What Drug Can Reverse Gynecomastia?

October 7, 2025 •

4 min read

Gynecomastia is the most common benign disorder of the male breast, affecting an estimated 35% of men [1.8.4]. While often resolving on its own, for persistent cases, the question arises: what drug can reverse gynecomastia? Medical treatments aim to correct the underlying hormonal imbalance [1.9.4].

Quick Summary

Pharmacological treatments for gynecomastia focus on correcting the estrogen-androgen imbalance. Medications like tamoxifen and raloxifene (SERMs) are used off-label to block estrogen's effects on breast tissue and have shown notable success in reducing breast size, especially in recent-onset cases.

Key Points

Primary Medications: Tamoxifen and raloxifene, both Selective Estrogen Receptor Modulators (SERMs), are the most effective drugs for treating gynecomastia by blocking estrogen at the breast tissue [1.3.1, 1.5.2].
Off-Label Use: Currently, no drugs are specifically FDA-approved for treating gynecomastia; all pharmacological treatments are considered off-label [1.3.3, 1.10.2].
Timing is Crucial: Medical therapy is most successful for recent-onset gynecomastia (less than one year) before the glandular tissue becomes fibrotic [1.2.3, 1.8.5].
Aromatase Inhibitors Ineffective: Despite a logical mechanism, aromatase inhibitors like anastrozole have not proven more effective than placebo in clinical trials and are not recommended [1.6.2, 1.6.3].
Tamoxifen Efficacy: Tamoxifen is the most studied drug, with up to 80% of patients reporting partial or complete resolution, and it is particularly good for resolving pain [1.4.3, 1.4.1].
Raloxifene as an Alternative: Some studies suggest raloxifene may lead to greater size reduction than tamoxifen, with a significant decrease seen in up to 86% of patients in one study [1.5.2].
Surgery is Definitive: For long-standing or severe gynecomastia, surgical removal of the glandular tissue is the most effective and permanent solution [1.2.3, 1.8.4].

Understanding Gynecomastia and Its Causes

Gynecomastia is the enlargement of glandular breast tissue in males, distinct from pseudogynecomastia, which is fat accumulation without glandular proliferation [1.9.4]. The condition stems from an imbalance between estrogen and androgen hormones [1.9.4]. While testosterone typically inhibits breast tissue growth, an increased estrogen-to-androgen ratio stimulates it [1.3.5].

This hormonal shift can be physiological, occurring in three main life stages:

Infancy: 60-90% of newborns experience temporary gynecomastia due to maternal estrogens, which usually resolves in weeks [1.8.4].
Puberty: Up to 70% of adolescent boys may develop gynecomastia due to transient hormonal fluctuations. It typically resolves within one to three years [1.8.4, 1.9.4].
Older Adulthood: Prevalence is estimated between 24% and 65% in men over 50, often due to declining testosterone and increased body fat, which enhances the conversion of androgens to estrogens [1.8.4].

Non-physiological causes include medications (e.g., spironolactone, some antidepressants), anabolic steroid use, chronic liver or kidney disease, hypogonadism, and certain tumors [1.2.1, 1.8.5]. In about 25% of cases, no specific cause is found, termed idiopathic gynecomastia [1.8.3].

Pharmacological Approaches: What Drug Can Reverse Gynecomastia?

While no drugs are specifically FDA-approved for gynecomastia, several are used off-label with varying success [1.3.3, 1.10.2]. Medical therapy is most effective in cases of recent onset (less than a year), when the condition is still in the proliferative phase and has not yet developed significant fibrosis or hyalinization [1.2.3, 1.5.2].

Selective Estrogen Receptor Modulators (SERMs)

SERMs work by competitively binding to estrogen receptors in breast tissue, blocking estrogen's stimulating effects [1.2.2]. This makes them a primary option for medical management.

Tamoxifen: As the most studied drug for gynecomastia, tamoxifen has shown significant efficacy [1.4.1]. Dosed typically at 10-20 mg daily for 3 to 6 months, studies report partial to complete resolution in up to 80% of patients, particularly those with recent-onset, tender gynecomastia [1.4.1, 1.4.3]. It is especially effective at resolving breast pain [1.4.1]. Some studies show it is more effective for the glandular 'lump' type of gynecomastia compared to the diffuse 'fatty' type [1.4.4].
Raloxifene: This second-generation SERM has also been used effectively. Some research suggests it may be more effective than tamoxifen in achieving a significant reduction in breast size. One study on persistent pubertal gynecomastia found that 86% of patients on raloxifene had a greater than 50% decrease in breast nodule diameter, compared to 41% with tamoxifen [1.5.2]. It also appears to have a lower recurrence rate in some follow-ups [1.9.4].

