Coenzyme Q10 and Male Infertility: A Systematic Review

Impact of coenzyme Q10 as an adjuvant therapy to letrozole on spermiogram results and sex hormone levels in Iraqi men with infertility; randomized open label comparative study

Background: Worldwide, infertility affects about 15% of reproductive-age couples. In many cases, infertility can't be treated, however new treatment options with promising value have been involved in recent clinical trials. The aim of this clinical trial was to evaluate the impacts of adding coenzyme Q10 (CoQ10) to letrozole on the results of spermiogram and sex hormone tests in men diagnosed with idiopathic oligoasthenoteratozoospermia (iOAT) syndrome, which is a type of male defective spermatogenesis of unknown etiology. Methods: This randomized, open-label, parallel two-arm interventional study included 67 adult male patients aged 18-60 years with a confirmed diagnosis of iOAT syndrome recruited from The High Institute for Infertility Diagnosis & Assisted Reproduction Technologies/Nahrain University. Patients were randomly separated into two groups, Group A included 29 patients treated with letrozole 2.5 mg tablet orally twice a week, Group B included 38 patients treated with a combination of letrozole 2.5 mg tablet orally twice a week plus CoQ10 400 mg per day. Both groups completed treatment for three months. Semen samples, serum follicle-stimulating hormone (FSH), estradiol (E 2), and testosterone (T) were analyzed at day one, and at the end of month one, two and three. Results: Both groups showed that sperm concentration, normal morphology, total sperm count and motility, serum testosterone and FSH levels, and T/E 2 ratio were significantly increased, while estradiol levels significantly decreased after three months of treatment. Seminal fluid volume changed significantly in group A only. In comparing between the two groups, all measured parameters, apart from sperm motility and FSH level, demonstrated a significant difference after three months of treatment, while sperm volume reached significant value after only two months of therapy. Conclusions: CoQ10 as adjuvant treatment to letrozole effectively improved most of the tested sperm parameters in Iraqi men with iOAT. Registration: ClinicalTrials.gov ( NCT05847257, May 6, 2023).

Comparison of Protective Effect of Tri-circulator and Coenzyme Q10 on Myocardial Injury and the Mechanism Study by Zebrafish Model

Tri-Circulator (TC) is a product comprising coenzyme Q10 (CoQ10), Salvia miltiorrhiza, and Panax notoginseng. Individually, each of these constituents has demonstrated protective effects on myocardial injury. The purpose of this study is to evaluate the protective efficacy of TC on heart function and compare the differential effects between CoQ10 and TC. Two myocardial injury models of zebrafish, the hypoxia-reoxygenation model (H/R) and the isoproterenol (ISO, a β-receptor agonist) model, were used in this experiment. The zebrafish subjects were divided into 4 groups: control, H/R, TC, and CoQ10. Heart rate, stroke volume (SV), cardiac output (CO), ejection fraction (EF), fractional area change (FAC), and pericardial height were monitored to assess changes in heart function. The gene expression of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was studied as markers of injury/stress. TC significantly suppresses elevated heart rate induced by H/R and prevents the decrease of heart rate induced by ISO. It alleviates the pericardial infusion induced by ISO, whereas CoQ10 does not possess a similar effect. Both TC and CoQ10 significantly inhibit the decline in SV, CO, EF, and FAC induced by H/R and ISO, and suppress the expression of ANP and BNP in cardiomyocytes induced by ISO. It is noteworthy that TC demonstrates a more pronounced effect on EF, FAC, ANP, and BNP gene expression compared to CoQ10. Both TC and CoQ10 have a protective effect on myocardial injury of zebrafish. However, TC exhibits a greater efficacy compared to CoQ10 alone in mitigating myocardial injury.

