The desire to do everything possible to improve IVF outcomes is entirely understandable — and the fertility supplement and wellness industry exploits it aggressively. This guide cuts through the noise and focuses on what the published clinical evidence actually supports, what is plausible but unproven, and what can be safely set aside.

The honest summary: lifestyle factors matter, but probably less than the biological factors that determine your IVF outcome (age, ovarian reserve, sperm quality). No supplement prevents chromosomally abnormal eggs. What you can meaningfully affect is optimising the physiological conditions in which treatment takes place.

Weight and BMI

This is the lifestyle factor with the strongest and most consistent evidence base.

For women: BMI significantly outside the normal range (below 18.5 or above 30) is associated with reduced IVF success rates. High BMI is linked to poorer egg quality, lower fertilisation rates, reduced implantation rates, and higher miscarriage rates. Most UK fertility clinics have BMI thresholds for treatment — commonly 30–35 as an upper limit for NHS IVF. For detail on NHS eligibility, see NHS IVF age limits and criteria by ICB.

The effect of weight loss in overweight patients before IVF is real: studies show improved hormone profiles, ovulatory function, and — in some studies — improved IVF outcomes after meaningful weight loss (typically 5–10% of body weight). The challenge is that meaningful weight loss takes time, which may conflict with age-related urgency.

For men: Male BMI is associated with sperm quality — obesity is linked to increased sperm DNA fragmentation, lower testosterone, and reduced motility. Weight loss in overweight male partners can improve semen parameters.

Diet: Mediterranean Pattern Has the Best Evidence

Of all dietary patterns studied in the fertility context, the Mediterranean diet has the most consistent supporting evidence. Characterised by:

  • High intake of vegetables, legumes, whole grains, fruit, nuts
  • Olive oil as the primary fat source
  • Moderate fish and seafood
  • Low red meat, processed foods, and sugar

Several observational studies show associations between Mediterranean diet adherence and improved IVF outcomes. A 2018 prospective study in the journal Human Reproduction found that women with high Mediterranean diet scores had significantly higher rates of clinical pregnancy and live birth in IVF. The mechanisms proposed include reduced systemic inflammation, better antioxidant status, and improved endometrial environment.

This is not a prescription for perfection — the evidence is observational, not from randomised trials. But adopting broadly Mediterranean eating patterns in the 3–6 months before IVF is a low-risk, potentially beneficial approach.

Foods to reduce: Ultra-processed foods, high-sugar drinks, trans fats, and excessive red meat. These are consistently associated with worse fertility markers in epidemiological studies.

Alcohol

The evidence on alcohol and IVF is consistent enough to warrant clear advice: minimise alcohol intake during IVF treatment, and ideally in the 3 months beforehand.

Studies show that even moderate alcohol consumption (3–7 units per week) is associated with reduced IVF success rates in women. In men, alcohol reduces testosterone and is associated with reduced sperm quality. Several prospective cohort studies show a dose-dependent reduction in IVF live birth rates with increasing alcohol intake.

The biologically cautious position — avoiding alcohol entirely during a cycle — is supported by the evidence and recommended by most UK fertility specialists.

Smoking

Smoking is one of the lifestyle factors with the clearest negative effect on fertility. It is associated with:

  • Accelerated ovarian reserve decline (equivalent to advancing age by 1–4 years in some studies)
  • Reduced fertilisation rates
  • Lower implantation rates
  • Higher miscarriage rates
  • In men: reduced sperm count, motility, and increased DNA fragmentation

Stopping smoking before IVF is strongly recommended. The benefit of stopping is not immediate — sperm production takes approximately 3 months, and egg quality effects take longer — but stopping as early as possible before a cycle is worthwhile.

Exercise

Moderate exercise is beneficial and is not associated with harm in IVF. Regular moderate aerobic exercise (walking, swimming, cycling) is associated with better weight management, reduced inflammation, and lower stress levels — all of which support IVF preparation.

What to avoid during stimulation: High-intensity exercise and contact sports are generally advised against during ovarian stimulation, when the ovaries are enlarged. There is a small risk of ovarian torsion (twisting) with very enlarged ovaries under physical stress. This does not mean all exercise should stop — walking is fine throughout. The caution is specifically around high-intensity or vigorous activity once follicles are growing.

