Endpoint
Sperm concentration
Mature male germ cells derived from spermatids. As spermatids move toward the lumen of the seminiferous tubules, they undergo extensive structural changes including the loss of cytoplasm, condensation of chromatin into the sperm head, formation of the acrosome cap, the sperm midpiece and the sperm tail that provides motility.
CAT:outcome/sperm-concentrationreported in 10^6/mL3 findings from 3 compounds
What moved it
How to read these marks3 findings · 3 compounds · 3 null · by evidence strength
| Compound | Direction | Findings | Strongest evidence |
|---|---|---|---|
| Lepidium meyenii | no effect | 1 | Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers. |
| Zn(2+) | no effect | 1 | Evidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers. |
| α-tocopherol | no effect | 1 | Evidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence. |
Every finding here is a null result.
Measured, no effect detected
3 findings
Lepidium meyenii — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull result“An increase during the treatment was noted at total sperm count and sperm concentration in both the maca and the placebo group, while the placebo group showed better performance, even though not statistically different.”
Quoted verbatim from Evaluation of the effect of Lepidium meyenii Walpers in infertile patients: A randomized, double-blind, placebo-controlled trial.. - Study
- RCT
- Dose
- 2.8 g/day (seven 400 mg capsules per day)
- Population
- infertile men aged 28-52 years with impaired semen quality
Evaluation of the effect of Lepidium meyenii Walpers in infertile patients: A randomized, double-blind, placebo-controlled trial.2021PMID:34585449Industry fundedPermalink
Zn(2+) — no detected effect on
ModerateEvidence strength: moderate. Human evidence with one recorded weakness, or capped at moderate by its design or by unread numbers.FindingNull result“However, there were no significant effects of zinc supplementation on the sperm viability, sperm concentration, sperm count or percentage of abnormal sperm morphology (and).”
Quoted verbatim from Zinc levels in seminal plasma and their correlation with male infertility: A systematic review and meta-analysis.. - Study
- meta-analysis
- Population
- Infertile men in the pooled studies of zinc supplementation on sperm parameters
Zinc levels in seminal plasma and their correlation with male infertility: A systematic review and meta-analysis.2016PMID:26932683Permalink
α-tocopherol — no detected effect on
Very limitedEvidence strength: very limited. Human evidence with major recorded weaknesses, or non-human, uncontrolled or unverified evidence.FindingNull result“Pooled analysis of two randomized trials showed no significant additional benefit of vitamin E versus control for sperm concentration (SMD 0.09, 95% CI-0.59 to 0.76; p = 0.80) or sperm motility (SMD 0.15, 95% CI-0.19 to 0.49; p = 0.39).”
Quoted verbatim from Effect of adjuvant vitamin E supplementation on sperm parameters after varicocelectomy: a systematic review and meta-analysis.. - Study
- meta-analysis
- Population
- Men after varicocelectomy; pooled analysis of two randomised trials of adjuvant vitamin E versus control
Effect 0.09 standardised mean difference, 95% CI -0.59 to 0.76
Effect of adjuvant vitamin E supplementation on sperm parameters after varicocelectomy: a systematic review and meta-analysis.2026PMID:42165159Permalink
How it is measured
Sperm concentration in ejaculate by standard semen analysis (manual haemocytometer counting or computer-assisted sperm analysis), expressed as millions of spermatozoa per millilitre, per WHO semen-analysis methodology.