The protective impact of curcumin, vitamin D and E along with manganese oxide and Iron (III) oxide nanoparticles in rats with scrotal hyperthermia: Role of apoptotic genes, miRNA and circRNA

BACKGROUND

Infertility is one of the major factors affecting most people around the world. Short-term exposure to high temperatures can cause hyperthermia, which is one of the causes of male infertility. The aim of this study was to investigate the protective effect of curcumin, vitamins D and E along with Iron (III) oxide nanoparticles (Fe2O3-NPs) and manganese oxide nanoparticles (MnO2-NPs) on semen parameters and its effect on miRNA21 and circRNA0001518 expression.

MATERIAL AND METHODS

In this study, the lower part of the rat was exposed to 43 °C for 5 weeks every other day for 5 weeks. Then the animals were killed. Tissue samples were collected for sperm parameters analysis, and tissue samples were taken for evaluation of apoptosis levels in germ cells, and RNA extraction in order to examine the expression of Bax, Bcl-2, miRNA, and CircRNA genes.

RESULTS

The results of this study showed that administration of curcumin, vitamin D, and vitamin E with Fe2O3-NPs and MnO2-NPs can improve the parameters of semen, Bax gene expression, Bcl-2 as well as miRNA and CircRNA in rats with testicular hyperthermia. In addition, curcumin by reducing the toxicity of Fe2O3 nanoparticles was able to reduce its negative effects and also reduce apoptosis in germ cells. This decrease in apoptosis was attributed to decreased Bcl-2 gene expression and increased expression of Bax, miRNA-21, and circRNA0001518.

CONCLUSION

All the results of this study confirmed that Fe2O3-NPs and Mno2-NPs containing antioxidants or vitamins are useful in improving fertility in rats due to scrotal hyperthermia. Although Fe2O3-NPs and Mno2-NPs containing both antioxidants and vitamins had a greater effect on improving fertility and reducing the toxic effects of nanoparticles.

The Effect of Selenium Therapy on Semen Parameters, Antioxidant Capacity, and Sperm DNA Fragmentation in Men with Idiopathic Oligoasthenoteratospermia

Idiopathic male infertility (IMI) remains challenging as the etiology of semen abnormalities is still unidentified. Sperm DNA fragmentation (SDF) has been suggested as a potential mechanism. Oral antioxidants including selenium have been tried for IMI with variable results. This study was undertaken to explore the effect of selenium therapy on semen parameters, antioxidant capacity, and SDF in infertile patients with idiopathic oligoasthenoteratospermia (OAT). Sixty-five infertile men with idiopathic OAT and fifty fertile controls were included in this prospective clinical study. Patients received selenium (200 μg/day) orally for 6 months. Seminal fluid parameters (WHO 5th criteria), total antioxidant capacity (TAC), catalase (CAT), and seminal SDF levels were assessed for all participants at the start of the study and after 6 months. Sperm concentration (P < 0.001), progressive motility (P < 0.001), and total motility (P < 0.01) significantly increased in patients after selenium therapy. Seminal TAC and CAT increased in patients post-therapy as compared to baseline values (P < 0.01). SDF levels significantly decreased (P < 0.001) in patients following selenium treatment in comparison to baseline values. SDF levels also correlated negatively with sperm progressive motility (r =  - 0.44, P = 0.003) and total motility (r =  - 0.48, P = 0.001). In conclusion, selenium therapy (200 μg/day) for 6 months increases sperm concentration, motility, seminal antioxidant capacity, and reduces SDF in patients with idiopathic OAT. Thus, selenium could be a promising therapy for men with IMI and may boost their fertility and fertility treatment outcomes.

