Can boron, Stinging nettle, Pygeum, Soy lecithin, Trimethoprim (TMP), and Alfuzosin cause testicular atrophy?

Testicular Atrophy Risk from Boron, Stinging Nettle, Pygeum, Soy Lecithin, Trimethoprim, and Alfuzosin

None of these substances—boron, stinging nettle, pygeum, soy lecithin, trimethoprim, or alfuzosin—have established evidence linking them to testicular atrophy in clinical practice.

Evidence-Based Analysis by Substance

Endothelin Antagonists (Not Your Listed Substances)

The only relevant guideline evidence regarding testicular atrophy concerns endothelin receptor antagonists (bosentan, sitaxsentan), which are not among your listed substances 1. These medications carry a class concern for potential testicular atrophy and male infertility, requiring counseling for younger men considering conception 1.

Your Listed Substances: Lack of Evidence

Stinging Nettle (Urtica dioica):

• Research demonstrates effects on sex hormone-binding globulin and hormonal signaling pathways 2
• Studies show use in benign prostatic hyperplasia without reported testicular effects 3, 4
• No documented cases or studies linking stinging nettle to testicular atrophy
• Reported adverse effects include galactorrhea through hormonal mechanisms, but not testicular damage 2

Pygeum africanum:

• Clinical trials in BPH patients show no testicular toxicity signals 3
• No evidence in medical literature connecting pygeum to testicular atrophy

Boron, Soy Lecithin:

• No evidence found linking these supplements to testicular atrophy
• Not mentioned in reproductive toxicology guidelines 1

Trimethoprim:

• No established association with testicular atrophy in clinical use
• Not identified as a gonadotoxic agent in fertility preservation guidelines 1

Alfuzosin (Alpha-blocker):

• No documented testicular atrophy risk
• Not listed among medications affecting testicular function in urology guidelines 1

Known Causes of Testicular Atrophy for Context

The established causes of testicular atrophy and reduced testicular volume include 1:

• Alkylating chemotherapy agents (cyclophosphamide >7.5 g/m², busulfan >600 mg/m²)
• Testicular radiation ≥2 Gy for germ cell dysfunction, ≥20 Gy for Leydig cell dysfunction
• Cryptorchidism (undescended testes)
• Varicocele (associated with progressive testicular volume reduction)
• Testicular cancer and its treatments
• Klinefelter syndrome and genetic disorders 1

Clinical Implications

If testicular atrophy is present:

• Investigate established causes listed above rather than attributing to these supplements 1
• Perform hormonal evaluation (testosterone, LH, FSH, inhibin B) 1
• Consider testicular ultrasound to assess volume and rule out structural pathology 1
• Evaluate for varicocele, cryptorchidism history, or prior gonadotoxic exposures 1

Regarding supplement use:

• While these substances lack evidence for testicular atrophy, environmental contaminants and endocrine disruptors can affect testicular function through multiple mechanisms 5, 6
• Medication reconciliation should include all supplements, as they may have other hormonal effects 2