Written by Dr Phoebe Howells. Reviewed by Dr Katherine Joseph. 

Phoebe, a doctor since 2012, has a decade of experience in Obstetrics and Gynaecology, with a focus on fertility. Her dedication led to a clinical fellowship in Reproductive Medicine at a top London fertility clinic. She's authored articles, shared insights at global conferences, and contributed to fertility trials for women with adenomyosis. Phoebe's all about crafting tailored, evidence-based care and achieving the best results for people navigating fertility challenges. While working in London, she enjoys the countryside life in Kent.

What it is, what it does, and how it supports fertility

What is CoQ10, and what does it do?

If you are confused by the different forms of CoQ10 and how they relate to fertility, you are not alone. Ubiquinone, ubiquinol, and CoQ10 may sound interchangeable, but they behave differently in the body and differ in how effectively they are used. This guide explains what CoQ10 is, how it works, and why it matters for fertility, in a clear, evidence-based way.

Meet CoQ10

Coenzyme Q10 (CoQ10) is a naturally occurring antioxidant found in every cell of the body. It plays a central role in cellular energy production and helps protect cells from oxidative damage. It is especially important in high-energy tissues such as the heart, brain and reproductive system, including the eggs. Within cells, CoQ10 works in the mitochondria, often described as the cell's powerhouses. Here, it helps convert nutrients into usable energy in the form of ATP, which fuels almost every biological process in the body. As we age, natural CoQ10 levels decline. This can affect cellular energy production, including within reproductive cells, which rely heavily on mitochondrial efficiency.

How does CoQ10 support fertility?

CoQ10 is widely regarded as one of the most important nutrients for egg quality due to its role in mitochondrial energy production. Egg cells contain a very high number of mitochondria and depend on ATP to support maturation, fertilisation and early embryo development. CoQ10 may support fertility by improving mitochondrial energy production in eggs, reducing oxidative stress within reproductive tissues and supporting overall egg quality, particularly as age increases. This becomes especially relevant from the mid-thirties onwards, when both mitochondrial function and egg quality naturally begin to decline.

What the evidence says

Research into CoQ10 and fertility is expanding and increasingly supportive of its role in reproductive health. Studies suggest that CoQ10 supplementation may be associated with improved ovarian response in IVF cycles, better embryo quality, increased fertilisation rates and higher clinical pregnancy rates in some groups of women. Controlled studies in IVF populations have shown that women taking CoQ10 for one to two months prior to treatment often experience improved egg and embryo quality, along with reduced cycle cancellation rates compared to placebo groups. A 2020 systematic review of multiple trials also found that CoQ10 supplementation was associated with improved clinical pregnancy rates and reduced IVF cycle cancellation rates in women with reduced ovarian response. While these findings are encouraging, large-scale studies focused specifically on live birth outcomes are still limited.

What type of CoQ10 should I take?

Most fertility supplements include CoQ10, but the key difference lies in the form and dose used. The most common form is ubiquinone. This is not highly soluble and must first be converted in the body to ubiquinol, the active form used at the cellular level. The efficiency of this conversion varies between individuals, meaning the amount of active CoQ10 available to the body can be significantly lower than expected. Because of this, some people choose to take ubiquinol directly, which bypasses this conversion step. However, ubiquinol is typically more expensive and less stable in supplement formulations.

 At OVUM, we use a patented form of CoQ10, called MicroActive™ CoQ10, designed for enhanced absorption and sustained release. This formulation has been shown in research to offer improved bioavailability compared to standard CoQ10 forms (3.7 times more), supporting more consistent cellular uptake. It is designed to deliver CoQ10 in a way that aligns with the body's use, supporting mitochondrial function and energy production over time, without the extremely high cost. 

Why quality matters when it comes to CoQ10

One of CoQ10’s most important roles in fertility is supporting the energy required for chromosome division during egg maturation. This process is highly energy dependent. Eggs must accurately divide and separate genetic material to ensure the correct number of chromosomes. If energy production is insufficient, chromosomal errors can occur. These become more common with increasing age and are a known contributor to infertility, failed IVF cycles and early pregnancy loss. Research suggests that reduced mitochondrial function and lower ATP production may be key mechanisms behind age-related declines in egg quality. CoQ10 supports this process by helping maintain ATP production at levels required for healthy egg development.

How CoQ10 supports chromosomal accuracy

Chromosomal errors become more common after the mid-thirties and are one of the main reasons embryos fail to implant or pregnancies do not progress. These errors are closely linked to the availability of energy within the egg. Improving mitochondrial function may help reduce the likelihood of chromosomal abnormalities during egg division. CoQ10 is naturally present in ovarian follicles, where it supports this energy-intensive process. Higher follicular CoQ10 levels have been associated with improved egg quality and higher pregnancy rates.

How much should I take and when?

The IVF clinics we work with typically recommend additional CoQ10 beyond OVUM Time to Conceive® For Women only when there is a confirmed diagnosis of diminished ovarian reserve or premature ovarian insufficiency. For most people seeking to optimise egg health, the daily dose of MicroActive™ CoQ10 200mg is considered sufficient to support mitochondrial function and egg quality. 

Because egg development takes approximately 90 days, CoQ10 is usually recommended to begin at least three months before trying to conceive or starting IVF treatment. It can generally be taken alongside other supplements, although anyone taking prescription medication should check with their healthcare provider first. There is no established maximum daily intake for most healthy individuals, but dosing should always be personalised to individual circumstances, and higher dosing should always be considered in consultation with a healthcare professional.

CoQ10 and nausea

In rare cases, CoQ10 may cause mild nausea, particularly when starting at higher doses or using more bioavailable forms. This is usually temporary and can often be improved by adjusting how it is taken. A gradual approach is often best. Starting with one capsule daily with food for the first week, increasing to two capsules in the second week and then progressing to the full dose in the third week if well tolerated. Taking CoQ10 with food, particularly earlier in the day, can also improve absorption and reduce digestive sensitivity.

Key takeaways

• CoQ10 supports mitochondrial energy production, which is essential for egg quality and early embryo development. 

• Evidence suggests potential benefits for IVF outcomes, although large-scale live birth data are still emerging. 

• The form used, absorption and timing of supplementation all play an important role in effectiveness.