Herbal Causes of Gynecomastia

Herbal supplements can cause gynecomastia through mechanisms that alter the estrogen-to-androgen ratio in the body. 1, 2

Common Herbal Supplements Associated with Gynecomastia

Phytoestrogens (plant-derived compounds with estrogen-like effects) can contribute to gynecomastia by increasing estrogen activity in breast tissue 1
Herbal products that contain or mimic estrogen compounds can disrupt the normal hormonal balance, leading to breast tissue proliferation 2
Supplements marketed for bodybuilding or "natural testosterone boosting" may paradoxically cause gynecomastia through conversion to estrogen 1

Herbal supplements can cause gynecomastia through:
- Direct estrogenic activity (binding to estrogen receptors) 1
- Inhibition of androgen production or action 2
- Increasing peripheral conversion of androgens to estrogens 1
- Disruption of the hypothalamic-pituitary-gonadal axis 2

Lavender and tea tree oils have been reported to cause prepubertal gynecomastia due to their estrogenic and anti-androgenic properties 2
Dong quai, ginseng, and soy products contain phytoestrogens that may contribute to gynecomastia 1
Saw palmetto, despite being used to treat prostate conditions, has been associated with gynecomastia in some case reports 2

Pre-existing hormonal imbalances increase susceptibility to herbal-induced gynecomastia 1
Liver disease impairs metabolism of both endogenous hormones and herbal compounds, increasing risk 3, 1
Concurrent use of medications known to cause gynecomastia potentiates the effects of herbal supplements 2
Obesity increases risk through peripheral conversion of androgens to estrogens in adipose tissue 1

Detailed supplement history is crucial, including:
- Specific herbal products used 2
- Duration of use 2
- Temporal relationship between supplement initiation and onset of gynecomastia 1
Physical examination to differentiate true gynecomastia (glandular tissue) from pseudogynecomastia (adipose tissue) 2
Laboratory evaluation may include:
- Serum estradiol levels 2
- Testosterone levels 2
- Liver function tests to assess for impaired metabolism 3, 1

Discontinuation of the suspected herbal supplement is the first-line intervention 2
Gynecomastia often resolves spontaneously within months after removing the causative agent 2
For persistent, painful gynecomastia:
- Estrogen receptor modulators may be considered 2
- Surgical intervention may be necessary for gynecomastia that persists beyond 12 months and becomes fibrotic 2

Failing to obtain a complete supplement history, including over-the-counter and "natural" products 2
Not recognizing that many patients may not consider herbal supplements as "medications" when providing medical history 1
Overlooking the possibility of contamination of herbal products with undisclosed hormones or pharmaceutical compounds 2
Distinguishing between true gynecomastia and pseudogynecomastia, especially in obese patients 2

Educate patients about potential hormonal effects of herbal supplements 1
Advise caution with supplements marketed for bodybuilding or male enhancement 2
Recommend purchasing supplements from reputable sources to minimize risk of contamination 1
Suggest periodic breast self-examination for patients on long-term herbal therapies with known estrogenic effects 2