No Supplements Can Increase Testicle Size
There are no supplements that can increase testicle size in healthy men, and attempting to do so without addressing underlying pathology is inappropriate. Testicular size is determined by the degree of active spermatogenesis and Leydig cell mass, not by nutritional supplementation 1, 2.
Understanding Testicular Size and Function
Testicular volume reflects the functional status of spermatogenesis, not a cosmetic feature amenable to supplementation 2. Normal adult testicular volume ranges from 15-25 mL, with volumes below 12 mL indicating testicular atrophy and impaired spermatogenesis 2.
The only circumstances where testicular size can be increased involve treating specific underlying hormonal deficiencies:
Hypogonadotropic Hypogonadism (Secondary Hypogonadism)
- In men with hypogonadotropic hypogonadism, gonadotropin therapy (hCG followed by FSH) can increase testicular volume from 2-4 mL to 10-18 mL over 12-24 months 3, 4, 5.
- This requires documented low testosterone with low or low-normal LH and FSH levels 1.
- Treatment involves hCG injections (1500-3000 IU twice weekly) to stimulate testosterone production, followed by FSH analogues if needed to initiate spermatogenesis 1, 3.
- Pulsatile GnRH therapy (2-20 mcg per pulse every 90 minutes intravenously) can achieve similar testicular growth 4, 5.
Critical Contraindications
Exogenous testosterone therapy causes testicular atrophy, not growth 1. Testosterone provides negative feedback to the hypothalamus and pituitary, suppressing LH and FSH secretion, which eliminates intratesticular testosterone production and causes spermatogenesis to cease, resulting in testicular shrinkage 1, 2.
Supplements and Testicular Size: The Evidence
A comprehensive scoping review found that most nutraceuticals lack evidence for improving testosterone levels or sperm parameters 6. The few supplements with modest effects on testosterone or sperm quality (zinc, vitamin D in deficiency states, L-arginine, ashwagandha) do not increase testicular size 6.
No supplement has been shown to increase testicular volume in controlled trials 6.
When Small Testicles Require Evaluation
Small testicular volume (<12 mL) warrants medical evaluation, not supplementation 2:
- Measure morning total testosterone, LH, FSH, and prolactin 1, 2.
- Obtain karyotype analysis and Y-chromosome microdeletion testing if FSH is elevated (>7.6 IU/L) with testicular atrophy 1, 2.
- Evaluate for varicocele on physical examination, as surgical repair can improve testicular function in appropriate candidates 2.
Special Circumstance: Scrotal Hypoplasia in Children
In prepubertal boys with scrotal hypoplasia or agenesis, topical testosterone (Testogel 1%) for 4 weeks increased scrotal surface area and rugae in 85% of unilateral cases and 60% of bilateral cases 7. This represents scrotal skin development, not testicular growth, and is only applicable to pediatric patients with congenital scrotal underdevelopment 7.
Common Pitfalls to Avoid
- Never use testosterone therapy if fertility is desired or testicular size preservation is a goal 1, 2. Testosterone causes testicular atrophy through suppression of gonadotropins.
- Do not use testosterone therapy in eugonadal men 1. This is a strong recommendation from the European Association of Urology.
- Avoid anabolic steroids completely, as these suppress FSH and LH, causing azoospermia and testicular atrophy that can take months to years to recover 2.
- Lifestyle modifications (weight loss, exercise) can modestly improve testosterone levels (1-2 nmol/L) in functional hypogonadism but do not increase testicular size 1.
The Bottom Line
If testicular size is genuinely small (<12 mL), seek evaluation by a reproductive endocrinologist or urologist to identify treatable causes 2. If testicles are normal size (15-25 mL), no intervention is indicated or beneficial. Supplements marketed for testicular enhancement lack scientific support and should be avoided 6.