Supplements for trying to conceive (TTC)

The TTC supplement stack — rationale by ingredient and partner

For the female partner: prenatal multivitamin (or equivalent) with methylfolate 800 µg + iodine 150 µg + choline (often gap-fill needed)

Start at least 3 months before conception attempts. Methylfolate 800 µg/day (5-MTHF — the bioactive form, particularly important for the ~30% of people with reduced MTHFR enzyme activity) is the most-evidenced pre-conception supplement: reduces neural tube defect risk by ~70%. Iodine 150 µg/day for fetal neurodevelopment. Choline 450 mg/day during TTC and pregnancy — most prenatal vitamins are inadequate in choline, so a separate 250–300 mg choline bitartrate may be needed.

For the female partner: vitamin D3 to 25-OH-D target 30–50 ng/mL

Vitamin D deficiency is associated with reduced fertility, longer time-to-conception, and worse IVF outcomes. Test and target rather than supplementing blindly. Most pregnancies will need 2,000–4,000 IU/day depending on baseline status, BMI, and sun exposure.

For the female partner: omega-3 DHA 200 mg/day minimum (often higher for EPA co-benefits)

DHA is essential for fetal brain development; deficiency in the mother during preconception and pregnancy is associated with reduced offspring neurocognitive outcomes. A 200 mg DHA minimum is standard prenatal guidance; many TTC and pregnant women benefit from higher combined EPA+DHA (1 g/day) for maternal cardiovascular and mood benefits.

For the female partner: CoQ10 ubiquinol 200–600 mg/day, particularly age 35+

Oocyte mitochondrial function declines with age and is a major driver of age-related fertility decline. CoQ10 supports mitochondrial function in oocytes during the 90-day maturation window. Small RCT signal in IVF cycles, particularly diminished ovarian reserve cohorts. Reasonable adjunct, especially for women 35+ or with prior diminished response to stimulation.

For the female partner with PCOS or ovulatory dysfunction: myo-inositol 2 g + folic acid 200 µg twice daily

Multiple RCTs in PCOS show improved ovulatory frequency and pregnancy rates with myo-inositol. Generally well-tolerated; pregnancy-safe. Combinations with D-chiro-inositol (40:1 myo:DCI ratio) may be optimal.

For the male partner: antioxidant + mitochondrial sperm-quality stack

Spermatogenesis takes 74 days; supplement at least 3 months before conception attempts. The MOXI trial and subsequent meta-analyses (Cochrane male-fertility supplements review) show modest improvements in pregnancy rates with combined antioxidant supplementation, with CoQ10, zinc, selenium, vitamin C, vitamin E, and L-carnitine as the most-evidenced components. CoQ10 ubiquinol 200–400 mg/day, zinc 15–22 mg with 1–2 mg copper, omega-3 1–2 g/day, methylfolate 400 µg/day, vitamin D to target. Brand "male fertility" combinations (FertilAid, Proxeed, etc.) compile this stack; individual ingredients work too.

For both partners: identify and address underlying conditions before assuming the supplement layer is rate-limiting

Thyroid function (TSH ideally <2.5 for TTC), iron status (low ferritin contributes to anovulation), vitamin D as above, B12 (particularly in vegan/vegetarian diet), and (for the male partner) varicocele on examination, prior medication exposures (testosterone in any form is acutely fertility-destroying), recent illness with fever, prolonged heat exposure of testes. Couples should have basic fertility evaluation if not conceiving after 12 months of regular timed intercourse (6 months if female partner is 35+, or sooner with known risk factors).