Yes, finasteride can cause gynecomastia (breast enlargement in men) as a potential side effect. Finasteride is a medication primarily used to treat conditions like benign prostatic hyperplasia (BPH) and male pattern hair loss by inhibiting the enzyme 5-alpha-reductase. This enzyme converts testosterone into dihydrotestosterone (DHT), a hormone that contributes to prostate growth and hair loss.

By reducing DHT levels, finasteride can also affect the balance of hormones in the body. The resulting hormonal changes may, in rare cases, lead to an increase in estrogen relative to androgens, which can cause gynecomastia.

Important Considerations:

• Frequency: Gynecomastia is a relatively rare side effect, but still possible.
• Onset: If gynecomastia occurs, it typically develops gradually over months of use.
• Reversibility: In many cases, discontinuing the medication can lead to a reduction in breast enlargement, but this may not always be fully reversible, especially if the condition has persisted for a long time.

If you notice symptoms of breast tenderness or enlargement while using finasteride, it's recommended to consult with a healthcare provider to discuss the risks and potential treatment options.

Some other common negative side-effects from taking finasteride

Some potential negative side effects of finasteride include:

• Sexual dysfunction: Decreased libido, erectile dysfunction, and reduced semen volume.
• Depression or mood changes.
• Allergic reactions: Skin rash, itching, or swelling.
• Potential risk of high-grade prostate cancer.

Most side effects often resolve after discontinuing the medication, but some may persist.