Supplements when trying to conceive: What dose ranges have been used in research?

When preparing for pregnancy - particularly before IVF - one of the most common questions about individual supplements is:

“How much should I take?”

Published research explores a range of doses, and clinical practice may sometimes differ - particularly in IVF settings, where certain nutrients are used at higher levels.

Coenzyme Q10 is one example. While many published studies use doses between 100–600mg daily, some fertility clinics use higher amounts e.g. 400mg twice daily, in specific circumstances, particularly for women in their late 30s/40s or those with reduced ovarian reserve.

The tables below summarise ranges used in research. They are provided for educational purposes only and are not personalised medical advice.

Individual needs vary depending on diet, medical history, laboratory values and clinic protocols. Always discuss supplements with your GP or fertility specialist before starting or adjusting anything.

Commonly studied supplement ranges for women

Nutrient / Supplement	Dose range	Notes
Coenzyme Q10 (CoQ10)	100–600mg/day (some clinics use up to 400mg twice daily)	Central to mitochondrial energy production (ATP synthesis). Oocytes are highly energy-dependent cells, and CoQ10 has been studied in relation to cellular energy metabolism and age-related mitochondrial function.
Folate / Folic Acid	400–800µg/day	Essential for DNA synthesis, cell division and methylation processes. Folate contributes to maternal tissue growth during pregnancy and normal blood formation. Adequate maternal folate status reduces risk of neural tube defects in the developing foetus.
L-arginine	2–6g/day	Precursor to nitric oxide, involved in vascular tone and blood flow. Studied in fertility contexts in relation to endometrial environment and circulation.
Magnesium	200-400mg daily	Involved in over 300 enzymatic reactions, including energy production, DNA synthesis, and hormone signalling. Contributes to normal energy-yielding metabolism and reduction of tiredness and fatigue. Magnesium glycinate is a highly absorbable form that is often gentler on the digestive system compared with other forms.
Myo-inositol	2–4g/day	Involved in insulin signalling and ovarian follicle signalling pathways. Studied particularly in women with PCOS and in relation to oocyte development.
Omega-3 (DHA/EPA)	500–2000mg/day	Structural components of cell membranes. DHA contributes to maintenance of normal brain function and vision. Maternal DHA intake contributes to normal brain and eye development of the foetus and breastfed infant. Also studied in relation to inflammatory balance and reproductive tissue function.
Pycnogenol	50–150mg/day	Plant extract rich in procyanidins with antioxidant properties. Studied in relation to oxidative stress and vascular function within reproductive tissues.
Vitamin C	500–1000mg/day	Antioxidant that contributes to protection of cells from oxidative stress and supports normal collagen formation. Oxidative balance is an area of interest in reproductive research.
Vitamin D	400–2000IU/day (10–50µg/day)	Acts as a hormone precursor and plays a role in gene expression and cell division. Vitamin D contributes to normal immune function and normal cell division. Vitamin D receptors are present in reproductive tissues.
Vitamin E	100–400IU/day (~67–268mg/day)	Fat-soluble antioxidant that contributes to protection of cells from oxidative stress. Studied in relation to cellular membrane stability and oxidative balance.

 

Commonly studied supplement ranges for men

Coenzyme Q10 (CoQ10)	100–400mg/day	Involved in mitochondrial ATP production. Sperm cells are highly energy-dependent, and CoQ10 has been studied in relation to sperm motility and cellular energy metabolism.
Folate / Folic Acid	400–800µg/day	Required for DNA synthesis, repair and methylation. Folate contributes to normal amino acid synthesis and homocysteine metabolism, processes relevant to sperm DNA integrity.
L-carnitine	1–3g/day	Transports fatty acids into mitochondria for energy production. Concentrated in the epididymis and studied in relation to sperm motility and maturation.
Magnesium	200–400mg/day	Supports energy metabolism and muscle function. Magnesium-dependent enzymes are involved in DNA replication and cellular signalling.
Omega-3 (DHA/EPA)	500–2000mg/day	DHA is incorporated into sperm cell membranes and influences membrane fluidity.
Vitamin C	500–1000mg/day	Antioxidant contributing to protection of cells from oxidative stress. Oxidative balance is a key area of interest in sperm health research.
Vitamin D	400–2000IU/day	Contributes to normal immune function and cell division. Vitamin D receptors are present in male reproductive tissue.
Vitamin E	100–400IU/day	Fat-soluble antioxidant contributing to protection of cells from oxidative stress and cellular membrane stability.