Measured, not recorded
- Subject
- sperm concentration
- Measurements
- 42 measurements
- Recorded as a finding
- No
Show what was measured
sperm concentration
increases
sperm concentration (RR 5.33, 95 % CI 4.18 to 6.47, I(2) = 58 %)
PMID:23912751 · one of two readings recorded this
sperm concentration
no effect
However, there were no significant effects of zinc supplementation on the sperm viability, sperm concentration, sperm count or percentage of abnormal sperm morphology
PMID:26932683 · one of two readings recorded this
sperm concentration
n = 1164
0-100 | 1164 | 3.2 (2.3-4.3) | 146 (65-257) | 46 (22-80) | 66 (57-74) | 6.5 (3.3-8.5)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 139
0-25 | 139 | 2.8 (2.3-3.8) | 118 (50-206) | 34 (18-78) | 69 (60-76) | 5.5 (3.0-8.5)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 521
101-200 | 521 | 3.2 (2.4-4.1) | 133 (62-242) | 42 (20-78) | 67 (58-74) | 7.0 (4.3-9.5)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 62
175-1075 | 62 | 2.5 (2.2-3.7) | 145 (74-351) | 44 (21-96) | 71 (60-77) | 6.8 (4.0-10.0)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 657
201-800 | 657 | 3.2 (2.4-4.1) | 149 (70-260) | 47 (23-84) | 68 (57-74) | 6.5 (3.5-9.5)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 143
50-125 | 143 | 3.3 (2.1-4.1) | 113 (39.288) | 44 (22-90) | 69 (63-77) | 5.0 (3.0-8.0)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 63
>800 | 63 | 3.0 (2.1-4.1) | 133 (68-192) | 41 (26-64) | 66 (57-74) | 5.5 (3.3-9.3)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 379
0 | 379 | 3.3 (2.4-4.5) | 171 (75-295) | 50 (25-89) | 66 (57-73) | 8.0 (5.0-10.5)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 1759
1-7 | 1759 | 3.2 (2.3-4.2) | 143 (65-254) | 45 (22-80) | 67 (55-74) | 6.0 (3.5-9.5)
PMID:28646871 · one of two readings recorded this
sperm concentration
decreases, n = 93
>14 | 93 | 3.0 (2.2-4.0) | 102 (42-197) | 35 (17-66) | 66 (58-73) | 7.0 (5.0-10.0)
PMID:28646871 · one of two readings recorded this
sperm concentration
n = 262
-14 | 262 | 3.1 (2.4-4.1) | 138 (71-241) | 47 (23-76) | 69 (58-76) | 6.0 (3.5-9.0)
PMID:28646871 · one of two readings recorded this
sperm concentration
no effect
Most of the semen quality parameters (sperm concentration, motility, morphology, volume, and total motile sperm count) were not significantly different between treatment groups at 6 months after randomization
PMID:31910279 · one of two readings recorded this
Sperm concentration
increases, p = 0.011, n = 69
sperm concentration (15.04 ± 5.61 vs. 10.16 ± 3.59, respectively; p = .011)
PMID:32654242 · one of two readings recorded this
Sperm concentration
no effect
Treatment with maca improved the percentage of sperm concentration by 40%, whereas the placebo improved by 76% after 8 and 16 weeks of treatment
PMID:34585449 · one of two readings recorded this
Sperm concentration
no effect
Treatment with maca improved the percentage of sperm concentration by 40%, whereas the placebo improved by 76% after 8 and 16 weeks of treatment
PMID:34585449 · one of two readings recorded this
sperm concentration
increases, p = 0.05
During follow-up, 20 %, 7.4 %, 22 % and 0.7 % increase in serum vitamin D levels, progressive sperm motility, sperm concentration and sperm morphology, respectively, were observed (all p<0.05)
PMID:34918534 · one of two readings recorded this
Sperm concentration
no effect, p = 0.05, n = 438
the six studies showed a high heterogeneity (MD 2.70, 95% CI −2.04 to 7.44; n = 438, RCT = 6, P > 0.05, I2 = 97%)
PMID:35128424 · one of two readings recorded this
Sperm concentration
no effect, p = 0.05, n = 279
the meta-analysis still showed no significant effects of carnitines on sperm concentration (MD 0.79, 95% CI −0.39 to 1.96; n = 279, RCT = 4, P > 0.05, I2 = 0%)
PMID:35128424 · one of two readings recorded this
sperm concentration
increases
VitE and VitC significantly improved progressive motility (standardized mean difference (SMD) 0.38, 95% CI 0.22-0.55), sperm concentration (SMD 0.21, 95% CI 0.09-0.34), sperm morphology (SMD 0.32, 95% CI 0.09-0.55), and total sperm number (SMD 0.28, 95% CI 0.12-0.43)
PMID:35604582 · one of two readings recorded this
sperm concentration
no effect, p = 0.769
increasing sperm concentration (95% CI: -0.21-0.29, SMD = 0.04, p = 0.769)
PMID:36029025 · one of two readings recorded this
sperm concentration
increases, p = 0.01
sperm concentration (8.22 ± 6.88 × 106/mL vs. 12.53 ± 8.11 × 106/mL, p < 0.01)
PMID:36364847 · one of two readings recorded this
sperm concentration
increases, 25.2 million/ml (Group B) vs 16.5 million/ml (Group A) at 3 months, p = 0.02
At the end of the current study, the results revealed significant (p˂0.05) differences between the two groups for all parameters (sperm concentration and total sperm counts) except seminal fluid volume, which was significant only after two months (p>0.05).
