Evidence-Based Fertility Supplements: Nutrients for Egg Quality to support fertility
Written by fertility nutrition expert, Dr. Conor Kerley
Dr. Conor Kerley is a multi-award winning nutrition researcher, leading clinician as well as a member of the European Fertility Society and European Society of Human Reproduction and Embryology (ESHRE).
I have collected, read and analyzed every single human study regarding nutrition, nutrients, supplements and fertility outcomes, including egg quality.
Common questions I’m asked in clinic and online include
how to improve egg quality
and
supplements for egg quality
Read on for the answer…
Egg quality naturally declines with age but emerging research suggests that certain nutrients and fertility supplements may help support egg health, mitochondrial function, and reproductive outcomes.
Egg quality is a key factor in female fertility. It refers to how healthy and genetically normal a woman’s eggs (oocytes) are, which affects the chances of fertilization, healthy embryo development, and the likelihood of a successful pregnancy.
However, egg quality naturally declines with age and can also be affected by
· lifestyle,
· metabolic health,
· oxidative stress,
· hormonal balance
Emerging research suggests that certain nutrients and fertility supplements may help support egg health, mitochondrial function, and reproductive outcomes.
Egg quality is extremely important for both natural fertility and assisted reproduction (IVF, IUI, ICSI). You may have heard of the term, ‘it all starts with the egg’
What is Egg Quality?
High-quality eggs usually:
- Have the correct number of chromosomes
- Can be fertilized successfully
- Can develop into a healthy embryo
Poor-quality eggs may:
- Fail to fertilize
- Stop developing early
- Lead to miscarriage due to chromosomal abnormalities.
Chromosomal issues like those seen in Down syndrome are more likely when egg quality declines.
Why egg quality matters for fertility?
Oocyte (egg) quality strongly influences fertility outcomes. It affects:
· whether the egg can get fertilized
· development of healthy embryos
· implantation of those embryos
· occurrence of a successful pregnancy
Even if fertilization happens, poor egg quality often prevents the embryo from developing normally. Here are the key reasons:
1. Chromosomal health
2. Embryo development
3. Fertilization success
4. Implantation and pregnancy success
In simple terms, egg quality determines whether the embryo gets the correct genetic material and the cellular tools needed to grow into a healthy baby.
What Causes Poor Egg Quality?
Age
Egg quality declines naturally with age.
Approximate trend:
- 20s–early 30s: highest egg quality and fertility
- Mid–late 30s: noticeable decline
- 40+: significant decline and higher miscarriage risk
This decline is strongly linked to increased chromosomal errors.
Lifestyle
- Smoking
- Excess alcohol
- Poor diet
- Lack of sleep
- High stress
Medical Conditions
Some conditions can affect egg quality and ovulation, such as:
- Polycystic Ovary Syndrome (PCOS)
- Endometriosis
Environmental Factors
- Exposure to toxins or pollutants
- Certain medications or chemotherapy
Signs of Reduced Egg Quality
You usually cannot feel or directly see egg quality, but doctors may estimate fertility with tests such as:
- AMH (Anti-Müllerian Hormone) blood test
- Antral follicle count ultrasound
- FSH hormone test
These measure ovarian reserve, not egg quality exactly, but they help estimate fertility potential.
How to Improve Egg Quality Naturally
While age-related decline cannot be reversed, some habits may help support reproductive health.
Lifestyle Habits That Improve Egg Quality
· Healthy body weight
· Regular exercise
· Avoid smoking
· Good sleep – especially in complete darkness
· Stress management
· Reduce endocrine disruptors
· Balanced diet (Mediterranean-style diet)
· Some specific nutrients and supplements
The nutrients which have been shown in human research studies in women to impact egg health are listed below
Fertility supplements for improving egg quality:
Emerging human research suggests that specific nutrients can influence
· Oxidative stress,
· Low-grade chronic inflammation,
· Mitochondrial dysfunction.
Since these 3 factors strongly influence egg quality, specific nutrients in specific doses offer support for women to improve egg quality.
Based on available human research, several nutrients have been studied for their role in supporting egg health.