Potential role of geranylgeraniol in managing statin-associated muscle symptoms: a COVID-19 related perspective

Myopathy is the most common side effect of statins, but it has not been addressed effectively. In anticipation of its wider use as a small molecule to complement the current COVID-19 management, a pharmacological solution to statin-associated muscle symptoms (SAMS) is warranted. Statins act by suppressing the mevalonate pathway, which in turn affects the downstream synthesis of isoprenoids required for normal physiological functions. CoQ10 and geranylgeraniol (GG) syntheses are reduced by statin use. However, CoQ10 supplementation has not been shown to reverse SAMS. GG is an obligatory substrate for CoQ10 synthesis, an endogenous nutrient critical for skeletal muscle protein synthesis. Multiple studies showed GG supplementation is effective in reversing SAMS. This opinion paper proposes employing GG to prevent SAMS in pleiotropic statin use, including usage in the post-COVID-19 pandemic era.

High sperm DNA fragmentation: do we have robust evidence to support antioxidants and testicular sperm extraction to improve fertility outcomes? a narrative review

To date, infertility affects 10% to 15% of couples worldwide. A male factor is estimated to account for up to 50% of cases. Oral supplementation with antioxidants could be helpful to improve sperm quality by reducing oxidative damage. At the same time, there is a growing interest in the literature on the use of testicular sperm in patients with high DNA fragmentation index (DFI). This narrative review aims to evaluate the effectiveness of supplementation of oral antioxidants in infertile men with high DFI compared to testicular sperm retrieval. The current evidence is non-conclusive because of serious risk of bias due to small sample sizes and statistical methods. Further large well-designed randomised placebo-controlled trials are still required to clarify the exact role of these to different therapeutic approaches.

Oxidative Stress and Male Infertility: The Protective Role of Antioxidants

Oxidative stress is a significant factor in male infertility, compromising sperm function and overall reproductive health. As male infertility garners increasing attention, effective therapeutic interventions become paramount. This review investigates the therapeutic role of antioxidants in addressing male infertility. A detailed examination was conducted on antioxidants such as vitamin C, E, B12, D, coenzyme Q10, zinc, folic acid, selenium, l-carnitine, l-arginine, inositols, and alpha-lipoic acid. This analysis examines the methodologies, outcomes, and constraints of current clinical studies. Antioxidants show notable potential in counteracting the negative effects of oxidative stress on sperm. Based on the evidence, these antioxidants, individually or synergistically, can enhance sperm health and reproductive outcomes. However, certain limitations in the studies call for careful interpretation. Antioxidants are integral in tackling male infertility attributed to oxidative stress. The current findings underscore their therapeutic value, yet there's a pressing need for deeper, comprehensive research. Future studies should focus on refining dosage guidelines, identifying potential side effects, and discerning the most efficacious antioxidant combinations for male infertility solutions.

The interplay of oxidative stress and immune dysfunction in Hashimoto's thyroiditis and polycystic ovary syndrome: a comprehensive review

In recent years, there has been a significant increase in the concomitant incidence of Hashimoto's thyroiditis (HT) and polycystic ovary syndrome (PCOS), both in terms of incidence, etiology, and clinical consequences. PCOS patients suffering from autoimmune thyroid diseases show insulin resistance, impaired glucose tolerance, weight gain, and metabolic and reproductive complications. Studies have shown that chronic stress and its consequence, i.e. oxidative stress, play an important role in the pathomechanism of both disorders. It has also been shown that long-term exposure to stress triggers biological mechanisms, in particular related to the regulation of the inflammatory cascade, which plays a key role in autoimmune diseases. The paper is a review of the literature on the role of chronic stress, oxidative stress, and immune processes in the pathogenesis of HT and PCOS. In addition, the review is a source of knowledge about the treatment of these diseases, and in particular the use of antioxidants in therapeutic management.

COVID-19 and Male Infertility: Is There a Role for Antioxidants?

