential to understand the differences between ubiquinol and ubiquinone. Both are forms of CoQ10, but they differ in chemical structure, absorption rates, antioxidant properties and their ability to support fertility. This distinction is especially important for those trying to optimise their reproductive health.

"15 years ago, when I became interested in ubiquinol there was limited evidence on how CoQ10 could support fertility. But thanks to ongoing research, we now have a clearer understanding, which has led to more informed decisions in supplement sourcing." — Zita West

Here is a breakdown of the key differences between the two forms:

1. Chemical structure and active form

Ubiquinol is the reduced (active) form of CoQ10. It is electron-rich and ready to act as a powerful antioxidant in the body, protecting cells from oxidative damage immediately upon absorption.

Ubiquinone is the oxidised form of CoQ10. It needs to be converted into ubiquinol by the body before it can become effective in its antioxidant and energy-boosting roles. This conversion step can make ubiquinone less efficient for some people, particularly as we age.

2. Absorption and bioavailability

Ubiquinol is commonly described as a highly bioavailable form of CoQ10, and some research suggests it may be absorbed more efficiently than ubiquinone in certain formulations. Kaneka Ubiquinol, used in Zita West Kaneka Ubiquinol CoQ10, has been studied for its absorption profile, which is one reason it is often considered relevant for individuals over 35, as the body's ability to convert ubiquinone into ubiquinol can decline with age.

Ubiquinone requires conversion into ubiquinol before it can be fully utilised. As we age or in certain health conditions, this conversion becomes progressively less efficient, meaning a smaller proportion of each dose reaches the cells where it is needed.

3. Antioxidant properties

Ubiquinol acts as a potent antioxidant, neutralising harmful free radicals that can damage cells including eggs and sperm. Oxidative stress is one of the key drivers of declining egg quality and sperm motility, making antioxidant protection particularly important for anyone trying to conceive.

Ubiquinone also has antioxidant properties but must first be converted into ubiquinol to provide maximum protection. In younger individuals with efficient conversion, the practical difference may be smaller. In those over 35, the gap widens considerably.

4. Energy production and mitochondrial support

Both forms of CoQ10 play an essential role in energy production within the mitochondria. Ubiquinol is the active form that directly contributes to ATP production, the energy currency needed for cellular function. Eggs in particular are among the most energy-intensive cells in the body and depend on strong mitochondrial function for the cell divisions that determine embryo quality.

Ubiquinone must first be converted to ubiquinol to contribute to energy production, making it less efficient for those with reduced conversion ability, particularly older adults.

5. Fertility and supplementation

Ubiquinol is often considered by individuals looking to support fertility, energy levels and cellular health. For both male and female fertility, Kaneka Ubiquinol may help support mitochondrial function and antioxidant protection relevant to egg and sperm health. It is discussed both for those trying to conceive naturally and for those preparing for IVF or other assisted reproductive technologies, though it should be seen as supportive nutrition rather than a guaranteed fertility treatment.

Ubiquinone still offers benefits, but its conversion to the active form can be less efficient in individuals over 35 or those with compromised conversion ability, which is why ubiquinol is often preferred in fertility-focused supplementation, particularly where age-related conversion, absorption or mitochondrial support are considerations.

Kaneka Ubiquinol vs standard CoQ10: what is the difference?

Standard CoQ10, or ubiquinone

Standard CoQ10 supplements often use ubiquinone, the oxidised form of CoQ10. The body converts ubiquinone into ubiquinol before it acts as an antioxidant. Ubiquinone is common in many general CoQ10 supplements and may still be useful depending on dose, formulation, absorption and individual needs.

Ubiquinol

Ubiquinol is the reduced, active antioxidant form of CoQ10. It does not need the same conversion step before acting as an antioxidant, which is why it is often chosen in fertility contexts where absorption, age-related conversion and mitochondrial support are considerations.

Kaneka Ubiquinol

Kaneka Ubiquinol is a branded form of ubiquinol. Zita West uses Kaneka Ubiquinol in its fertility-focused CoQ10 supplement for women and men preparing for conception, including those focused on egg quality, sperm health and IVF preparation. It should be used according to product directions or healthcare professional advice.

For the research behind this ingredient choice, see our guide to Kaneka Ubiquinol and fertility research.