These nutrients target key biological mechanisms that influence egg quality, including:
· Oxidative stress
· Inflammation
· Mitochondrial function
· Hormonal balance
The most studied nutrients for egg quality include:
Antioxidants and Mitochondrial Support
1. CoQ10
2. Alpha lipoic acid
3. Vitamin E
4. Selenium
Metabolic & Hormonal Support
5. Myo-inositol
6. Omega-3
7. Vitamin D
8. Resveratrol*
Methylation & Homocysteine Control
9. B6
10. B9 (5-MTHF)
11. B12
Thyroid & Reproductive Function
12. Iodine
Circadian / Hormonal Signalling
13. Melatonin
Therefore these 13 nutrients are the ultimate supplements for egg quality
*Resveratrol and fertility
There are several human trials regarding female fertility and resveratrol. One of these trials reported that resveratrol could improve egg quality in women while another 3 studies reported benefits. Although some resveratrol studies reported benefits, another resveratrol study reported harm. Therefore, I, Dr Conor Kerley, don’t normally recommend resveratrol. A 2019 study reported that resveratrol supplementation was ‘strongly associated with a 46% decrease in clinical pregnancy rate and a 160% increased risk of miscarriage’.
I also advise caution with supplements containing resveratrol.
Many fertility supplements contain small amounts of the 13 key nutrients or leave out them out entirely.
In addition, research shows that specific doses and forms of nutrients matter.
Research-backed doses matter. But combining these individual nutrients correctly can be complicated, requiring multiple supplements and careful dosing.
Fertility Phix was developed to simplify this process and includes the above nutrients in research-backed doses and bioavailable forms.
Fertility Phix is an all in one fertility supplement and was formulated to provide:
· nutrients to support egg quality
· nutrients to support mitochondrial function for cellular energy
· antioxidants to help reduce oxidative stress
· nutrients that support hormonal balance
·
If you are have or think you may have suboptimal egg quality and are trying to conceive, targeted nutritional support may be a valuable part of your strategy. Explore Fertility Phix here or contact us to discuss whether it is right for you.
Designed for the 90-Day Egg Development Window
Eggs take 90–120 days to mature, meaning nutritional support should ideally begin at least 3 months before conception.
Who is Fertility Phix suitable for?
Anybody on a fertility journey who wants to provide themselves with a comprehensive mix of research backed nutrients to support egg quality and overall fertility.
When to start Fertility Phix?
Lifestyle changes, including supplements are recommended for at least 3 months before conception. This is because a woman’s eggs take approximately 3 to 4 months (roughly 90-120 days) to mature -this is why we offer a 3 month bundle where if you add 3 boxes Fertility Phix sachets to your cart, you save a massive 60 euro and get free shipping anywhere in the world!
Final Thoughts from Dr. Kerley
Egg quality plays a crucial role in fertility, influencing fertilization, embryo development, and pregnancy outcomes.
While age remains the strongest factor affecting egg quality, lifestyle habits, diet, and targeted nutritional support may help optimise the biological processes that support egg health.
Because eggs take approximately 90–120 days to mature, changes in nutrition and supplementation should ideally begin at least three months before trying to conceive.
For individuals looking for comprehensive nutritional support during their fertility journey, Fertility Phix provides a research-informed combination of nutrients designed to support egg quality, mitochondrial function, and reproductive health.
Key Takeaways
• Egg quality is a major factor in fertility. Healthy eggs are more likely to fertilize successfully, develop into high-quality embryos, and result in a healthy pregnancy.
• Egg quality naturally declines with age, especially after age 35, largely due to increased chromosomal abnormalities and reduced mitochondrial function.
• Oxidative stress, inflammation, and mitochondrial dysfunction are key biological factors that can negatively affect egg health.
• Certain nutrients have been studied in human fertility research for their potential to support egg quality, ovarian function, and embryo development.