Coronavirus disease 19 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), jeopardizes male fertility because of the vulnerability of the male reproductive system, especially the testes. This study evaluates the effects of the virus on testicular function and examines the potential role of antioxidants in mitigating the damage caused by oxidative stress (OS). A comprehensive PubMed search examined exocrine and endocrine testicular function alteration, the interplay between OS and COVID-19-induced defects, and the potential benefit of antioxidants. Although the virus is rarely directly detectable in sperm and testicular tissue, semen quality and hormonal balance are affected in patients, with some changes persisting throughout a spermatogenesis cycle. Testicular pathology in deceased patients shows defects in spermatogenesis, vascular changes, and inflammation. Acute primary hypogonadism is observed mainly in severely infected cases. Elevated OS and sperm DNA fragmentation markers suggest redox imbalance as a possible mechanism behind the fertility changes. COVID-19 vaccines appear to be safe for male fertility, but the efficacy of antioxidants to improve sperm quality after infection remains unproven due to limited research. Given the limited and inconclusive evidence, careful evaluation of men recovering from COVID-19 seeking fertility improvement is strongly recommended.

Effectiveness of Nutritional Therapies in Male Factor Infertility Treatment: A Systematic Review and Network Meta-analysis

BACKGROUND

Nutritional therapies are effective alternative treatments for male infertility or subfertility. These are cost-effective and easily implementable, unlike other advanced invasive treatments. Even moderate improvements in sperm quality could improve spontaneous pregnancy.

OBJECTIVE

We aimed to compare the effectiveness of all nutritional therapies in male infertility/subfertility treatment and ranked their efficacy based on type and etiology. We intend to aid clinicians with an evidence-based approach to affordable and safer initial infertility treatment for those who mainly do not wish to have other advanced invasive treatments or could not afford or have access to them.

METHODS

We included 69 studies with 94 individual study arms identified from bibliographic databases and registries. We included studies in adult men with proven infertility or subfertility that investigated nutritional or dietary supplement therapies compared with control or placebo and at least reported on a sperm parameter. We undertook a network meta-analysis and performed a pairwise meta-analysis on all sperm parameter outcomes and meta-regression. No language or date restriction was imposed. A systematic article search was concluded on August 29, 2022.

RESULTS

Our network meta-analysis is the first to compare all dietary interventions in a single analysis, sub-grouped by intervention type and type of infertility. L-Carnitine with micronutrients, antioxidants, and several traditional herbal supplements showed statistically and clinically significant improvement in sperm quality. Meta-regression identified that improvement in the sperm count, motility and morphology translated into increased pregnancy rates (p < 0.001; p < 0.001; p < 0.002, respectively). In particular, L-carnitine with micronutrient therapy (risk ratio [RR]: 3.60, 95% CI 1.86, 6.98, p = 0.0002), followed by zinc (RR 5.39, 95% CI 1.26, 23.04, p = 0.02), significantly improved pregnancy rates. Men with oligozoospermia (RR 4.89), followed by oligoasthenozoospermia (RR 4.20) and asthenoteratozoospermia (RR 3.53), showed a significant increase in pregnancy rates.

CONCLUSION

We ranked nutritional therapies for their ability to improve sperm quality in men with infertility. Nutritional therapies, particularly L-carnitine alone or combined with micronutrients, significantly improved sperm parameters and pregnancy rates even under severe conditions. We believe these affordable solutions may be valuable for people without access to or who do not wish to undergo more invasive and costly fertility treatments.

Effect of CoQ10 Supplement on Spermogram Parameters and Sexual Function of Infertile Men Referred to The Infertility Center of Fatemieh Hospital, Hamadan, Iran, 2019: A Randomized Controlled Trial Study

BACKGROUND

The aim of this study was to investigate the effects of the antioxidant supplement of CoQ10 and placebo in the male infertility treatment.

MATERIALS AND METHODS

The randomized controlled trial study was designed as a clinical trial. Samples in each group consisted of 30 members. The first group received 1 daily dose of 100 mg coenzyme Q10 capsules and the second group received a placebo treatment. Treatment in both groups lasted 12 weeks. Before and after the intervention of semen analysis, hormonal measurement of testosterone, prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyroid stimulating hormone (TSH) were done. Sexual function was assessed before and after the intervention by using the International Index of Erectile Dysfunction questionnare.

