Ubiquinol in Fertility and Reproduction - A Conditionally Essential Nutrient for Critical Early-Life Stages

Sep 30, 2026

Infertility is a multifactorial condition with unclear causes, despite substantial evidence linking oxidative stress to both male and female infertility. Ubiquinol, the reduced form of Coenzyme Q10, participates in mitochondrial bioenergetics and can be synthesized endogenously or supplied via diet. This position paper reviews mechanisms connecting Ubiquinol with fertility and reproduction, arguing it may be conditionally essential during life stages with rising physiological demands, particularly in advanced parental age.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages19

Reading Time48 min

AccessFree to download

Abstract

Background/Objectives

Methods

Results

Conclusions

1. Introduction

2. Essential or Conditionally Essential?

Review Ubiquinol in Fertility and Reproduction: A Conditionally Essential Nutrient for Critical Early-Life Stages Emma J. Derbyshire 1, *, Sergej M. Ostojic 2 and Ahmed T. Alahmar 3 Academic Editor: Bruce W. Hollis Received: 24 November 2025 Revised: 18 December 2025 Accepted: 27 December 2025 Published: 2 January 2026 Copyright: © 2026 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. 1 Nutritional Insight, Epsom KT17 2AA, UK 2 Department of Nutrition and Public Health, University of Agder, Universitetsveien 25, 4604 Kristiansand, Norway; [sergej.ostojic@uia.no](sergej.ostojic@uia.no) 3 Department of Medical Physiology, College of Medicine, University of Babylon, Hilla 51001, Iraq; [ahmed.t.alahmar@gmail.com](ahmed.t.alahmar@gmail.com) * Correspondence: [emma@nutritional-insight.co.uk](emma@nutritional-insight.co.uk) Abstract Background/Objectives: Infertility is a multifactorial condition with an etiopathology that remains largely unclear. Although substantial evidence implicates oxidative stress (OS) as a key contributor to both male and female infertility, targeted strategies for OSmediated reproductive dysfunction are still not well defined and require further investigation. Ubiquinol is the reduced form of Coenzyme Q10 involved in mitochondrial bioenergetics. It can be synthesized by humans endogenously or provided by dietary sources—typically egg yolks, oily fish, organ meats, and in smaller amounts in nuts and seeds and leafy green vegetables. The present article reviews possible mechanisms through which Ubiquinol plays a role in the regulation of fertility and reproduction, discussing why it could be positioned as a conditionally essential nutrient. Several questions and areas for further inquiry are also proposed. Methods: The present position paper narratively summarizes evidence related to Ubiquinol fertility and reproduction, focusing on the literature from PubMed, Science Direct, and Semantic Scholar. Results: Research advancements suggest that when physiological demands rise during certain life stages, e.g., the reproductive years, the amount of Ubiquinol produced internally may not be enough to meet heightened needs, particularly with advanced maternal/paternal age. This places a heavier reliance on obtaining Ubiquinol from the diet, thus presenting itself as a conditionally essential nutrient during certain life stages. Conclusions: Overall, Ubiquinol appears to enhance mitochondrial energy production and antioxidant defense in gametes, a process that appears to aid sperm function, oocyte quality, and early embryo development. Collectively, these data indicate a key physiological role for Ubiquinol in male and female fertility, especially given its age-related decline. Keywords: advancing age; coenzyme Q10; conception; embryo development; fertility; infertility; oocyte quality; sperm function; ubiquinol 1. Introduction Reproduction is a physiologically costly process that uses considerable amounts of energy [1] . Ubiquinol, the reduced form of Coenzyme Q10 (CoQ10), forms a key part of the Ubiquinone–Ubiquinol cycle within mitochondria and is central to how cells, including reproductive cells, make energy [2] . It is the only lipid soluble antioxidant synthesized by human cells and the predominant form (>99%) of CoQ10 in the human body [3] . Female mature oocytes house around 100,000 mitochondria compared with around 1000–2500 mitochondria in other human cells [4,5] . Similarly, sperm mitochondria produce energy for the movement of the sperm, with a mature sex cell containing approximately 50–75 mitochondria in its midpiece [6,7] . Many stages of gametogenesis (sperm and oocyte maturation) are also sensitive to OS [8], and Ubiquinol as an antioxidant may help to attenuate this [9] . In normal, healthy conditions, the body typically produces

FAQs

What is the central role of Ubiquinol in fertility and reproduction?

Ubiquinol is proposed to support mitochondrial energy production and antioxidant defense in gametes, which may help sperm function, oocyte quality, and early embryo development.

Why might Ubiquinol be considered conditionally essential?

During certain life stages—especially when physiological demands rise and with age-related decline—internal production may not meet increased needs, making dietary intake more important.

What mechanisms link oxidative stress and reproductive dysfunction?

Oxidative stress can affect stages of gametogenesis, including sperm and oocyte maturation. Because Ubiquinol is an antioxidant, it may help attenuate oxidative stress–mediated reproductive dysfunction.

Sep 30, 2026

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