The Testosterone Blueprint
WomenSome evidenceNormal

CoQ10

A well-tolerated antioxidant worth considering for egg quality and energy, especially over 35 or on a statin.

Dose
100–200 mg/day (higher in fertility protocols) · Ubiquinol better absorbed
When to take
With a fatty meal · ~3 months for fertility
Pairs well with
Omega-3; vitamin D; myo-inositol (fertility)
Avoid
Reduces warfarin effect — check first; very high fertility doses without guidance
Side effects
Very well tolerated; rarely mild digestive upset

What CoQ10 does

CoQ10 (coenzyme Q10) powers the mitochondria — the tiny engines inside every cell, including a woman's eggs. Your natural levels fall with age, which is part of why egg quality declines from the mid-30s. As an antioxidant, CoQ10 also protects cells from damage and supports heart and energy metabolism.

Does it actually help? An honest answer

The most interesting evidence for women is around egg quality and fertility, especially over 35. Studies suggest CoQ10 may improve the mitochondrial energy supply in ageing eggs, and it is widely used in fertility protocols, though the human trials are still modest in size. Its antioxidant and heart benefits are better established. The honest summary: promising and well-tolerated for fertility support, with solid general antioxidant value — but not a guaranteed fertility fix.

Signs you might benefit

Trying to conceive later (mid-30s onward), taking a statin (which lowers your own CoQ10), or wanting general antioxidant and energy support.

Richest food sources

CoQ10 is found in small amounts across the diet, with the richest sources being organ meats (heart, liver and kidney are by far the highest), followed by fatty fish such as sardines, mackerel and herring, then beef, pork and chicken. Plant sources are more modest but include soybean and rapeseed oils, nuts (peanuts, pistachios, sesame seeds), and vegetables like spinach and broccoli. The practical catch: even the richest foods supply only a few milligrams a day, far below the 100–200 mg used for fertility and energy — so food maintains your baseline, but a supplement is needed for therapeutic amounts. Because your body's own production declines from your mid-30s (the same window egg quality starts to fall) and statins lower it further, supplementing makes most sense for women over 35, those trying to conceive, and anyone on a statin.

How much to take

A common dose is 100–200 mg per day, with some fertility protocols using more (up to 600 mg) under guidance. The ubiquinol form absorbs better than ubiquinone, especially over 40.

When and how to take it

Take it with a meal containing fat, as it is fat-soluble. For fertility, it is usually taken for at least three months — the time it takes an egg to mature.

Too much / what to watch for

Very well tolerated; occasionally mild digestive upset or trouble sleeping if taken late. Take it earlier in the day if it affects your sleep.

What to stack with

Omega-3, vitamin D, and for fertility, myo-inositol — a common combination for egg quality.

What to avoid — supplements and medicines

CoQ10 can reduce the effect of the blood thinner warfarin, so check with your doctor if you take it.

Who should be cautious

Anyone on warfarin, and those on blood-pressure medication (CoQ10 may lower blood pressure slightly).

Quality — what to look for on the label

Choose ubiquinol (the active, better-absorbed form) in an oil-based softgel, third-party tested.

Bottom line

CoQ10 is a well-tolerated antioxidant worth considering for egg quality and energy, particularly over 35 or on a statin. Take 100–200 mg of ubiquinol daily with food, and allow about three months for fertility benefits.

Sources

Studies on CoQ10 and oocyte quality in older women; NIH information on CoQ10; reviews of CoQ10 in fertility protocols.

Chapter 10 · Fertility
If you'd like to try it

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Based on guidance from the NHS, NICE, Cleveland Clinic and peer-reviewed research.

By M. Videika, author of The Testosterone Blueprint · Reviewed June 2026

General information, not a substitute for personal medical advice — always consult your doctor or a qualified health professional before making health decisions. If you are pregnant, breastfeeding, trying to conceive, under 18, or taking medication, speak to your doctor before starting any supplement.