RESULTS

The mean age of participants was 34.07 (5.26) years in the CoQ10 group and 34.83 (6.22) in the placebo one. Normal volume of semen (P=0.10), viscosity (P=0.55), sperm count (P=0.28), and sperm motility (P=0.33) in the CoQ10 group increased without statistically significant differences. But the normal sperm morphology increased with statistically significant differences in the CoQ10 group (P=0.01). There was an increase in normal FSH levels and testosterone levels in the CoQ10 group compared with the placebo patients, but these differences were not statistically significant (respectively P=0.58, P=0.61). The results also revealed that the scores of erectile function (P=0.95), orgasm (P=0.86), satisfaction with sexual intercourse (P=0.61), overall satisfaction (P=0.69) and the score of the International Index of Erectile Function (IIEF, P=0.82) were greater after the intervention in the CoQ10 group than in the placebo group although the difference was not statistically significant.

CONCLUSION

The use of CoQ10 supplement can improve sperm morphology; however, in other sperm parameters and also in some hormones increased after the intervention, this was not statistically significant and therefore the result is not conclusive (registration number: IRCT20120215009014N322).

Coenzyme Q10 improves sperm motility and antioxidant status in infertile men with idiopathic oligoasthenospermia

OBJECTIVE

Oxidative stress is a key player in the development of idiopathic male infertility (IMI), and various antioxidants have been used for the treatment of IMI with inconsistent results. Coenzyme Q10 (CoQ10) is a cofactor and an antioxidant that may improve semen parameters and reduce oxidative stress in patients with idiopathic oligoasthenospermia (OA). Therefore, this study aimed to explore the effect of CoQ10 on semen parameters and antioxidant markers in patients with idiopathic OA.

METHODS

Fifty patients with idiopathic OA and 35 fertile controls were enrolled in this prospective controlled study. All participants underwent a comprehensive fertility assessment. All patients received CoQ10 (300 mg/day) orally once daily for 3 months. Semen parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured in patients and controls at the start of the study and after 3 months.

RESULTS

Treatment with CoQ10 resulted in increased sperm progressive motility (p<0.05), total motility (p<0.01), seminal TAC (p<0.01), SOD (p<0.05), GPx (p<0.001), and seminal CoQ10 (p<0.001) levels and reduced ROS (p<0.01) in patients as compared to baseline. Sperm concentration and motility were also significantly correlated with antioxidant measures and seminal CoQ10 levels (r=0.38-0.57).

CONCLUSION

CoQ10 therapy (300 mg/day for 3 months) improved sperm motility and seminal antioxidant markers in patients with idiopathic OA. Therefore, CoQ10 could be a promising treatment for patients with idiopathic infertility and may improve their fertility potential.

Studies on improving semen quality and increasing pregnancy chances through the in vitro addition of L-carnitine and coenzyme Q10 to semen in patients with asthenozoospermia

Background

At present, L-carnitine (LC) and coenzyme Q10 (CoQ10), as used clinically to treat male infertility caused by asthenozoospermia (ASZ) is still mainly administered orally, but some patients with ASZ still show no significant improvement in sperm motility and spouse pregnancy rate. Prodom is a device used to assist reproduction, which is temporarily fitted onto the penis to facilitate conception by helping the wife inject a certain drug into the vagina. This study used Prodom-assisted LC/CoQ10 in the treatment of patients with ASZ and evaluated the effect of this method on sperm motility and clinical pregnancy, with the goal of finding a comfortable, low-cost, effective method.

