Coenzyme Q10 (often called CoQ10) is one of those molecules many people have heard of, but few could describe clearly. And yet, its impact on fertility—both eggs and sperm—has been a major topic of research in the past decade. Let’s dive into what CoQ10 is, how it works, and why it matters so much for anyone hoping to grow their family.
CoQ10 is a fat-soluble antioxidant found in virtually every cell of the human body. Its main job? Helping cells make energy. Our cells transform the food we eat into fuel (ATP), and CoQ10 is right at the heart of this process. Mitochondria—the “batteries” inside our cells—use CoQ10 to keep things running smoothly.
But CoQ10 is also a powerful antioxidant, which means it helps protect cells from damage, especially that caused by oxidative stress. And that brings us to fertility.
Eggs and sperm might seem tiny, but both need enormous amounts of energy to mature, develop, and—hopefully—create an embryo. The quality of eggs (oocytes) and sperm directly impacts the chances of conception, whether naturally or with help from assisted reproductive techniques.
But as we age, both eggs and sperm experience a natural decline in mitochondrial function—and research shows levels of CoQ10 in our bodies gradually decrease with age, too (NIH).
Egg quality is one of the most important factors in female fertility, particularly in people over 35. Studies suggest that declining egg quality is often linked to decreased mitochondrial energy and increased oxidative stress inside the egg cell.
Research in both animal and human studies is promising. For example, a published study in the journal Fertility and Sterility found that women with diminished ovarian reserve who took CoQ10 supplements before IVF cycles had more mature eggs and better embryo quality than those who did not (Fertility and Sterility, 2018).
In animal studies, older mice who received CoQ10 supplementation produced more eggs, and those eggs were healthier and led to higher pregnancy rates (Nature Medicine, 2010).
It’s no secret: egg quality tends to decline as we age, especially after 35. One key reason is mitochondrial dysfunction. As egg cells age, their mitochondria often falter—which means lower energy and more free radical damage. Since CoQ10 supports both antioxidant defenses and energy production, ensuring optimal levels may help buffer this natural decline.
Egg quality often gets discussed more, but sperm health is just as important when it comes to conception. Sperm need plenty of energy to swim, and their DNA must be protected from oxidative stress. Here, too, CoQ10 plays a role.
One 2019 review in the journal Urology concluded that CoQ10 supplementation (usually 100–300 mg per day in studies) led to measurable improvements in sperm motility and morphology, particularly in men with unexplained infertility (Urology, 2019).
CoQ10 can be found in various foods, though the amounts are relatively small:
While diet contributes to overall levels, research on fertility typically focuses on supplements, as therapeutic doses (100–600 mg/day) are higher than what diet alone can provide.
Most human studies use doses between 100–400 mg/day, often starting three months before trying to conceive or in preparation for IVF. Effects can take 8–12 weeks to become noticeable, as eggs and sperm require several weeks to mature.
CoQ10 has a solid safety profile in clinical trials, with only mild potential side effects such as digestive upset or insomnia, which are rare. However, anyone taking medications or with underlying health conditions should check with a healthcare professional before starting new supplements.
Importantly, CoQ10 is not a “magic cure.” It will not override severe sperm or egg dysfunction, genetic problems, or offer a guarantee. Instead, think of it as part of a broader toolkit—a gentle but powerful support for the natural processes already working within your body.
While evidence on CoQ10 is promising, remember that optimal fertility draws on many aspects of well-being:
CoQ10 is one thoughtful addition to the broader picture of nourishing eggs and sperm from the inside out. For many people—especially those over 35, or those preparing for fertility treatments—it offers evidence-based, gentle support for the mitochondria at the center of every cell’s energy and resilience.
Fertility is a journey with ups, downs, and many unknowns. When you’re seeking next steps, it’s empowering to have access to options—rooted in science, and grounded in kindness—to help you move forward with greater hope and care for yourself, wherever you are on your path.