• Key nutrients linked to egg health include:
· Coenzyme Q10
· Alpha lipoic acid
· Myo-inositol
· Vitamin D
· Omega-3 fatty acids
· B vitamins (B6, B9 as methylfolate, B12)
· Vitamin E
· Selenium
· Iodine
• Homocysteine balance is important for egg health. Adequate intake of vitamins B6, B9 (5-MTHF), and B12 helps regulate homocysteine levels.
• Lifestyle factors matter. Diet quality, sleep, stress management, avoiding smoking, and reducing alcohol intake can all influence reproductive health.
• Nutritional changes should ideally begin at least 3 months before trying to conceive, because eggs take approximately 90–120 days to mature.
Frequently asked questions
Can egg quality be improved?
Egg quality naturally declines with age and cannot be completely reversed. However, research suggests that lifestyle factors and certain nutrients may support biological processes involved in egg health, including mitochondrial function, oxidative balance, and hormone regulation.
What supplements are commonly used to support egg quality?
Some of the most commonly studied nutrients for egg health include:
· Coenzyme Q10
· Alpha lipoic acid
· Myo-inositol
· Vitamin D
· Omega-3 fatty acids
· B vitamins (especially B6, B9 as methylfolate, and B12)
· Vitamin E
· Selenium
· Iodine
These nutrients may support antioxidant defence, mitochondrial energy production, and metabolic health.
How long does it take to improve egg quality?
Eggs take approximately 3–4 months (90–120 days) to mature before ovulation. Because of this, lifestyle changes and nutritional strategies are usually recommended at least three months before trying to conceive.
Does egg quality decline after age 35?
Yes. Fertility gradually declines with age, and egg quality begins to decline more rapidly after age 35. This is largely due to increased chromosomal abnormalities and reduced mitochondrial function in the eggs.
Can diet affect egg quality?
Diet appears to play an important role in reproductive health. Research suggests that dietary patterns such as the Mediterranean diet, which emphasises vegetables, fruits, fish, olive oil, and whole foods, may support fertility and overall metabolic health.
What is AMH and does it measure egg quality?
AMH (Anti-Müllerian Hormone) is a hormone measured in blood tests that helps estimate ovarian reserve, or the number of remaining eggs. However, AMH does not directly measure egg quality.
When should I consider fertility supplements?
Some people consider nutritional support when:
· Trying to conceive
· Preparing for IVF or other assisted reproductive treatments
· Age-related fertility concerns
· Conditions such as PCOS or reduced ovarian reserve
It is always advisable to discuss supplements with a GP or fertility specialist before starting them.
Fertility Is NOT a female only issue
Note, regardless of egg quality, fertility issues are NOT female only.
Approximately 40–50% of infertility cases involve male factors.
For this reason, both partners should be assessed and follow a fertility-supportive lifestyle.
If you are a woman trying to conceive, make sure your male partner has been tested, is following a fertility friendly lifestyle and check our these blogs:
Nutrients for Male Fertility, Sperm Quality and sperm count - The Science
Nutrients for Male Fertility, Sperm Quality and sperm motility - The Science
Nutrients for Male Fertility, Sperm Quality and sperm morphology - The Science
Nutrients for Male Fertility, Sperm Quality and sperm DNA fragmentation - The Science
Nutrients for Male Fertility, Sperm Quality and varicocele - The Science
In addition to egg quality , other common conditions contributing to fertility issues in women, include:
Advanced age
Antiphospholipid syndrome
Endometriosis
Fibroids
Hypothalamic amenorrhea
Lupus
Premature ovarian insufficiency (POI)
Thyroid issues, especially Hashimoto's or autoimmune thyroiditis
Please note: This article is for educational purposes only and does not replace personalised medical advice.
· Not all supplements are appropriate for everyone. Always consult your GP or fertility specialist before starting supplements, particularly if undergoing assisted reproductive treatment.
· Timing matters – lifestyle changes, including supplements are recommended for at least 3 months before conception. This is because a woman’s eggs take approximately 3 to 4 months (roughly 90-120 days) to mature before ovulation, in a process known as folliculogenesis.
· Dosing matters – scientific research has reported benefits of certain doses. It is important to seek out and consume these doses to get the same benefits.