Results

During the trial period, 232 cases completed the trial, while 25 cases did not. During in vitro testing, the progressive sperm motility in the LC group, CoQ10 group, LC combined with CoQ10 group, and the semen blank control group was 24.3 ± 4.6% and 38.1 ± 5.1%, 23.0 ± 4.8% and 36.9 ± 4.4%, 28.4 ± 5.0% and 43.8 ± 5.4%, 19.7 ± 4.4% and 26.0 ± 4.9%, respectively. There were statistically significant differences in progressive sperm motility among the groups (all P values < 0.05). The pregnancy rates of the Prodom-assisted LC treatment group, Prodom-assisted CoQ10 treatment group, Prodom-assisted LC combined with CoQ10 treatment group, and oral LC combined with CoQ10 treatment group in the clinical treatment stage were 38.2, 35.4, 57.1, and 30.3%, respectively; the time to conception was 6.1 ± 1.8, 6.2 ± 1.8, 3.4 ± 0.9, and 7.9 ± 2.0, months respectively; and the treatment costs were $2350 ± 457, $2455 ± 434, $1348 ± 411, and $2684 ± 334, respectively. The differences in pregnancy rate, time to conception, and treatment costs among the groups were statistically significant (all P values < 0.05).

Conclusions

The supplementation of in vitro semen with LC/CoQ10 can improve sperm motility. LC/CoQ10 injected into the spouse’s vagina with the assistance of a Prodom can increase the pregnancy rate, shorten the time to conception, and reduce the cost of treatment in patients with ASZ.

Trial registration

ChiCTR2000040349 (registry: http://www.chictr.org.cn/).

Date of registration: November 28, 2020.

Coenzyme Q10 alleviates testicular endocrine and spermatogenic dysfunction induced by high-fat diet in male Wistar rats: Role of adipokines, oxidative stress and MAPK/ERK/JNK pathway

The current study investigated the possible protective effects of Coenzyme Q₁₀ (Co Q₁₀ ) on rat model of high-fat diet (HFD) induced testicular dysfunction. Thirty male Wistar rats were allocated randomly into three groups: control, HFD, HFD + Co Q₁₀ (75 mg/kg/day) groups. Animals were sacrificed after 3 months and epididymal sperm suspension, blood, and testes were collected for further analysis. In comparison to the untreated HFD group, the Co Q₁₀ treated group revealed significantly increased serum testosterone, adiponectin levels, and decreased LH, FSH, and leptin levels. In addition, HFD resulted in significant increase in testicular oxidative stress (increased MDA, iNOS, NO, XO & decreased catalase, SOD, GSH) and inflammation (increased pJNK/JNK, pERK/ERK, and p-p38MAPK/MAPK), while Co Q₁₀ was effective to ameliorate these changes. In addition, Co Q₁₀ significantly increased sperm count, motility and viability that were markedly deteriorated by HFD. Regarding testicular ultrastructure, seminiferous tubular diameter and epithelium height were reduced in HFD group and Co Q₁₀ significantly improved these testicular changes. Finally, a significant reduction in spermatogenic cell proliferation was detected by PCNA fluorescent expression and Co Q₁₀ significantly reversed this change. In summary, our results indicated that Co Q₁₀ could suppress testicular dysfunction produced by HFD. This protective effect could be attributed to its antioxidant, anti-inflammatory properties and to its effect on adipokines and spermatogenic cell proliferation. So, Co Q₁₀ may be a promising food supplement to protect against testicular dysfunction induced by HFD.

Metabolic Syndrome and Male Fertility: Beyond Heart Consequences of a Complex Cardiometabolic Endocrinopathy

Metabolic syndrome (MetS) is a highly prevalent condition among adult males, affecting up to 41% of men in Europe. It is characterized by the association of obesity, hypertension, and atherogenic dyslipidemia, which lead to premature morbidity and mortality due to cardiovascular disease (CVD). Male infertility is another common condition which accounts for about 50% of cases of couple infertility worldwide. Interestingly, male infertility and MetS shares several risk factors (e.g., smoking, ageing, physical inactivity, and excessive alcohol consumption), leading to reactive oxygen species (ROS) production and increased oxidative stress (OS), and resulting in endothelial dysfunction and altered semen quality. Thus, the present narrative review aims to discuss the pathophysiological mechanisms which link male infertility and MetS and to investigate the latest available evidence on the reproductive consequences of MetS.