Why Zita West chooses Kaneka Ubiquinol

"For a long time now I have encouraged women and men to use Kaneka Ubiquinol in their supplements because it is the best-absorbed form of CoQ10." — Zita West

Kaneka Ubiquinol has been researched for its bioavailability and is commonly used in fertility-focused CoQ10 supplements. By using Kaneka Ubiquinol, Zita West aims to support:

• Egg quality. Read more about CoQ10 and egg health here.
• Sperm health. Read more about CoQ10 and sperm health here.
• Mitochondrial function and cellular energy production
• Reducing oxidative damage in reproductive cells

Zita West Kaneka Ubiquinol CoQ10

Uses the Kaneka form of ubiquinol, one of the more bioavailable and extensively researched CoQ10 ingredients available. Manufactured in Japan and used in clinical fertility research worldwide. Available in 60 and 120 capsule sizes.

Shop Zita West Kaneka Ubiquinol CoQ10

Why ubiquinol matters for male and female fertility

Both male and female fertility may benefit from ubiquinol's antioxidant and mitochondrial support. For women, it may help protect eggs from oxidative stress and support the energy production involved in fertilisation and early embryo development. For men, ubiquinol is studied for its possible role in supporting sperm motility and concentration, as part of a wider approach to fertility.

Because the body's ability to convert ubiquinone into ubiquinol can decline with age, supplementing directly with the active form is often considered particularly relevant for women over 35, alongside personalised guidance from a healthcare professional. Read our guide to CoQ10 and fertility after 40 here.

Related CoQ10 fertility guides

Use these Zita West guides to explore the wider CoQ10 fertility topic, including egg quality, sperm health, dosage, timing, Kaneka Ubiquinol research and pregnancy safety.

• CoQ10 and fertility guide
• CoQ10 dosage for fertility
• When to start CoQ10 before conception or IVF
• Kaneka Ubiquinol and fertility research
• CoQ10 and male fertility
• Is CoQ10 safe in pregnancy or only during conception?
• Zita West Kaneka Ubiquinol CoQ10

FAQs: ubiquinol vs ubiquinone

Is ubiquinol the same as CoQ10?

Yes. Ubiquinol is one of the two main forms of CoQ10. The other is ubiquinone. Both are the same molecule in different states — ubiquinol is the active, reduced form, and ubiquinone is the oxidised form that the body must convert before use.

Which is better for fertility, ubiquinol or ubiquinone?

Ubiquinol is often preferred in fertility supplementation, particularly for people over 35 or those preparing for IVF, because it is already in the active form and is commonly chosen where absorption and age-related conversion are considerations. The best option still depends on the product, dose and individual circumstances. Zita West uses Zita West Kaneka Ubiquinol CoQ10 in its fertility-focused formula for this reason.

How does Kaneka Ubiquinol compare to standard CoQ10?

Standard CoQ10 supplements often use ubiquinone, the oxidised form of CoQ10, which the body converts into ubiquinol. Kaneka Ubiquinol is a branded form of ubiquinol, the reduced and active antioxidant form. Zita West uses Kaneka Ubiquinol because fertility-focused supplementation often prioritises bioavailability, mitochondrial energy support and antioxidant protection relevant to egg and sperm health.

Why does age matter when choosing between ubiquinol and ubiquinone?

The body's ability to convert ubiquinone into ubiquinol declines with age, particularly from the mid-thirties onward. This means that for older individuals, a larger proportion of a ubiquinone supplement may be lost in the conversion process, reducing the effective dose that reaches reproductive cells.

What is Kaneka Ubiquinol?

Kaneka Ubiquinol is a specific, patented form of ubiquinol manufactured in Japan by Kaneka Corporation. It is one of the more bioavailable forms of CoQ10 available and has been used in multiple clinical fertility studies. It is the form used in Zita West Kaneka Ubiquinol CoQ10.

How much ubiquinol should I take for fertility?

Dosage recommendations vary depending on age, sex and whether you are preparing for natural conception or IVF. For a full breakdown, read our CoQ10 dosage guide here.

How long should I take ubiquinol before trying to conceive?

Most research recommends at least 3 months of consistent supplementation, with 6 months associated with the best outcomes for both egg and sperm quality. The 120 capsule size gives you a full 3 months at 200mg per day. For full timing guidance, read our timing guide here.

Can men take ubiquinol for fertility?

Yes. Sperm cells are highly vulnerable to oxidative stress and rely on mitochondrial energy for motility. Ubiquinol is studied for its possible role in supporting both of these areas. Male partners should follow the same 3 to 6 month supplementation timeline. Zita West Vitamen includes CoQ10 as part of a broader male fertility nutrient profile.

This content is for educational purposes only and is not intended to diagnose, treat, or replace medical advice. Always consult your GP, fertility clinic or healthcare professional before starting a new supplement, especially if you are pregnant, breastfeeding, taking medication or undergoing fertility treatment.