Ingredients in Tetrasteroneā„¢: List of scientific studies

Tongkat Ali (Eurycoma Longifolia):

Phytoandrogenic properties of Eurycoma longifolia as natural alternative to testosterone replacement therapy.

Eurycomanone, the major quassinoid in Eurycoma longifolia root extract increases spermatogenesis by inhibiting the activity of phosphodiesterase and aromatase in steroidogenesis.

Standardized quassinoid-rich Eurycoma longifolia extract improved spermatogenesis and fertility in male rats via the hypothalamic-pituitary-gonadal axis.

Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects.

Standardised water-soluble extract of Eurycoma longifolia, Tongkat ali, as testosterone booster for managing men with late-onset hypogonadism?

Influence of Eurycoma longifolia on the copulatory activity of sexually sluggish and impotent male rats.

The effect of Eurycoma longifolia on sperm quality of male rats.

Effects of Eurycoma longifolia Jack (Tongkat Ali) on the initiation of sexual performance of inexperienced castrated male rats.

The in vitro and in vivo anti-cancer activities of a standardized quassinoids composition from Eurycomalongifolia on LNCaP human prostate cancer cells.

In vivo effects of Eurycoma longifolia Jack (Tongkat Ali) extract on reproductive functions in the rat.

Eurycoma longifolia as a potential alternative to testosterone for the treatment of osteoporosis: Exploring time-mannered proliferative, differentiative and morphogenic modulation in osteoblasts.

Grapeseed extract:

Grape seed extract is an aromatase inhibitor and a suppressor of aromatase expression.

Suppression of estrogen biosynthesis by procyanidin dimers in red wine and grape seeds.

Effects of grape seed polyphenols on oxidative damage in liver tissue of acutely and chronically exercised rats.

Grape seed extract enhances eNOS expression and NO production through regulating calcium-mediated AKT phosphorylation in H2O2-treated endothelium.

Effect of grape seed extract on blood pressure in subjects with the metabolic syndrome.

The effect of grape seed extract on cardiovascular risk markers: a meta-analysis of randomized controlled trials.

Effects of grape seed extract consumption on platelet function in postmenopausal women.

Effects of marjoram volatile oil and grape seed extract on ethanol toxicity in male rats.


The role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and rats

D-Aspartic acid: an endogenous amino acid with an important neuroendocrine role.

Involvement of D-aspartic acid in the synthesis of testosterone in rat testes.


Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines.

The effect of boron supplementation on its urinary excretion and selected cardiovascular risk factors in healthy male subjects.

The significance of dietary boron, with particular reference to athletes.

Nothing Boring About Boron.

Vitamin D:

Association of vitamin D status with serum androgen levels in men.

Plausible ergogenic effects of vitamin D on athletic performance and recovery.

Effect of vitamin D supplementation on testosterone levels in men.

Hip fracture in elderly men: the importance of subclinical vitamin D deficiency and hypogonadism.

Association between plasma 25-OH vitamin D and testosterone levels in men


Vitamin D is positively associated with sperm motility and increases intracellular calcium in human spermatozoa.

Vitamin D is necessary for reproductive functions of the male rat.

Males with low serum levels of vitamin D have lower pregnancy rates when ovulation induction and timed intercourse are used as a treatment for infertile couples: results from a pilot study.


Zinc status and serum testosterone levels of healthy adults.

The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zinc.

Effect of fatiguing bicycle exercise on thyroid hormone and testosterone levels in sedentary males supplemented with oral zinc.

Impact of oral zinc therapy on the level of sex hormones in male patients on hemodialysis.

Effect of zinc administration on plasma testosterone, dihydrotestosterone, and sperm count.