In vitro fertilization using sperm activated by ML‐2–3 isolated from Morinda lucida Bentham leaves

Purpose

ML‐2–3 is a novel tetracyclic iridoid derived from Morinda lucida Bentham leaves. This compound has anti‐trypanosomal and anti‐leishmanial effects. In this study, the authors investigated effects of ML‐2–3 on in vitro fertilization (IVF) rates, motility, and acrosome reaction of the mouse sperm.

Methods

IVF was performed using sperm from BALB/cByJJcl mice treated with ML‐2–3. Computer‐assisted sperm analysis (CASA) was performed on the sperm of C57BL/6J mice to investigate sperm motility. The effect of ML‐2–3 on the acrosome reaction was examined by observing the fluorescence of sperm labeled with the acrosin‐EGFP transgene.

Results

ML‐2–3 improved IVF in BALB/cByJJcl mice with low fertilization rates. The optimum concentration of ML‐2–3 in sperm pre‐culture medium was 20 µM, and no significant toxicity of ML‐2–3 was observed in developing embryos at this concentration. ML‐2–3 affected sperm motility but not the acrosome reaction. ML‐2–3 increased the IVF rate of mouse sperm that had been refrigerated for 3 days.

Conclusions

ML‐2–3 can improve the outcome of IVF and motility without inducing the acrosome reaction in mice. These effects of ML‐2–3 on sperm behaviors are different from those of the similar drugs.

Redox Balance in Male Infertility: Excellence through Moderation-"Μέτρον ἄριστον"

Male infertility, a relatively common and multifactorial medical condition, affects approximately 15% of couples globally. Based on WHO estimates, a staggering 190 million people struggle with this health condition, and male factor is the sole or contributing factor in roughly 20–50% of these cases. Nowadays, urologists are confronted with a wide spectrum of conditions ranging from the typical infertile male to more complex cases of either unexplained or idiopathic male infertility, requiring a specific patient-tailored diagnostic approach and management. Strikingly enough, no identifiable cause in routine workup can be found in 30% to 50% of infertile males. The medical term male oxidative stress infertility (MOSI) was recently coined to describe infertile men with abnormal sperm parameters and oxidative stress (OS), including those previously classified as having idiopathic infertility. OS is a critical component of male infertility, entailing an imbalance between reactive oxygen species (ROS) and antioxidants. ROS abundance has been implicated in sperm abnormalities, while the exact impact on fertilization and pregnancy has long been a subject of considerable debate. In an attempt to counteract the deleterious effects of OS, urologists resorted to antioxidant supplementation. Mounting evidence indicates that indiscriminate consumption of antioxidants has led in some cases to sperm cell damage through a reductive-stress-induced state. The “antioxidant paradox”, one of the biggest andrological challenges, remains a lurking danger that needs to be carefully avoided and thoroughly investigated. For that reason, oxidation-reduction potential (ORP) emerged as a viable ancillary tool to basic semen analysis, measuring the overall balance between oxidants and antioxidants (reductants). A novel biomarker, the Male infertility Oxidative System (MiOXSYS^®), is a paradigm shift towards that goal, offering a quantification of OS via a quick, reliable, and reproducible measurement of the ORP. Moderation or “Μέτρον” according to the ancient Greeks is the key to successfully safeguarding redox balance, with MiOXSYS^® earnestly claiming its position as a guarantor of homeostasis in the intracellular redox milieu. In the present paper, we aim to offer a narrative summary of evidence relevant to redox regulation in male reproduction, analyze the impact of OS and reductive stress on sperm function, and shed light on the “antioxidant paradox” phenomenon. Finally, we examine the most up-to-date scientific literature regarding ORP and its measurement by the recently developed MiOXSYS^® assay.