Sperm Quality Research Analysis

Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect sperm quality

Grade	Level of Evidence [show legend]
	Robust research conducted with repeated double-blind clinical trials
	Multiple studies where at least two are double-blind and placebo controlled
	Single double-blind study or multiple cohort studies
	Uncontrolled or observational studies only

Outcome	Magnitude of effect ? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.	Consistency of research results ? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.	Notes
L-Carnitine	Notable	High See all 5 studies	Carnitine at 3g daily appears to increase sperm quality mostly related to sperm morphology; there are mixed effects on sperm motility
Mucuna pruriens	Minor	Very High See all 3 studies	There appears to be an increase in seminal quality and oxidative parameters following 3-month ingestion of Mucuna pruriens, which is thought to be secondary to correcting the hypothalamic-pituitary-testes axis
Ashwagandha	Minor	Very High See 2 studies	Appears to enhance seminal quality (in a fairly general sense) but needs more studies against reference drugs to properly assess potency.
Coenzyme Q10	Minor	Moderate See all 4 studies	There may be some beneficial influences on the sperm quality, but they have not been reliably reported
Eurycoma Longifolia Jack
Shilajit
Astaxanthin
Saffron
Tribulus terrestris
Vitamin C
D-Aspartic Acid
Ginger

All comparative evidence is now gathered in our A-to-Z Supplement Reference.

The evidence for each separate supplement is still freely available here.