Aromatase Inhibitors (AIs)

AIs, such as anastrozole and letrozole, work by blocking the aromatase enzyme, which converts androgens into estrogens, thereby lowering overall estrogen levels [1.3.5]. While this mechanism seems logical for treating gynecomastia, clinical results have been disappointing. A major randomized, double-blind, placebo-controlled study found no statistically significant difference between anastrozole and a placebo in reducing breast volume [1.6.2]. Due to this lack of proven efficacy, AIs are generally not recommended as a first-line treatment [1.2.1, 1.6.3].

Other Medical Options

Androgens (Testosterone, Danazol): Testosterone replacement therapy is only considered effective for men with proven hypogonadism (low testosterone) [1.2.2]. In men with normal testosterone levels, it can paradoxically worsen gynecomastia by providing more substrate for aromatization into estrogen [1.2.1]. Danazol, a weak synthetic androgen, has shown mixed success, with one report of 23% complete resolution, but it carries side effects like weight gain and acne [1.7.1].
Clomiphene: This antiestrogen has also been tried, with one study showing a 64% partial response rate [1.2.1]. However, other analyses suggest it results in only small decreases in breast size and is not considered a satisfactory therapy [1.2.4].

Comparison of Treatments


Treatment Option	Mechanism of Action	Reported Success Rate	Key Considerations
Tamoxifen	Blocks estrogen receptors in breast tissue [1.4.3]	Up to 80% partial to complete resolution [1.4.3]	Most studied drug; effective for recent, painful cases; low side-effect profile [1.2.1, 1.9.5].
Raloxifene	Blocks estrogen receptors in breast tissue [1.5.2]	86-93% of patients saw >50% reduction in some studies [1.5.2, 1.9.4]	May be more effective than tamoxifen for size reduction; no recurrence reported in some studies [1.5.2, 1.9.4].
Aromatase Inhibitors	Inhibit the conversion of androgens to estrogens [1.6.1]	Generally not shown to be more effective than placebo [1.6.2, 1.6.3]	Not recommended as first-line treatment due to lack of efficacy in clinical trials [1.2.1].
Surgery	Physical removal of glandular tissue and/or fat [1.8.4]	95-98% patient satisfaction rate [1.9.1]	Definitive treatment, especially for long-standing cases; carries surgical risks and higher cost [1.2.3, 1.9.3].

The Definitive Solution: Surgery

For gynecomastia that has persisted for more than a year or two, the glandular tissue often becomes fibrotic and is unlikely to respond to medical therapy [1.2.3, 1.8.5]. In these instances, and for patients with severe gynecomastia or significant psychological distress, surgical intervention is the most effective and definitive treatment [1.8.4]. Surgical options include liposuction to remove excess fat and mastectomy to excise the glandular tissue [1.8.4]. While highly effective, with patient satisfaction rates over 95%, it is a more invasive and costly option [1.9.1].

Conclusion

Pharmacological treatment, particularly with Selective Estrogen Receptor Modulators like tamoxifen and raloxifene, can be an effective strategy to reverse gynecomastia, especially when the condition is of recent onset and causing pain. These drugs work by directly blocking estrogen's effects on the breast tissue. While aromatase inhibitors have a logical mechanism of action, they have not proven effective in clinical trials and are not recommended. For long-standing, fibrotic gynecomastia, surgery remains the gold standard for achieving a permanent and satisfactory aesthetic outcome. Any treatment should be pursued under the guidance of a qualified healthcare provider to address the underlying cause and choose the most appropriate intervention.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional for diagnosis and treatment of any medical condition.

For more information from an authoritative source, you can visit the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): https://www.niddk.nih.gov/health-information/endocrine-diseases/gynecomastia

Frequently Asked Questions

Tamoxifen is the most studied and commonly used drug, showing resolution in up to 80% of patients with recent-onset gynecomastia. Some studies suggest raloxifene may be even more effective for size reduction [1.4.3, 1.5.2].

Drugs like tamoxifen and raloxifene can lead to partial or even complete resolution, especially if the condition is treated early (within the first year). However, for long-standing gynecomastia, surgery is often required for a complete correction [1.2.3, 1.9.2].

Tamoxifen and raloxifene are generally well-tolerated with minimal side effects in the short-term courses used for gynecomastia. Common side effects can include nausea and epigastric discomfort, but serious adverse events are rare [1.4.3, 1.5.2, 1.9.5].

A course of treatment with a SERM like tamoxifen is typically 3 to 6 months [1.4.1]. Noticeable improvements in pain can occur within a month, with size reduction observed over the full course of therapy [1.9.4].

No, clinical trials have shown that aromatase inhibitors like anastrozole are not significantly more effective than a placebo for treating gynecomastia. They are generally not recommended for this purpose [1.2.1, 1.6.3].

Testosterone therapy is only effective if the gynecomastia is caused by hypogonadism (clinically low testosterone). In men with normal testosterone levels, it can worsen the condition by being converted into estrogen [1.2.1, 1.2.2].

Surgery is the recommended treatment for gynecomastia that has been present for over a year, as the tissue often becomes fibrous and unresponsive to medication. It is also the best option for severe cases or when a patient desires a definitive correction [1.2.3, 1.8.5].