 

References

Coenzyme Q10 – Women (200–600 mg/day commonly studied)

Bentov Y, Hannam T, Jurisicova A, Esfandiari N, Casper RF.
Coenzyme Q10 supplementation and oocyte aneuploidy in women undergoing IVF-ICSI treatment.
Clinical Medicine Insights: Reproductive Health. 2014;8:31–36.

Xu Y, Nisenblat V, Lu C, et al.
Pretreatment with coenzyme Q10 improves ovarian response and embryo quality in low-prognosis young women with decreased ovarian reserve: a randomized controlled trial.
Reproductive Biology and Endocrinology. 2018;16:29.

Coenzyme Q10 – Men (100–400 mg/day commonly studied)

Safarinejad MR.
Efficacy of coenzyme Q10 on semen parameters, sperm function and reproductive hormones in infertile men.
Journal of Urology. 2009;182(1):237–248.

Lafuente R, González-Comadran M, Solà I, et al.
Coenzyme Q10 and male infertility: a meta-analysis.
Journal of Assisted Reproduction and Genetics. 2013;30(9):1147–1156.

Bakri S, Saleh R, Cayan S, Birowo P, Atmoko W, Zainal ATF, Giffari M.
Efficacy and Safety of Coenzyme Q10 in Idiopathic Male Infertility: A Systematic Review and Meta‑Analysis of Randomized Trials.
World Journal of Men’s Health. 2025;[online ahead of print].

Salvio G, Cutini M, Ciarloni A, Giovannini L, Perrone M, Balercia G.
Coenzyme Q10 and Male Infertility: A Systematic Review.
Antioxidants (Basel). 2021;10(6):874.

Myo-inositol (2–4 g/day commonly studied)

Unfer V, Carlomagno G, Dante G, Facchinetti F.
Effects of myo-inositol in women with PCOS: a systematic review.
Gynecological Endocrinology. 2012;28(7):509–515.

Papaleo E, Unfer V, Baillargeon JP, et al.
Myo-inositol in patients with PCOS: a novel method for ovulation induction.
Gynecological Endocrinology. 2007;23(12):700–703.

Omega-3 (500 mg–2 g/day commonly studied in reproductive contexts)

Salas-Huetos A, Rosique-Esteban N, Becerra-Tomás N, et al.
Effect of omega-3 fatty acids on semen quality: a systematic review and meta-analysis.
Andrology. 2018;6(5):686–696.

Chiu YH, Chavarro JE, Gaskins AJ, et al.
Fatty acid intake and outcomes of assisted reproduction in women.
Human Reproduction. 2018;33(8):1561–1570.

L-Carnitine – Men (1–3 g/day commonly studied)

Lenzi A, Sgrò P, Salacone P, et al.
A placebo-controlled double-blind randomized trial of the use of combined L-carnitine and L-acetyl-carnitine treatment in men with asthenozoospermia.
Fertility and Sterility. 2004;81(6):1578–1584.

Antioxidants (Vitamin C, E ranges reflected in male fertility trials)

Showell MG, Mackenzie-Proctor R, Brown J, Yazdani A, Stankiewicz MT, Hart RJ.
Antioxidants for male subfertility.
Cochrane Database of Systematic Reviews. 2014 (updated 2022).

Vitamin D (400–2000 IU commonly studied in reproductive populations)

Lerchbaum E, Obermayer-Pietsch B.
Vitamin D and fertility: a systematic review.
European Journal of Endocrinology. 2012;166(5):765–778.

Magnesium (general intake context 200–400 mg/day)

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA).
Scientific Opinion on Dietary Reference Values for magnesium.
EFSA Journal. 2015;13(7):4186.