The Supplement Series: Can this help halt the fertility decline for men and women and even help prevent developmental complications?!

Natural aging, plus modern lifestyles/environmental onslaught has a very simple effect over time: a gradual deterioration of our cells. That’s life. However, it is particularly brutal on our eggs and fertility in particular and often much sooner than we would like….

Question is - what (if anything?!) can we do to get in the way of this?

One supplement - Coenzyme Q10 or CoQ10 - may have something to say about this.

I am usually deeply sceptical on supplements, but, here is what the research says:

On the whole, we are waiting longer to have kids. This is great for careers/women in the workplace, financial stability etc, but, it is not without consequence. Men’s sperm regenerates every 3 months or so, women however, are born with their entire egg reserve which will drop off and deteriorate in quality and quantity over time. Lucky us (!)

This is why, as we age, it gets harder to have a baby (lower number of eggs/ovarian reserve and lower quality as the eggs are exposed to ‘stress’ factors for longer).

One of the main culprits behind this is what is known as Oxidative Stress over time. Click here for much more, but in a nutshell: all cells within the body produce what is known as oxidation. It is part of normal cell life and essentially is a bi-product of generating energy within the energy-hub of a cell: the Mitochondria. The trouble comes when we produce more oxidation than we have antioxidant supply (your body’s mop) to clean it up. That's when we get Oxidative stress and problems like deterioration and cell damage. Ultimately this can cause DNA mutations and potential reproductive, pregnancy and development issues. To dig in to much more/what the causes are for this click here.

Bottom line though: its not what we want, especially over long periods of time…..

Can CoQ10 potentially protecting us from this?

First and foremost it is an antioxidant - one of the body’s most powerful defence tools (click here for more on the power of the antioxidant) and the very thing that counteracts the potentially damaging effect of oxidation. It is a fat soluble compound that is produced naturally in your body but alas declines as we age. It plays a crucial role in how our cells generate energy (and frankly they need a lot of energy to build a whole new person!)

At the root of how CoQ10 works is the fact that it gets involved in the very area where this oxidation occurs - the mitochondria within cells - which makes it potentially very effective as a protective factor:

‘The mitochondrial respiratory chain is a powerful source of reactive oxygen species, which play a major role in the deterioration of cell structures. As CoQ10 is an integral part of the respiratory chain and thereby located exactly where free radicals are generated, its antioxidant properties are very important for the overall antioxidative capacity of the mitochondria.’ (2)

When it comes to our purposes - preserving good eggs and sperm - it is particularly important as research has shown that this oxidative stress/deterioration plays a significant role in diminished ovarian reserve/egg and sperm quality:

‘The potentially adverse effects of Oxidative Stress (OS) in most stages of human fertility can be counteracted by administration of several mitochondrial nutrients known as antioxidants, which have been demonstrated to increase energy production in mitochondria and to protect cells from OS.’ (3)

Translation: the mitochondria within the cell (or in our case the eggs/early embryos) are the area of focus here - they are the most abundant organelles within eggs/early embryos and generate around 90% of reactive oxygen species (1). When there is ‘dysfunction’ and we get problems - antioxidants like CoQ10 - can be particularly effective:

‘Mitochondrial dysfunction… is strongly associated with poor reproductive performance due to high and long-time exposure to OS which causes diminishing ovarian reserves...chromosomal abnormalities...poor oocyte quality. Antioxidants may be one of the keys to preventing reproductive performance against OPS induced aging by increased mitochondrial function.’ (3)

It doesn't stop with getting pregnant either - it has also been suggested to play a role in pregnancy too:

Oxidative stress has been linked to preeclampsia and preterm labor (2) of course there can be many factors behind this but we do know that the protective levels of CoQ10 that we have in our body decline with age (1,3)

Ok, so sounds interesting but as always - theory is great - but what do the results/research trials actually suggest?

As always, there is lots of animal research here (easier to do and control) and less when it comes to humans as of course it is harder to control the many variables when it comes to people. That is sometimes why people say there is ‘not enough evidence’. The most important thing to note however, is that this does not mean that it is not effective, it just means there have not been enough human trials to say for sure. That being said, the research we do have there are some interesting results with support for its use. Take a quick look as to what some research has demonstrated:

  • Protection from decline in ovarian reserve

  • Protection against ovarian aging/premature decline

  • Improved results in IVF (blastocyst formation)

  • Ovulation induction/improved rates  

  • Fertilisation rate

  • Increase in the number of high quality embryos

  • Enhances ovarian response to stimulation (1)

