Nutrients2026n = 21 comparison-level records from 18 reports
Meta AnalysisHuman
This systematic review and meta-analysis set out to see whether vitamin D supplements raise testosterone or related markers in men. It pooled randomized trials measuring total testosterone, SHBG (sex hormone-binding…
Nutrients2026n = 34
RCTHuman
This study looked at how high-intensity exercise and vitamin D3 supplements affect vitamin D levels differently in trained athletes versus untrained men. It compared 22 mixed martial arts athletes and…
Cureus2026n = 4,389 eligible out of 4,601 screened
Cross SectionalHuman
This study set out to see if taking oral medications or zinc supplements affects zinc levels in the blood and whether that links to better sperm health or fertility outcomes…
Journal of health, population, and nutrition2026
Narrative ReviewHuman
This review looked at how nutrition shapes male fertility at the cellular level, focusing on how nutrients affect sperm production, function, and DNA. It pulled together human, animal, and lab…
Frontiers in nutrition2026n = 39 trials
Meta AnalysisHuman
This study set out to see if creatine supplements work differently when taken with resistance training versus other types of exercise. It pooled data from 39 trials in healthy men…
Journal of the International Society of Sports Nutrition2026n = 28
RCTHuman
This study compared two forms of omega-3 supplements, structured triglycerides (STGs) and physical mixtures (PMs), to see which better boosts blood EPA levels and muscle performance. Twenty-eight healthy young men…
Arab journal of urology2026n = 200 initially, 174 completed follow-up
RCTHuman
This study tested whether CoQ10, L-carnitine (an amino-acid-like nutrient the body uses to turn fat into energy), or both together improve semen quality in men with low sperm count, poor…
Scientific reports2026
Meta AnalysisHuman
This study set out to examine whether astaxanthin (a potent antioxidant) could improve sperm quality after freezing and thawing. It pooled data from multiple studies to see how astaxanthin affected…
Nutrients2026n = 75 enrolled, 70 completed
RCTHuman
This study looked at whether vitamin D changes how well metformin (a common diabetes drug that lowers blood sugar) can bring down prolactin (a pituitary hormone that suppresses testosterone when…
Cureus2026n = Phase I: 10; Phase II: 52.
RCTHuman
This study set out to compare a micronized form of creatine monohydrate (KleanCREATINE™) with a standard creatine supplement in active men. It had two parts: first, a small test in…
Advanced science (Weinheim, Baden-Wurttemberg, Germany)2026n = 39 out of 43 enrolled completed the study
RCTHuman
This study tested whether a combination of nicotinamide (a form of vitamin B3) and pyridoxine (vitamin B6) could boost muscle stem cell activity and speed up muscle repair after intense…
Aging clinical and experimental research2026n = 30
RCTHuman
This study set out to see if combining creatine (a compound stored in muscle that helps regenerate quick energy) and β-hydroxy-β-methylbutyrate (HMB, a muscle-preserving supplement) with exercise could improve mobility…
The British journal of nutrition2026n = 46
RCTHuman
This study set out to see if omega-3 (n-3 PUFA) supplements could boost muscle growth and strength gains from weight training in healthy young men already eating plenty of protein.…
Nutrients2026n = 11
RCTHuman
This study set out to see whether the timing of a single dose of creatine (a well-studied supplement that helps with short, intense efforts) affects strength performance during a workout.…
Scientific reports2026n = 156
Cross SectionalHuman
This study aimed to assess how much adult men know about male fertility, focusing on medical and lifestyle factors that affect it. Researchers surveyed 156 men of reproductive age using…
Nutrients2026n = 56
RCTHuman
This study looked at whether ashwagandha (an herbal supplement traditionally used to blunt stress) helps team-sport athletes handle the strain of pre-season training, when the stress hormone cortisol and fatigue…
Current issues in molecular biology2025
Narrative ReviewHuman
This review set out to examine how heavy metals like lead, mercury, and cadmium affect sperm quality and male fertility, focusing on their role in oxidative stress and antioxidant imbalance.…
Journal of dietary supplements2025
Narrative ReviewHuman
This review set out to explore how dietary fatty acids (FAs) affect sperm quality and male fertility. It looked at recent studies on how different FAs influence sperm production and…
Antioxidants (Basel, Switzerland)2025
Narrative ReviewHuman
This review looked at how oxidative stress (cell damage from unstable molecules called reactive oxygen species, a normal byproduct of metabolism that turns harmful when it outpaces the body's defenses)…
Food science & nutrition2025n = 8,686
Cross SectionalHuman
This study looked at whether eating more omega-3 fatty acids (healthy fats found in fish and some plants) is linked to higher testosterone levels in men. It used data from…
Nutrients2025n = 14
RCTHuman
This study looked at whether a short, high-dose creatine (a compound stored in muscle that helps regenerate quick energy for short, hard efforts) routine improves sleep, performance, thinking, and recovery…
Metabolites2025
Narrative ReviewHuman
This narrative review set out to explore how oxidative stress (an imbalance between harmful reactive oxygen species and the body's defenses) affects fertility in men and women, and whether dietary…
Nutrients2025n = 50 studies included
Meta AnalysisHuman
This systematic review and meta-analysis set out to see whether dietary supplements improve male fertility. It pooled 50 randomised trials in which men took a supplement for at least 12…
Current opinion in urology2025
Narrative ReviewHuman
This review gathers recent evidence on what damages male fertility and how much of it can be undone. Smoking raises sperm DNA fragmentation (breaks in the genetic material inside sperm)…
Nutrients2025n = 38 (20 placebo, 18 ashwagandha)
RCTHuman
This study set out to see whether ashwagandha, a herb widely sold for stress and performance, adds anything to interval training. Interval training here meant repeated hard efforts on a…
Frontiers in pharmacology2024n = 877 (462 CoQ10-treated, 415 untreated/placebo-treated)
Meta AnalysisHuman
This systematic review and meta-analysis set out to assess whether coenzyme Q10 (CoQ10) supplementation improves semen quality and male hormone levels. It pooled data from eight randomized controlled trials involving…
Reproductive biology and endocrinology : RB&E2018
Narrative ReviewHuman
This review pulled together what is known about how everyday life affects a man's fertility, covering age, psychological stress, nutrition, physical activity, caffeine, scrotal temperature, hot water and mobile phone…