PMID:38957201 · one of two readings recorded this
sperm concentration
p = 0.305
Sperm concentration (Mil./ml) | Baseline | 8.9 ± 7.9 a | 7.3 ± 5.2 a | 0.305 NS
PMID:38957201 · one of two readings recorded this
sperm concentration
p = 0.369
First month | 14.1 ± 11.9 b | 11.9 ± 9.2) b | 0.369 NS
PMID:38957201 · one of two readings recorded this
sperm concentration
p = 0.392
Second month | 17.2 ± 14.1 c | 20 ± 14.1 c | 0.392 NS
PMID:38957201 · one of two readings recorded this
sperm concentration
increases, p = 0.02
Third month | 16.5 ± 11.9 d | 25.2 ± 16.5 d | 0.020 *
PMID:38957201 · one of two readings recorded this
sperm concentration
increases, p = 0.001
P value B | < 0.001 ** | < 0.001 **
PMID:38957201 · one of two readings recorded this
sperm concentration
increases, p = 0.001
P value B | < 0.001 ** | < 0.001 **
PMID:38957201 · one of two readings recorded this
Sperm concentration
decreases, p = 0.01
(SMD -0.83 [95% CI: -1.46, -0.20] P = 0.010)
PMID:39250513 · one of two readings recorded this
Sperm concentration
no effect, p = 0.08
(SMD -1.02 [95% CI: -2.16, 0.12] P = 0.08)
PMID:39250513 · one of two readings recorded this
Sperm concentration
decreases, p = 0.004
(SMD -0.42 [95% CI: -0.70, -0.14] P = 0.004)
PMID:39250513 · one of two readings recorded this
Sperm concentration
decreases, p = 0.001
(SMD -0.31 [95% CI: -0.50, -0.12] P = 0.001)
PMID:39250513 · one of two readings recorded this
Sperm concentration
no effect, p = 0.19
(SMD -0.21 [95% CI: -0.53, 0.10] P = 0.19)
PMID:39250513 · one of two readings recorded this
Sperm concentration
no effect, p = 0.39
(SMD -0.18 [95% CI: -0.59, 0.23] P = 0.39)
PMID:39250513 · one of two readings recorded this
Sperm concentration
no effect, p = 0.063
There was a slight improvement in sperm concentration, but it was non-statistically significant (MD 11.99; CI 95% −0.67 to 24.66; p = 0.063; I2 = 92%; Figure-3C)
PMID:40327515 · one of two readings recorded this
Sperm concentration
no effect
5 | randomised trials | not serious | not serious | not serious | not serious | none | 131 | 119 | - | MD 11.99 higher (0.67 lower to 24.66 higher) | ⨁⨁⨁⨁ High | IMPORTANT
PMID:40327515 · one of two readings recorded this
Sperm concentration
increases, p = 0.037
Lycopene supplementation significantly increased sperm concentration compared with control interventions (SMD = 0.33, 95% CI [0.02 to 0.65], p = 0.037)
PMID:40806357 · one of two readings recorded this
Sperm concentration
no effect, p = 0.211
When removing Nouri et al. (2019), the effect size decreased slightly and lost significance (SMD = 0.23, 95% CI [−0.13 to 0.58], p = 0.211)
PMID:40806357 · one of two readings recorded this
Sperm concentration
increases, p = 0.018
the strongest effect emerged when removing Williams et al. (2020) (SMD = 0.47, 95% CI [0.08 to 0.87], p = 0.018)
PMID:40806357 · one of two readings recorded this
sperm concentration
no effect, p = 0.8
sperm concentration (SMD 0.09, 95% CI-0.59 to 0.76; p = 0.80)
PMID:42165159 · one of two readings recorded this
Sources cited
3 papers
- Subject
- sperm concentration
- Findings
- 3
- Papers
- 3
Effect of adjuvant vitamin E supplementation on sperm parameters after varicocelectomy: a systematic review and meta-analysis.record2026PMID:421651591 finding
Evaluation of the effect of Lepidium meyenii Walpers in infertile patients: A randomized, double-blind, placebo-controlled trial.record2021PMID:345854491 finding
Zinc levels in seminal plasma and their correlation with male infertility: A systematic review and meta-analysis.record2016PMID:269326831 finding