‘In the clinical setting, CoQ10 supplementation led to better response to ovulation induction and lower odds of fatal aneuploidy in 35-43yr old women.’ (1) Further, Ben-Meir et al did an extensive study with results demonstrating that ‘that CoQ10 supplementation preserves ovarian reserve and increased mitochondrial performance and ovulation rates.’ (3)

So we can see, there is decent evidence to suggest that CoQ10 can help reduce the rate of decline in reserves that we do inevitably face with time, however, in addition in animals we have data to suggest that it can actually improve ovarian reserve and AMH:

‘CoQ10 has been also associated with improved ovarian reserve. In rodents, CoQ10 administration [led] to increase in the serum AMH concentrations, improved AMH-positive follicle count and reduced the number of atretic follicles.’ (1)

Now to be clear, at this point there is not a lot of information as to exactly how exactly this is achieved (the effect of oxidative stress on men’s fertility is better understood at this point) and there is less evidence around an increase in AMH levels in human trials, however what we do have is encouraging:

‘These results suggest that CoQ10 could be effective to protect ovarian reserve and prevent ovarian damage by counteracting OS related ovarian damage.’ (3)

Boys: this is for you:

Men are impacted less by the aging process than women when it comes to fertility (typical!), however oxidative stress is a known and well appreciated factor when it comes to a decline in male fertility that is rife in our modern times (click here for more). Turns out that CoQ10 can be very interesting for boys too:

‘In men, the amount of CoQ10 in the seminal fluid shows a direct correlation with semen parameters. A strong correlation between sperm count, motility and ubiquinol (reduced form of Q10) has been reported.’ (4)

Are there any negatives and how much should we be taking?

So the good news here is that research suggests that there are no real downsides to taking this and it is safe up to around 900 mg/day. The less good news is that there is no clear consensus of how much to take and how long to take it for:

‘Optimal timing, duration, dose of Q10 supplementation remain has been demonstrated that CoQ10 is well tolerated and safe for healthy adults at intake of up to 900mg/day.’ (1)

A number of the studies we considered looked at shorter duration (60 days) and then up to 6-8 months of use and ranged from 200mg - 600 mg doses/day.

So how much should you take?

Well obviously first and foremost you should always consult with your doctor before you do anything, and secondly, always follow the instructions on the supplement that you buy. Both important steps to take before you consider this as a supplement.

Which supplement is best?

Now this is where it gets more interesting. The trouble with the supplement market is that it is pretty unregulated and often not very clear (which is why we are pretty sceptical on the whole on supplements here at Better Babies). However, when it comes to CoQ10, research suggests that on the margin you want to take the reduced form which is known as Ubiquinol:


‘Reduced Q10 is the most abundant endogenous cellular antioxidant and is a safe and effective therapeutic antioxidant.’ (2)

The research is frankly a bit patchy about what form is ‘best’ but some studies have suggested that the reduced form was slightly better absorbed (5). We know that it’s no good taking these supplements unless they can be absorbed of course. It may be marginal but worth bearing in mind.

Bottom line: the research (particularly more recent) is actually relatively compelling and as long as you are not exceeding a dose of 900 mg/day. If you are consulting with your doctor and following the manufacturer's guidelines there appears no downside to taking it. So - if you’re concerned about aging and your reserves there is a decent chunk of evidence to suggest it really can help and limited research to show any negative effects so worth considering.


(1) XU Y, NUSENBLAT V, WANG S: Pretreatment with Coenzyme Q10 improves ovarian response and embryo quality in low-prognosis young women with decreased ovarian reserve: a randomised controlled trial. Reproductive Biology and Endocrinology: 2018: 16: 29

(2) GIANNUBILO S, TIANO L, MAZZANTI L: Amniotic Coenzyme Q10: Is it Related to Pregnancy outcomes? Antioxidants & Redox Signalling. 2014 Oct 10: 21(11): 1582-1586

(3) OZCAN P, FICICIOGLU C, ESREFOGLU M: Can Coenzyme Q10 supplementation protect the ovarian reserve against oxidative damage? Journal of Assisted Reproduction and Genetics. 2016 Sep: 33(9): 1223-1230\

(4) GARBE COLLINS G, ROSSI BV: The impact of lifestyle modifications, diet and vitamin supplementation on natural fertility: Fertility Research and Practise: 2015: 1: 11

(5) EVANS M, BAISLEY J, BARSS S, GUTHRIE N: A randomised, Double-Blind, Crossover Trial Comparing the Bioavailability of Two CoQ10 Formulations: Journal of Functional Foods: 2009 65-73

This article is for informational purposes only. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment and should never be relied upon for specific medical advice. The information on this website has been developed following years of personal research and from referenced and sourced medical research. Before making any changes we strongly recommend you consult a healthcare professional before you begin.