Supplements: What Has Evidence

Folic acid (400–500 mcg daily): Recommended for anyone trying to conceive, as it reduces neural tube defect risk in early pregnancy. No direct effect on IVF success rates, but essential for embryo health in early pregnancy. Start at least one month before a cycle.

Vitamin D: Deficiency is common in the UK (particularly in winter months and in patients with limited sun exposure). Low vitamin D is associated with poorer IVF outcomes in several studies. Testing your vitamin D level and supplementing if deficient (typically 1,000–2,000 IU daily for maintenance, higher if correcting deficiency) is reasonable.

CoQ10 (ubiquinol form, 200–600 mg daily): Coenzyme Q10 is a mitochondrial antioxidant involved in energy production in cells, including eggs. There is biological plausibility for benefit, and some small studies show improved egg quality markers with CoQ10 supplementation, particularly in older patients. Evidence is limited but the supplement is low-risk. Many fertility specialists consider it worth taking for patients over 35.

Omega-3 fatty acids: Anti-inflammatory effects and supportive of cell membrane quality. Some evidence of benefit for sperm quality in men. Reasonable to take as part of general fertility preparation.

For men — antioxidants: The combination of vitamin C, vitamin E, zinc, selenium, and CoQ10 has some evidence supporting reduction in sperm DNA fragmentation and improvement in motility. Low-risk to take 3 months before a cycle.

Supplements to Be Cautious About

DHEA: Sometimes recommended for poor ovarian responders. Some evidence from small studies, but not recommended without specialist supervision — DHEA has hormonal effects and is not appropriate for all patients.

High-dose vitamin E or A: High doses of fat-soluble vitamins can be harmful. Stick to recommended daily amounts unless specifically advised by your clinic.

Herbal supplements: Many herbal preparations (including royal jelly, red clover, and various Chinese herbal compounds marketed for fertility) have limited evidence and some have hormonal effects that may interfere with treatment. Disclose any herbal supplements to your clinic before starting a cycle.

Sleep and Stress

Both sleep deprivation and chronic psychological stress are associated with hormonal disruption and inflammation that may affect fertility. Sleep quality is worth optimising in the months before IVF, and addressing high-stress life circumstances where possible.

On stress specifically: the evidence does not support a direct causal link between stress levels and IVF failure (see IVF and mental health). Managing stress matters for your wellbeing and ability to sustain treatment — not because stress "prevents implantation."

Frequently Asked Questions

Q: How long before IVF should I start changing my diet?

A: The ideal timeframe for lifestyle and dietary changes is 3 months before a cycle — this covers one sperm production cycle and allows time for egg quality factors to be influenced (though the impact on egg quality is less well established than for sperm). Even changes made in the 4–6 weeks before a cycle are worth making.

Q: Should I take a fertility-specific supplement package?

A: Branded "fertility supplements" vary enormously in formulation and are not regulated as medicines. Rather than paying premium prices for branded packages, a more evidence-based approach is: folic acid, vitamin D (especially October–March in the UK), and CoQ10 (particularly if over 35). Add omega-3 and an antioxidant blend for male partners. These can be sourced individually at lower cost than branded fertility packs.

Q: Is caffeine harmful during IVF?

A: The evidence on caffeine and IVF is inconsistent. Most UK guidelines suggest limiting caffeine to approximately 200 mg/day during fertility treatment (equivalent to 1–2 cups of coffee). Complete elimination is not supported by strong evidence, but moderation is sensible.

Q: Can losing weight improve my IVF chances if I'm overweight?

A: Yes, particularly if BMI is above 30. The improvement in hormonal profile, ovarian response, and endometrial receptivity associated with weight loss is clinically meaningful. If time permits before starting IVF, weight loss of even 5–10% of body weight in overweight patients can improve outcomes and may also affect NHS eligibility in ICBs with BMI thresholds.

Q: My clinic recommended acupuncture during IVF. Should I try it?

A: The HFEA classifies acupuncture as an add-on with limited evidence of benefit for IVF outcomes. Multiple randomised controlled trials have failed to show a statistically significant improvement in IVF live birth rates with acupuncture. Some patients find it helpful for stress management, which is a legitimate reason to try it — but it should not be framed as improving clinical outcomes.

This article is for information only and does not constitute medical advice. Discuss supplements and lifestyle changes with your fertility clinic before starting a cycle.